External voltage withstanding test device of power transformer

Abstract

The invention belongs to the technical field of voltage withstanding tests of transformers, and particularly relates to an externally applied voltage withstanding test device of a power transformer, which comprises a supporting plate, universal wheels are mounted at four corners of the lower end surface of the supporting plate, a base is mounted on the upper end surface of the supporting plate, a limiting seat is fixedly connected to the upper end surface of the base, and a resistance tube is mounted in an inner cavity of the limiting seat. A protective shell is installed outside the resistance tube, fastening bolts are rotationally connected to the positions, located at the four corners, of the upper end face of the protective shell, the fastening bolts are in threaded connection with the base, and an adjusting assembly is arranged outside the resistance tube, so that the problems that power needs to be cut off during adjustment every time, and if power is not cut off, a metal contact and a resistance wire contact point are directly adjusted; if the resistance wire is broken, the metal contact and the resistance wire are rubbed to generate high temperature, so that the breakage and damage time of the resistance wire is shortened, and if the service lives of the resistance wire and the metal contact are prolonged, the conditions of poor contact and unstable resistance value still occur due to long-time friction between the metal contact and the resistance wire when the power is cut off for adjustment.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer withstand voltage test, in particular to an externally applied withstand voltage test device for a power transformer. Background Art

[0002] In the manufacturing and maintenance process of power transformers, external applied voltage withstand test is an important link to ensure the quality and safety of transformers. The existing external applied voltage withstand test equipment for power transformers usually includes an adjustable voltage source and a resistor box connected to it. The voltage applied to the transformer is changed by adjusting the resistance value of the resistor box, thereby achieving the test purpose.

[0003] A patent with publication number CN116736056B discloses an externally applied voltage withstand test device for a power transformer. The patent drives a transmission mechanism through a power mechanism to make a slider slide, thereby driving a paddle to slide on the outer wall of a resistor tube, thereby changing the resistance value of the resistor tube and causing the resistance to change, thereby controlling the test device to pressurize the transformer. The set slide rail can improve the stability of the slider when sliding, making the test of the test device more accurate. Through the set elastic mechanism, the paddle can be pushed to make it close to the resistor tube to avoid the paddle loosening and separation from the resistor tube, resulting in inaccurate test data. The set detection device can be used to apply pressure to the transformer and perform a pressure test on the transformer.

[0004] There are still some problems in the actual application of the above scheme. Usually, fixed resistors or adjustable resistors are used to perform voltage withstand tests on transformers. The resistance of fixed resistors is fixed and cannot adapt to the test requirements of different voltage levels. Although adjustable resistors can adapt to the test requirements of different voltage levels by adjusting the resistance, each adjustment requires power failure, and then the metal contact and the resistance wire are controlled to contact to achieve the change of resistance. If the power is not turned off for adjustment, the metal contact and the resistance wire will rub against each other, and the voltage will generate high temperature, thereby accelerating the breakage and damage of the resistance wire. When the power is turned off to adjust the contact position of the metal contact and the resistance wire, since the metal contact and the resistance wire are closely attached, long-term use and adjustment will also cause wear due to friction, resulting in poor contact and unstable resistance, thereby affecting the accuracy of the test results.

[0005] To this end, the present invention provides an externally applied voltage withstand test device for a power transformer. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows: the externally applied withstand voltage test device of a power transformer described in the present invention comprises a support plate, the lower end surface of the support plate is provided with universal wheels at four corners, the upper end surface of the support plate is provided with a base, the upper end surface of the base is fixedly connected with a limit seat, a resistor tube is provided in the inner cavity of the limit seat, a protective shell is provided outside the resistor tube, the upper end surface of the protective shell is provided with fastening bolts rotatably connected in the four corners, and the fastening bolts are threadedly connected with the base, and an adjustment component is provided outside the resistor tube;

[0008] The adjustment assembly includes two threaded rods rotatably connected to the inner cavity of the protective shell, and the two threaded rods are externally threadedly connected to a sliding frame for driving the sliding frame to move up and down in the inner cavity of the protective shell to adjust the position;

[0009] Two mounting plates are symmetrically mounted on the inner wall of the sliding frame, and sliding columns are slidably connected inside the two mounting plates. A paddle is fixedly connected to one end of the sliding column to drive the sliding column to drive the paddle to fit and contact the resistor tube.

[0010] Preferably, a transmission groove is opened inside the upper end surface of the protective shell, one end of the two threaded rods passes through the protective shell and is fixedly connected to the inner cavity of the transmission groove. The second bevel gear is meshingly connected to the first bevel gear, and a transmission shaft is fixed inside the first bevel gear, and the transmission shaft is rotatably connected to the inner wall of the transmission groove.

