Low-voltage current transformer

Abstract

The invention belongs to the technical field of current transformers, and particularly relates to a low-voltage current transformer which comprises a transport frame, a transformer body is arranged in the transport frame, a fixed plate is fixedly mounted in the transport frame through a connecting rod, a rotating rod is rotatably mounted on the fixed plate in a penetrating manner, and a knob is arranged on the rotating rod; fixing mechanisms are arranged on the two sides of the fixing plate, and the fixing mechanisms are used for clamping and fixing the two sides of the mutual inductor body in multiple positions; a locking mechanism is arranged in the conveying frame and used for preventing the mutual inductor body from loosening in the conveying process. By arranging the fixing mechanism, the mutual inductor body can be clamped and fixed in multiple positions from the two sides of the center of the mutual inductor body, position deviation of the mutual inductor body in all directions is effectively prevented, and the stability of the mutual inductor body during transportation is improved; and meanwhile, the locking mechanism is arranged, so that the mutual inductor body is automatically locked when the conveying frame is closed by the baffle.

Description

Technical Field

[0001] The invention belongs to the technical field of current transformers, and in particular relates to a low-voltage current transformer. Background Art

[0002] A current transformer is a precision instrument used to convert large currents in AC circuits into a small current of a certain proportion. It is usually used for current measurement and relay protection.

[0003] During the use and transportation of the current transformer, it is necessary to carry out anti-collision treatment on the current transformer. After searching, the patent document with publication number CN114664517 B discloses a current transformer, including a transformer body, which is arranged in a moving assembly. The moving assembly includes a moving box, a connecting assembly and a moving cover. The moving box is provided with a placement opening, and the moving cover is movably connected to one end of the moving box with the placement opening through the connecting assembly.

[0004] The above-mentioned current transformer can prevent external impact during transportation and avoid damage to the current transformer. However, the following technical problems still exist: 1. When fixing the current transformer, the fixing effect of the current transformer is poor, resulting in poor stability of the current transformer during transportation. At the same time, the current transformer needs to be fixed from different directions, which is very cumbersome. 2. After fixing the current transformer, it is necessary to lock the current transformer to prevent it from loosening during transportation, which increases the workload of the staff; 3. When transporting the current transformer, the air convection speed in the moving box is slow, which makes it difficult for the current transformer to dissipate heat and easily cause overheating and damage. Summary of the invention

[0005] The purpose of the present invention is to provide a low-voltage current transformer that can clamp and fix the transformer body in all directions, improve the stability of the transformer, and automatically lock the transformer in order to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: Low voltage current transformer, including: A transport frame, wherein a transformer body is arranged inside the transport frame, a fixing plate is fixedly installed in the transport frame through a connecting rod, a rotating rod is rotatably installed through the fixing plate, and a knob is arranged on the rotating rod; Both sides of the fixing plate are provided with fixing mechanisms, and the fixing mechanisms are used to clamp and fix the two sides of the transformer body at multiple positions; A locking mechanism is provided inside the transport frame, and the locking mechanism is used to prevent the transformer body from loosening during transportation.

[0007] Preferably, the fixing mechanism includes a driving gear, a plurality of screw rods, a plurality of transmission gears, a plurality of moving blocks, a plurality of racks, a plurality of mounting blocks, a plurality of rotating shafts, a plurality of first gears, a plurality of fixed blocks and a plurality of fixed abutment plates. The driving gear is mounted on the rotating rod. A plurality of screw rods are rotatably mounted on the side wall of the fixed plate. Each of the screw rods is provided with a transmission gear, and each of the transmission gears is meshed with the driving gear. A moving block is threadedly mounted on each of the screw rods, and each of the moving blocks is provided with a rack. A plurality of mounting blocks are provided on the fixed plate, and each of the mounting blocks is rotatably mounted with a rotating shaft. Each of the rotating shafts is provided with a first gear, and each of the first gears is meshed with the rack at the corresponding position. A fixed abutment plate is mounted on each of the rotating shafts via a fixed block.

[0008] Preferably, the locking mechanism comprises two support plates, two lifting rods, two locking friction plates, a locking column, two trapezoidal guide plates, two slide grooves, two L-shaped plates, a plurality of first springs, two first hinge seats, two guide rollers, a baffle and two heat dissipation mechanisms. The two support plates are arranged in the transport frame, and a lifting rod is slidably installed on each of the support plates. A locking friction plate is arranged at the bottom of each of the lifting rods, a locking column is arranged on the rotating rod, and a trapezoidal guide plate is arranged above each of the lifting rods. Slide grooves are provided on the inner walls on both sides, and an L-shaped plate is slidably installed in each of the slide grooves. Each of the L-shaped plates is elastically connected to the inner wall of the slide groove through a plurality of first springs. A first hinge seat is provided under each of the L-shaped plates, and a guide roller is hinged on each of the first hinge seats. The two guide rollers roll in contact with the two trapezoidal guide plates. Baffles are installed on the parts of the two L-shaped plates extending outside the transport frame, and a heat dissipation mechanism is provided on each of the trapezoidal guide plates. The heat dissipation mechanism is used to ventilate and dissipate heat from the transformer body.