[0011] Preferably, the upper end surface of the protective shell is rotatably connected to a crank, one end of the crank passes through the protective shell and is located in the inner cavity of the transmission groove and is fixedly connected to a transmission bevel gear, the transmission bevel gear is meshingly connected to a driven bevel gear, and the driven bevel gear is fixed to the outside of the transmission shaft for driving the transmission shaft to rotate.

[0012] Preferably, through slots are provided on both sides of the sliding frame, a first spring is fixedly connected to one end surface of the mounting plate, and the first spring slides in the inner cavity of the through slot, a stop block is fixedly connected to one end of the first spring, and the stop block is fixedly connected to one end of the sliding column.

[0013] Preferably, two wave blocks are symmetrically fixed to the two walls of the inner cavity of the protective shell, and the abutment block is slidably connected to the wave block, which is used to drive the paddle to abut the resistor tube to perform an external withstand voltage test of the transformer. The protective shell is made of insulating wooden material, and a plurality of cross grooves are evenly opened at the front and rear ends of the protective shell, and scale grooves are opened on the front and rear end surfaces of the protective shell on one side of the cross groove to display the size of the voltage adjustment.

[0014] Preferably, a display block is slidably connected to the inner cavity of the cross groove, and the display block is arranged in a semicircular shape at the recessed part of the wave block, and the display block is fixedly connected to connecting blocks on both sides of the inner cavity of the cross groove, and a second spring is fixedly connected to one end of the connecting block, and one end of the second spring abuts against the inner wall of the cross groove, so as to display the position of the pick outside the resistor tube.

[0015] Preferably, a support frame is installed on one side of the protective shell, a slide groove is formed on one side of the support frame, a slot is opened on the inner wall of the slide groove, a third spring is fixedly connected to the upper wall of the inner cavity of the slide groove, and a grounding component is fixedly connected to one end of the third spring, wherein the slot is used to receive the grounding component.

[0016] Preferably, the grounding component includes a slider sliding in the inner cavity of a slide groove, a grounding column is installed on one side of the lower end of the slider, a conductive slide column is fixedly connected to the inner cavity of the slide groove, an annular carbon brush is arranged inside the slider, and the annular carbon brush is slidably connected to the outside of the conductive slide column, and the annular carbon brush is used to transmit the overload voltage to the grounding column.

[0017] Preferably, grooves are provided at both ends of the slider, an elastic member is fixedly connected to the bottom of the inner cavity of the groove, an insert block is fixedly connected to one end of the elastic member, and the insert block is slidably connected to the inner cavity of the groove, a traction rope is fixedly connected to one end of the insert block in the inner cavity of the groove, a handle is fixedly connected to one end of the traction rope, and the handle is slidably connected to the inside of the slider.

[0018] Preferably, a pull rod assembly is installed on one side of the upper end surface of the support plate, and the pull rod assembly includes a fixed block fixedly connected to one side of the end surface of the support plate, a rotating groove is opened inside the fixed block, a rotating column is rotatably connected to the inner cavity of the rotating groove, both ends of the rotating column pass through the fixed block and are fixedly connected to the rotating block, one end of the rotating block is fixedly connected to a pull rod, the rotating column is located outside the inner cavity of the rotating groove and is fixedly connected to a fixed disk, both end surfaces of the fixed disk are fixedly connected to torsion springs, and the torsion springs are fixedly connected to the inner wall of the rotating groove.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The externally applied voltage withstand test device for power transformers described in the present invention drives the sliding frame of the adjustment component to move in the inner cavity of the protective shell, so that the sliding frame drives the sliding column to move upward, and drives the paddle to move synchronously, so as to adjust the position of the paddle in contact with the surface of the resistor tube. When the paddle is located at the bottom of the resistor tube, the resistance will increase, and the voltage transmitted to the transformer will decrease. As the paddle continues to move upward, the resistance will gradually decrease, thereby increasing the voltage transmitted to the transformer. In the initial stage, the paddle is at the bottom of the inner cavity of the protective shell, and the voltage transmitted to the transformer is gradually increased by driving the paddle upward, thereby improving the stability of the transformer voltage withstand test. The contact position of the paddle and the resistor tube is displayed in real time by abutting the display block through the abutment block, thereby further improving the accuracy of the adjustment, thereby solving the problem that the voltage transmitted to the transformer in the existing externally applied voltage withstand test device for transformers is inconvenient to control, so that when the transformer is subjected to the voltage withstand test, excessive voltage is directly transmitted to the transformer, resulting in transformer overload, and causing damage to the transformer or the test device.

[0021] 2. The externally applied voltage withstand test device for power transformers described in the present invention drives the grounding component to disengage from the slot before the voltage withstand test is performed on the transformer, driving the grounding column to contact the ground, so that when the electrical equipment leaks or the voltage is too high, the current is conducted to the conductive sliding column through the ground wire, and at the same time, it is conducted to the annular carbon brush through the conductive sliding column, and then conducted to the ground through the annular carbon brush using the grounding column, thereby increasing the safety of the experiment. When the mobile test device needs to be transported, the grounding column is driven to move upward by driving the grounding component, so that the grounding component is fixedly connected to the slot for storage, thereby improving the convenience of using the voltage withstand test device, thereby solving the problem that the grounding column of the existing externally applied voltage withstand test device for power transformers is usually fixedly installed with the voltage withstand test device, resulting in the grounding column being inevitably bumped into when the mobile voltage withstand test device is transported, causing the grounding column to break or the internal line to short-circuit, affecting the grounding column's conduction efficiency for overload voltage, and affecting the safety of the voltage withstand test device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] Figure 1 It is a schematic diagram of the structure of the main view of the present invention as a whole;

[0024] Figure 2 It is a schematic diagram of the structure of the left-side stereoscopic view of the present invention;

[0025] Figure 3 It is a schematic diagram of the internal structure of the protective housing of the present invention in half section;

[0026] Figure 4 It is a schematic diagram of a partial cross-sectional structure of the protective housing of the present invention;

[0027] Figure 5 It is a schematic diagram of the overall structure of the regulating assembly of the present invention;

[0028] Figure 6 It is a schematic diagram of the internal structure of the sliding frame of the present invention in half section;

[0029] Figure 7 It is a schematic diagram of the overall structure of the grounding assembly of the present invention;

[0030] Figure 8 This is a schematic diagram of the internal structure of a half-section of a slider of the present invention;

[0031] Fig. 9 This is a half-section schematic diagram of the internal structure of the fixing block of the present invention;

[0032] In the figure: 1. support plate; 2. base; 3. protective shell; 4. support frame;

[0033] 5. Tie rod assembly; 51. Fixed block; 52. Rotating groove; 53. Rotating column; 54. Rotating block; 55. Tie rod; 56. Fixed plate; 57. Torsion spring;

[0034] 6. Grounding assembly; 61. Sliding block; 62. Grounding column; 63. Groove; 64. Elastic member; 65. Traction rope; 67. Handle; 68. Annular carbon brush; 69. Conducting sliding column; 610. Insert block;

[0035] 7. Adjustment assembly; 71. Crank handle; 72. Transmission bevel gear; 73. Driven bevel gear; 74. Transmission shaft; 75. First bevel gear; 76. Second bevel gear; 78. Threaded rod;

[0036] 8. Scale groove; 9. Slot; 10. Universal wheel; 11. Sliding frame; 12. Mounting plate; 13. Paddle; 14. Stop block; 15. Sliding column; 16. Through groove; 17. First spring; 18. Cross through groove; 19. Second spring; 20. Display block; 21. Connecting block; 22. Wave block; 23. Resistor tube; 24. Transmission groove; 25. Limit seat; 26. Fastening bolt; 27. Sliding groove; 28. Third spring. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0038] Embodiment 1

[0039] like Figures 1 to 9As shown, an externally applied withstand voltage test device for a power transformer according to an embodiment of the present invention comprises a support plate 1, universal wheels 10 are installed at the four corners of the lower end surface of the support plate 1, a base 2 is installed at the upper end surface of the support plate 1, a limit seat 25 is fixedly connected to the upper end surface of the base 2, a resistor tube 23 is installed in the inner cavity of the limit seat 25, a protective shell 3 is installed outside the resistor tube 23, a fastening bolt 26 is rotatably connected to the upper end surface of the protective shell 3 at the four corners, and the fastening bolt 26 is threadedly connected to the base 2, and an adjustment component 7 is arranged outside the resistor tube 23;

[0040] The adjustment assembly 7 includes two threaded rods 78 rotatably connected to the inner cavity of the protective shell 3, and the two threaded rods 78 are externally threadedly connected to the sliding frame 11, which is used to drive the sliding frame 11 to move up and down in the inner cavity of the protective shell 3 to adjust the position;

[0041] Two mounting plates 12 are symmetrically mounted on the inner wall of the sliding frame 11, and a sliding column 15 is slidably connected inside the two mounting plates 12. A paddle 13 is fixedly connected to one end of the sliding column 15, which is used to drive the sliding column 15 to drive the paddle 13 to fit and contact the resistor tube 23. The entire adjustment component 7 is made of insulating material, and is used to adjust the position of the paddle 13 without cutting off the power.

[0042] Specifically, in the prior art, a metal contact and a resistance wire are usually used to change the resistance value so as to adapt it to the test requirements of different voltage levels. However, each time the adjustment is made, the power needs to be turned off. If the contact point between the metal contact and the resistance wire is adjusted directly without turning off the power, the friction between the metal contact and the resistance wire will cause high temperature, thereby accelerating the breakage and damage time of the resistance wire. Although the adjustment is made by turning off the power, the service life of the resistance wire and the metal contact is increased, the long-term friction between the metal contact and the resistance wire will still cause poor contact and unstable resistance value, thereby affecting the accuracy of the transformer withstand voltage test results.