[0009] Preferably, the heat dissipation mechanism includes a placement slot, a swinging guide plate, a liquid storage chamber, an infusion channel, a lifting block, a push rod, an arc frame, a piston block, a second hinge seat, a swing rod, an arc rod, a counterweight ball and a second spring. The placement slot is opened above the trapezoidal guide plate, and a swinging guide plate is rotatably installed in the placement slot. A liquid storage chamber is provided below the trapezoidal guide plate, and an infusion channel is provided between the liquid storage chamber and the placement slot. A lifting block is sealingly and slidably installed in the infusion channel, a push rod is provided above the lifting block, and an arc frame is provided below the liquid storage chamber. A piston block is sealingly and slidably installed in the arc frame, a swing rod is installed below the trapezoidal guide plate through the second hinge seat, the swing rod is connected to the piston block through the arc rod, a counterweight ball is installed at the bottom of the swing rod, and the swing rod is elastically connected to the lower wall of the trapezoidal guide plate through the second spring.

[0010] Preferably, a limiting strip is provided on the side wall of the fixed plate, and the moving block is slidably mounted on the limiting strip.

[0011] Preferably, when the guide roller moves onto the trapezoidal guide plate, the locking friction plate approaches the locking column and is in close contact with the locking column.

[0012] Preferably, the liquid storage chamber, the liquid infusion channel and the arc-shaped frame are filled with hydraulic oil.

[0013] Compared with the existing technology, the advantages of this low voltage current transformer are: 1. The present invention sets a fixing mechanism. Before transportation, the transformer body is placed in the transport frame, and the rotating rod is rotated by a knob. The driving gear and the transmission gears are further used to drive the plurality of screws to rotate synchronously, so that the plurality of moving blocks on both sides of the fixed plate are close to the fixed plate, and the plurality of first gears are further driven to rotate under the action of the rack, so that the plurality of fixed abutment plates on both sides are swung close to the transformer body, and the transformer body is clamped and fixed in multiple positions from both sides of the center of the transformer body, which effectively prevents the position deviation of the transformer body in various directions, improves the stability of the transformer body during transportation, and avoids the transformer body from being damaged by collision. At the same time, the fixing operation of the transformer body is very convenient, and only the rotating rod needs to be driven to rotate, thereby improving the convenience of operation.

[0014] 2. The present invention sets a locking mechanism. After the rotating rod rotates and the transformer body is fixed, it is necessary to loosen the baffle and close the transport frame. During this process, the baffle approaches the transport frame under the action of the first spring, and the movement of the L-shaped plate will cause the guide roller to translate to above the trapezoidal guide plate, further squeezing and pushing the trapezoidal guide plate to move downward, and drive the locking friction plate to be tightly attached to the locking column through the lifting rod, so as to lock and fix the locking column and the rotating rod, so as to prevent the rotating rod from rotating automatically due to shaking during the process of transporting the transformer body, causing the fixed plate to loosen, and automatically realize the locking process of the transformer body.

[0015] 3. The present invention sets a heat dissipation mechanism. During the transportation of the mutual inductor, the shaking of the transport frame will drive the counterweight ball to swing intermittently, and intermittently restore the initial state under the elastic force of the second spring, driving the rocker arm to swing back and forth, causing the piston block to move back and forth in the arc frame, and reciprocatingly transporting the hydraulic oil in the arc frame to the liquid storage chamber and the infusion channel, causing the lifting block in the infusion channel to perform reciprocating vertical displacement, and further driving the swing guide plate to swing back and forth upward through the support rod, pushing the guide roller back and forth, driving the baffle to perform reciprocating horizontal displacement, increasing the air convection between the transport frame and the outside world, ensuring the heat dissipation and ventilation of the mutual inductor body, and avoiding overheating and damage of the mutual inductor body during transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional structural schematic diagram of a low-voltage current transformer provided by the present invention; Figure 2 is a cross-sectional view of a low-voltage current transformer provided by the present invention; Figure 3 yes Figure 2 The enlarged view of point A in the middle; Figure 4 It is a schematic diagram of the local structure of the fixing mechanism in the low-voltage current transformer provided by the present invention; Figure 5 yes Figure 4 The enlarged view of point B in the middle; Figure 6 It is a partial structural schematic diagram of the heat dissipation mechanism in the low-voltage current transformer provided by the present invention; Figure 7 yes Figure 6 Enlarged view of point C in the middle.