[0043] When the transformer is subjected to a withstand voltage test, the present invention uses the universal wheel 10 to carry and move the external withstand voltage test device. When it is moved to the transformer, the power cord of the external withstand voltage test device is correctly connected to the output end of the transformer to be tested in accordance with the electrical safety specification. At the same time, the connecting wire of the transformer to be tested is connected to the grounding column of the external withstand voltage test device, thereby completing the preparation work for the transformer test. Then, the threaded rod 78 is driven to rotate, and the threaded transmission sliding frame 11 of the threaded rod 78 moves upward from the bottom of the inner cavity of the protective shell 3, and then the sliding frame 11 drives the mounting plate 12 to move synchronously. At the same time, the mounting plate 12 drives the sliding column 15 to move upward, and then drives the paddle 13 to move synchronously. In the process of moving, the sliding column 15 is used to abut against the inner wall of the protective shell 3, and then the paddle 13 is pushed to abut and fit with the resistor tube 23, and then the external withstand voltage test of the power transformer is carried out. As the threaded rod 78 is continuously rotated, the threaded rod 78 drives the sliding frame 11 to move upward from the bottom of the inner cavity of the protective shell 3, and then the sliding frame 11 drives the mounting plate 12 to move synchronously. At the same time, the mounting plate 12 drives the sliding column 15 to move upward, and then drives the paddle 13 to move synchronously. In the process of moving, the sliding column 15 is used to abut against the inner wall of the protective shell 3, and then the paddle 13 is pushed to abut and fit with the resistor tube 23. Then, the external withstand voltage test of the power transformer is carried out. As the threaded rod 78 is continuously rotated, the threaded rod 78 drives the sliding frame 11 to move upward from the bottom of the inner cavity of the protective shell 3. The rod 78 will threadably drive the sliding frame 11 to drive the sliding column 15 to move continuously upward, and the sliding column 15 will drive the paddle 13 to move upward synchronously, and the inner wall of the protective shell 3 is intermittently provided with a plurality of protrusions, and then the protrusions can be used to intermittently abut the sliding column 15 to push the paddle 13 to fit and contact with the resistor tube 23. The resistance value of the resistor tube 23 increases from bottom to top, so the resistance value of the contact part between the paddle 13 and the resistor tube 23 will also change. According to the series and parallel principles of resistors, when the contact point between the paddle 13 and the resistor tube 23 changes, the resistance value of the entire circuit will also change accordingly. In the external withstand voltage test of the power transformer, the test device controls the voltage output to the transformer by changing the resistance value of the circuit. When the resistance value increases, the voltage output to the transformer will also decrease accordingly. Conversely, when the resistance value decreases, the voltage output to the transformer will increase, so that the withstand voltage test can be effectively performed on different transformers, thereby solving the above-mentioned problem.

[0044] like Figure 1 , Figure 3 and Figure 5 As shown, a transmission groove 24 is opened inside the upper end surface of the protective shell 3, one end of two threaded rods 78 penetrates the protective shell 3 and is fixedly connected to the inner cavity of the transmission groove 24 with a second bevel gear 76, the second bevel gear 76 is meshingly connected to the first bevel gear 75, and a transmission shaft 74 is fixed inside the first bevel gear 75, and the transmission shaft 74 is rotatably connected to the inner wall of the transmission groove 24.

[0045] like Figure 1 , Figure 3 and Figure 5 As shown, the upper end surface of the protective shell 3 is rotatably connected to a crank 71, one end of the crank 71 passes through the protective shell 3 and is located in the inner cavity of the transmission groove 24 and is fixedly connected to a transmission bevel gear 72, the transmission bevel gear 72 is meshingly connected to a driven bevel gear 73, and the driven bevel gear 73 is fixed to the outside of the transmission shaft 74 for driving the transmission shaft 74 to rotate.

[0046] Specifically, when adjusting the position of the paddle 13 against the resistor tube 23, the crank handle 71 is turned to drive the transmission bevel gear 72 to rotate, and then the transmission bevel gear 72 is meshed with the driven bevel gear 73 to rotate, and at the same time the driven bevel gear 73 drives the transmission shaft 74 to rotate, and drives the two first bevel gears 75 to rotate, and then the first bevel gear 75 is used to mesh with the second bevel gear 76 to rotate, and at the same time drives the threaded rod 78 to rotate, and then the threaded rod 78 drives the sliding frame 11 to move in the inner cavity of the protective shell 3, so that the sliding frame 11 drives the mounting plate 12 to move synchronously, and at the same time the mounting plate 12 drives the sliding column 15 to move upward, and then drives the paddle 13 to move synchronously, so as to adjust the paddle 13 and the resistor. When the surface of the resistor tube 23 is in contact with the pick 13 and the pick is at the bottom of the resistor tube 23, the resistance will increase and the voltage transmitted to the transformer will decrease, and the pick 13 will continue to move upward, and the resistance will gradually decrease, thereby increasing the voltage transmitted to the transformer, and the pick 13 will be at the bottom of the inner cavity of the protective shell 3 in the initial stage, and the voltage transmitted to the transformer will be gradually increased by driving the pick 13 upward, thereby improving the stability of the transformer withstand voltage test, thereby solving the problem that the external withstand voltage test device of the existing transformer is inconvenient to control the voltage transmitted to the transformer, so that when the transformer is subjected to the withstand voltage test, excessive voltage is directly transmitted to the transformer, causing the transformer to be overloaded, causing damage to the transformer or the test device.

[0047] like Figure 3 , Figure 4 and Figure 6 As shown, through slots 16 are provided on both sides of the sliding frame 11, a first spring 17 is fixedly connected to one end surface of the mounting plate 12, and the first spring 17 slides in the inner cavity of the through slot 16, a stop block 14 is fixedly connected to one end of the first spring 17, and the stop block 14 is fixedly connected to one end of the sliding column 15.

[0048] like Figure 1 , Figures 3 to 6 As shown, two wave blocks 22 are symmetrically fixed to the two walls of the inner cavity of the protective shell 3, and the abutment block 14 is slidably connected to the wave block 22, which is used to drive the paddle 13 to abut the resistor tube 23 to perform an external withstand voltage test of the transformer. The protective shell 3 is made of insulating wooden material, and a plurality of cross grooves 18 are evenly opened at the front and rear ends of the protective shell 3, and scale grooves 8 are opened on the front and rear end surfaces of the protective shell 3 on one side of the cross groove 18 to display the size of the voltage adjustment.

[0049] like Figures 3 to 6As shown, a display block 20 is slidably connected to the inner cavity of the cross groove 18, and the display block 20 is located in a semicircular shape at the recessed part of the wave block 22. The display block 20 is located on both sides of the inner cavity of the cross groove 18 and is fixedly connected with connecting blocks 21. One end of the connecting block 21 is fixedly connected to the second spring 19, and one end of the second spring 19 abuts against the inner wall of the cross groove 18, which is used to display the position of the paddle 13 outside the resistor tube 23.

[0050] Specifically, when the transformer is subjected to a withstand voltage test, the sliding frame 11 is driven to move upward from the bottom of the inner cavity of the protective shell 3, and then the sliding frame 11 drives the mounting plate 12 to move synchronously, and at the same time, the mounting plate 12 drives the sliding column 15 to move upward, and then drives the paddle 13 to move synchronously. In the process of the sliding column 15 moving upward, it will drive the block 14 to abut against the convex part of the wave block 22, and then squeeze the first spring 17 to push the sliding column 15 to move. At the same time, the sliding column 15 pushes the paddle 13 to fit and contact with the surface of the resistor tube 23, so as to perform the first stage of the AC withstand voltage test on the transformer. When the sliding frame 11 is continuously driven to move upward, the sliding frame 11 will drive the sliding column 15 to move upward to the concave part of the wave block 22. At this time, the first spring 17 pops up the block 14 to drive the sliding column 15 to reset. At the same time, the sliding column 15 drives the paddle 13 to abut against the resistor The surface of the tube 23 is out of contact, preventing the pick 13 from contacting and rubbing with the surface of the resistor tube 23 for a long time, causing damage to the pick 13 or the resistor tube 23. When the stop block 14 moves to the recessed part of the wave block 22, the stop block 14 will press the display block 20 to move, and the display block 20 drives the connecting block 21 to squeeze the second spring 19 to slide out of the cross groove 18, so that it is convenient for the operator to slide out the display block 20 in the inner cavity of the cross groove 18 and cooperate with the scale groove 8 to observe the position of the pick 13 to release the resistor tube 23, thereby solving the problem that when the existing transformer external withstand voltage test device performs withstand voltage test on transformers of different sizes, it is inconvenient to observe the contact position of the adjustment pick and the resistor tube, resulting in excessive voltage being transmitted to the small transformer, causing the voltage to break through the ball gap of the transformer, resulting in damage to the transformer and the test equipment.

[0051] Embodiment 2

[0052] like Figure 2 , Figure 7 and Figure 8 As shown, a support frame 4 is installed on one side of the protective shell 3, and a slide groove 27 is provided on one side of the support frame 4. A slot 9 is provided on the inner wall of the slide groove 27. A third spring 28 is fixedly connected to the upper wall of the inner cavity of the slide groove 27, and a grounding component 6 is fixedly connected to one end of the third spring 28, wherein the slot 9 is used to receive the grounding component 6.

[0053] like Figure 2 , Figure 7 and Figure 8As shown, the grounding component 6 includes a slider 61 sliding in the inner cavity of the slide groove 27, a grounding column 62 is installed on one side of the lower end of the slider 61, a conductive slide column 69 is fixedly connected to the inner cavity of the slide groove 27, an annular carbon brush 68 is arranged inside the slider 61, and the annular carbon brush 68 is slidably connected to the outside of the conductive slide column 69, and the annular carbon brush 68 is used to transmit the overload voltage to the grounding column 62.

[0054] like Figure 2 , Figure 7 and Figure 8 As shown, grooves 63 are provided at both ends of the slider 61, an elastic member 64 is fixedly connected to the bottom of the inner cavity of the groove 63, an insert block 610 is fixedly connected to one end of the elastic member 64, and the insert block 610 is slidably connected to the inner cavity of the groove 63, and a traction rope 65 is fixedly connected to one end of the insert block 610 in the inner cavity of the groove 63, a handle 67 is fixedly connected to one end of the traction rope 65, and the handle 67 is slidably connected to the inside of the slider 61.

[0055] Specifically, before the transformer is subjected to a withstand voltage test, the handle 67 is held and moved upward, and the handle 67 pulls the traction rope 65 to move synchronously, and the traction rope 65 pulls the plug 610 to slide into the inner cavity of the groove 63 and squeezes the elastic member 64, and then the slider 61 is bounced downward by the third spring 28, and the slider 61 drives the annular carbon brush 68 to slide outside the conductive slide column 69, and the slider 61 drives the grounding column 62 to contact the ground, so that when the electrical equipment leaks or the voltage is too high, the current is conducted to the conductive slide column 69 through the ground wire, and is conducted to the annular carbon brush 68 through the conductive slide column 69, and then is conducted to the ground through the annular carbon brush 68 through the grounding column 62, thereby increasing the safety of the experiment, thereby solving the problem that the grounding column of the existing external withstand voltage test device for the power transformer is usually fixedly installed with the withstand voltage test device, resulting in that when the withstand voltage test device is transported and moved, it is difficult to avoid bumping into the grounding column, causing the grounding column to break or the internal circuit to short-circuit, thereby affecting the conduction efficiency of the grounding column to the overload voltage and causing the safety of the withstand voltage test device.

[0056] like Figure 1 , Figure 2 and Fig. 9 As shown, a pull rod assembly 5 is installed on one side of the upper end surface of the support plate 1, and the pull rod assembly 5 includes a fixed block 51 fixedly connected to one side of the upper end surface of the support plate 1, a rotating groove 52 is opened inside the fixed block 51, and a rotating column 53 is rotatably connected to the inner cavity of the rotating groove 52. Both ends of the rotating column 53 pass through the fixed block 51 and are fixedly connected to a rotating block 54, one end of the rotating block 54 is fixedly connected to a pull rod 55, the rotating column 53 is located outside the inner cavity of the rotating groove 52 and is fixedly connected to a fixed plate 56, both end surfaces of the fixed plate 56 are fixedly connected to torsion springs 57, and the torsion springs 57 are fixedly connected to the inner wall of the rotating groove 52.

[0057] Specifically, when it is necessary to transport the mobile pressure test device, the pull rod 55 is held to drive the rotating block 54 to rotate, and the rotating block 54 drives the rotating column 53 to rotate, and the rotating column 53 drives the fixed plate 56 to rotate, and then the torsion spring 57 is twisted to adjust the angle, and then the pull rod 55 is used to pull the rotating block 54 to drive the rotating column 53 to move, and the rotating column 53 drives the support plate 1 to move by the fixed block 51, thereby driving the pressure test device to be transported and moved, thereby improving the convenience of the pressure test device when used, and after transporting and moving, the pull rod 55 is released to twist the fixed plate 56 to rotate and reset through the torsion spring 57, and the fixed plate 56 drives the rotating column 53 to rotate and reset, and the rotating column 53 drives the rotating block 54 to rotate and reset, and then drives the pull rod 55 to rotate and reset, thereby facilitating the automatic storage and reset of the pull rod 55, thereby improving the convenience of using the pressure test device, and solving the problem that the existing external pressure test device of the power transformer is large in size and is usually transported and moved by a trailer when used, resulting in inconvenience in use.

[0058] Working principle: when adjusting the position of the paddle 13 against the resistor tube 23, the crank 71 is turned to drive the transmission bevel gear 72 to rotate, and then the transmission bevel gear 72 is meshed with the driven bevel gear 73 to rotate, and at the same time, the driven bevel gear 73 drives the transmission shaft 74 to rotate, and drives the two first bevel gears 75 to rotate, and then the first bevel gear 75 is used to mesh with the second bevel gear 76 to rotate, and at the same time drives the threaded rod 78 to rotate, and then the threaded rod 78 threadedly drives the sliding frame 11 to move in the inner cavity of the protective shell 3, so that the sliding frame 11 drives the mounting plate 12 to move synchronously. At the same time, the mounting plate 12 drives the slide column 15 to move upward, and then drives the paddle 13 to move synchronously, so as to adjust the position where the paddle 13 is in contact with the surface of the resistor tube 23. When the paddle 13 is located at the bottom of the resistor tube 23, the resistance will increase and the voltage transmitted to the transformer will decrease. When the paddle 13 continues to move upward, the resistance will gradually decrease, thereby increasing the voltage transmitted to the transformer. In the initial stage, the paddle 13 will be at the bottom of the inner cavity of the protective shell 3, and the voltage transmitted to the transformer will be gradually increased by driving the paddle 13 upward, thereby improving the stability of the transformer withstand voltage test.

[0059] When the transformer is subjected to a withstand voltage test, the sliding frame 11 is driven to move upward from the bottom of the inner cavity of the protective shell 3, and then the sliding frame 11 drives the mounting plate 12 to move synchronously, and at the same time, the mounting plate 12 drives the sliding column 15 to move upward, and then drives the paddle 13 to move synchronously, and in the process of the sliding column 15 moving upward, it will drive the abutment block 14 to abut against the raised part of the wave block 22, and then squeeze the first spring 17 to push the sliding column 15 to move, and at the same time, the sliding column 15 pushes the paddle 13 to fit and contact with the surface of the resistor tube 23, so as to perform the first stage of the AC withstand voltage test on the transformer, and when the sliding frame 11 is continuously driven to move upward, the sliding frame 11 will drive the sliding column 15 to move upward When the first spring 17 bounces up the stopper 14 and drives the slide post 15 to reset, the slide post 15 drives the paddle 13 to disengage from the surface of the resistor tube 23, so as to prevent the paddle 13 from contacting and rubbing with the surface of the resistor tube 23 for a long time, thereby damaging the paddle 13 or the resistor tube 23. When the stopper 14 moves to the concave part of the wave block 22, the stopper 14 presses the display block 20 to move, and the display block 20 drives the connecting block 21 to squeeze the second spring 19 to slide out of the cross slot 18, so as to facilitate the operator to observe the position of the paddle 13 to release the resistor tube 23 by sliding the display block 20 in the inner cavity of the cross slot 18 and cooperating with the scale slot 8.

[0060] Before conducting a withstand voltage test on the transformer, the handle 67 is held and moved upward, and the handle 67 pulls the traction rope 65 to move synchronously. At the same time, the traction rope 65 pulls the plug 610 to slide into the inner cavity of the groove 63 and squeezes the elastic member 64. Then, the third spring 28 is used to bounce the slider 61 downward, and the slider 61 drives the annular carbon brush 68 to slide outside the conductive slide 69. At the same time, the slider 61 drives the grounding column 62 to contact the ground, so that when the electrical equipment leaks or the voltage is too high, the current is conducted to the conductive slide 69 through the ground wire, and at the same time, it is conducted to the annular carbon brush 68 through the conductive slide 69, and then conducted to the ground through the annular carbon brush 68 using the grounding column 62, thereby increasing the safety of the experiment.

[0061] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An externally applied voltage withstand test device for a power transformer, characterized in that: It comprises a support plate (1), the lower end surface of the support plate (1) is provided with universal wheels (10) at four corners, the upper end surface of the support plate (1) is provided with a base (2), the upper end surface of the base (2) is fixedly connected with a limit seat (25), a resistor tube (23) is provided in the inner cavity of the limit seat (25), a protective shell (3) is provided outside the resistor tube (23), the upper end surface of the protective shell (3) is provided with fastening bolts (26) at four corners for rotation connection, and the fastening bolts (26) are threadedly connected to the base (2), and an adjustment component (7) is provided outside the resistor tube (23); The adjustment assembly (7) includes two threaded rods (78) rotatably connected to the inner cavity of the protective shell (3), and the two threaded rods (78) are externally threadedly connected to a sliding frame (11) for driving the sliding frame (11) to move up and down in the inner cavity of the protective shell (3) to adjust the position; The inner wall of the sliding frame (11) is symmetrically mounted with two mounting plates (12), and the two mounting plates (12) are both slidably connected with a sliding column (15), and one end of the sliding column (15) is fixedly connected with a paddle (13) for driving the sliding column (15) to drive the paddle (13) to fit and contact the resistor tube (23).

2. The device for testing the externally applied voltage of a power transformer according to claim 1, characterized in that: A transmission groove (24) is provided inside the upper end surface of the protective shell (3); one end of the two threaded rods (78) penetrates the protective shell (3) and is located in the inner cavity of the transmission groove (24) and is fixedly connected to a second bevel gear (76); the second bevel gear (76) is meshingly connected to the first bevel gear (75); a transmission shaft (74) is fixedly connected inside the first bevel gear (75); and the transmission shaft (74) is rotatably connected to the inner wall of the transmission groove (24).

3. The device for testing the externally applied voltage of a power transformer according to claim 2, characterized in that: The upper end surface of the protective shell (3) is rotatably connected to a crank (71); one end of the crank (71) passes through the protective shell (3) and is located in the inner cavity of the transmission groove (24) and is fixedly connected to a transmission bevel gear (72); the transmission bevel gear (72) is meshingly connected to a driven bevel gear (73), and the driven bevel gear (73) is fixedly connected to the outside of the transmission shaft (74) for driving the transmission shaft (74) to rotate.

4. The device for testing the externally applied voltage of a power transformer according to claim 1, characterized in that: Through slots (16) are provided on both sides of the sliding frame (11); a first spring (17) is fixedly connected to one end surface of the mounting plate (12), and the first spring (17) slides in the inner cavity of the through slot (16); a stop block (14) is fixedly connected to one end of the first spring (17), and the stop block (14) is fixedly connected to one end of the sliding column (15).

5. The device for testing the externally applied voltage of a power transformer according to claim 4, characterized in that: Two wave blocks (22) are symmetrically fixedly connected to the inner walls of the protective shell (3), and the abutment block (14) is slidably connected to the wave block (22) for driving the paddle (13) to abut the resistor tube (23) to perform an external withstand voltage test on the transformer. The protective shell (3) is made of insulating wood material. A plurality of cross grooves (18) are evenly arranged at the front and rear ends of the protective shell (3), and scale grooves (8) are arranged on the front and rear end surfaces of the protective shell (3) on one side of the cross groove (18) for displaying the size of the voltage adjustment.

6. The device for testing the externally applied voltage of a power transformer according to claim 5, characterized in that: The inner cavity of the cross groove (18) is slidably connected with a display block (20), and the display block (20) is located in a concave portion of the wave block (22) and is arranged in a semicircular shape. The display block (20) is located in the inner cavity of the cross groove (18) and is fixedly connected with connecting blocks (21) on both sides thereof. One end of the connecting block (21) is fixedly connected with a second spring (19), and one end of the second spring (19) abuts against the inner wall of the cross groove (18) to display the position of the pick (13) outside the resistor tube (23).

7. The device for testing an externally applied voltage resistance of a power transformer according to claim 1, characterized in that: A support frame (4) is installed on one side of the protective shell (3), and a slide groove (27) is formed on one side of the support frame (4). A slot (9) is provided on the inner wall of the slide groove (27), and a third spring (28) is fixedly connected to the upper wall of the inner cavity of the slide groove (27), and a grounding component (6) is fixedly connected to one end of the third spring (28), wherein the slot (9) is used to receive the grounding component (6).

8. The device for testing the externally applied voltage of a power transformer according to claim 7, characterized in that: The grounding component (6) comprises a slider (61) sliding in the inner cavity of a slide groove (27), a grounding column (62) is installed on one side of the lower end of the slider (61), a conductive slide column (69) is fixedly connected to the inner cavity of the slide groove (27), an annular carbon brush (68) is arranged inside the slider (61), and the annular carbon brush (68) is slidably connected to the outside of the conductive slide column (69), and the annular carbon brush (68) is used to transmit an overload voltage to the grounding column (62).

9. The device for testing the externally applied voltage of a power transformer according to claim 8, characterized in that: Both ends of the slider (61) are provided with grooves (63), the bottom of the inner cavity of the groove (63) is fixedly connected with an elastic member (64), one end of the elastic member (64) is fixedly connected with an insert block (610), and the insert block (610) is slidably connected to the inner cavity of the groove (63), one end of the insert block (610) located in the inner cavity of the groove (63) is fixedly connected with a traction rope (65), one end of the traction rope (65) is fixedly connected with a handle (67), and the handle (67) is slidably connected to the inside of the slider (61).

10. The device for testing the externally applied voltage of a power transformer according to claim 1, characterized in that: A pull rod assembly (5) is installed on one side of the upper end surface of the support plate (1), and the pull rod assembly (5) includes a fixed block (51) fixedly connected to one side of the upper end surface of the support plate (1), a rotating groove (52) is opened inside the fixed block (51), and a rotating column (53) is rotatably connected to the inner cavity of the rotating groove (52), and both ends of the rotating column (53) pass through the fixed block (51) and are fixedly connected to a rotating block (54), and one end of the rotating block (54) is fixedly connected to a pull rod (55), and the rotating column (53) is located outside the inner cavity of the rotating groove (52) and is fixedly connected to a fixed disk (56), and both end surfaces of the fixed disk (56) are fixedly connected to torsion springs (57), and the torsion springs (57) are fixedly connected to the inner wall of the rotating groove (52).

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