[0017] In the figure, 1, transport frame; 11, transformer body; 12, fixing plate; 13, rotating rod; 14, knob; 2, fixing mechanism; 21, driving gear; 22, screw; 23, transmission gear; 24, moving block; 25, rack; 26, mounting block; 27, rotating shaft; 28, first gear; 29, fixing block; 210, fixing plate; 3, locking mechanism; 31, supporting plate; 32, lifting rod; 33, locking friction plate; 34, locking column; 35, trapezoidal guide To plate; 36, slide groove; 37, L-shaped plate; 38, first spring; 39, first hinge seat; 310, guide roller; 311, baffle; 4, heat dissipation mechanism; 41, placement groove; 42, swing guide plate; 43, liquid storage chamber; 44, infusion channel; 45, lifting block; 46, push rod; 47, arc frame; 48, piston block; 49, second hinge seat; 410, rocker arm; 411, arc rod; 412, counterweight ball; 413, second spring; 5, limit strip. DETAILED DESCRIPTION

[0018] The following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0019] like Figure 1-Figure 7 As shown, the low voltage current transformer comprises: A transport frame 1, wherein a transformer body 11 is arranged inside the transport frame 1, a fixing plate 12 is fixedly installed in the transport frame 1 through a connecting rod, a rotating rod 13 is rotatably installed through the fixing plate 12, and a knob 14 is arranged on the rotating rod 13; Both sides of the fixing plate 12 are provided with fixing mechanisms 2, and the fixing mechanisms 2 are used to clamp and fix both sides of the transformer body 11 at multiple positions; A locking mechanism 3 is provided inside the transport frame 1 , and the locking mechanism 3 is used to prevent the transformer body 11 from loosening during transportation.

[0020] The fixing mechanism 2 includes a driving gear 21, a plurality of screw rods 22, a plurality of transmission gears 23, a plurality of moving blocks 24, a plurality of racks 25, a plurality of mounting blocks 26, a plurality of rotating shafts 27, a plurality of first gears 28, a plurality of fixing blocks 29 and a plurality of fixing plates 210. The driving gear 21 is mounted on the rotating rod 13. A plurality of screw rods 22 are rotatably mounted on the side wall of the fixing plate 12. A transmission gear 23 is provided on each screw rod 22. Each transmission gear 23 is meshed with the driving gear 21. A moving block 24 is threadedly mounted on each screw rod 22. Each moving block 24 is provided with a rack 25. A plurality of mounting blocks 26 are provided on the fixing plate 12. A rotating shaft 27 is rotatably mounted on each mounting block 26. Each rotating shaft 27 is provided with a first gear 28. Each first gear 28 is meshed with the rack 25 at the corresponding position. A fixing plate 210 is mounted on each rotating shaft 27 through a fixing block 29.

[0021] Among them, a limit bar 5 is provided on the side wall of the fixed plate 12, and the moving block 24 is slidably installed on the limit bar 5. The limit bar 5 limits the moving block 24, so that the moving block 24 can only move horizontally when the screw rod 22 rotates.

[0022] In view of the poor fixing effect of the transformer in the prior art, which leads to poor stability of the transformer during transportation, and the need to fix the current transformer from different directions, which is very cumbersome to operate, the present invention provides a fixing mechanism 2. Before transportation, the transformer body 11 is placed in the transport frame 1, and the rotating rod 13 is rotated by the knob 14. The driving gear 21 and the plurality of transmission gears 23 further drive the plurality of screws 22 to rotate synchronously, so that the plurality of moving blocks 24 on both sides of the fixed plate 12 are close to the fixed plate 12, and further drive the plurality of first gears 28 to rotate under the action of the rack 25, so that the plurality of fixed abutment plates 210 on both sides are swung close to the transformer body 11, and the transformer body 11 is clamped and fixed in multiple positions from both sides of the center of the transformer body 11, effectively preventing the position deviation of the transformer body 11 in all directions, improving the stability of the transformer body 11 during transportation, and preventing the transformer body 11 from being damaged by collision. At the same time, the fixing operation of the transformer body 11 is very convenient, and it is only necessary to drive the rotating rod 13 to rotate, thereby improving the convenience of operation.

[0023] The locking mechanism 3 includes two support plates 31, two lifting rods 32, two locking friction plates 33, a locking column 34, two trapezoidal guide plates 35, two slide grooves 36, two L-shaped plates 37, a plurality of first springs 38, two first hinge seats 39, two guide rollers 310, a baffle 311 and two heat dissipation mechanisms 4. The two support plates 31 are arranged in the transport frame 1, and a lifting rod 32 is slidably installed on each support plate 31. A locking friction plate 33 is provided at the bottom of each lifting rod 32, a locking column 34 is provided on the rotating rod 13, and a trapezoidal guide plate 35 is provided above each lifting rod 32. Slide grooves 36 are provided on the inner walls on both sides of the transport frame 1, and an L-shaped plate 37 is slidably installed in each slide groove 36. Each L-shaped plate 37 is elastically connected to the inner wall of the slide groove 36 through a plurality of first springs 38. A first hinge seat 39 is provided below each L-shaped plate 37, and a guide roller 310 is hinged on each first hinge seat 39. The two guide rollers 310 roll in contact with the two trapezoidal guide plates 35. The parts of the two L-shaped plates 37 extending outside the transport frame 1 are installed with baffles 311. Each trapezoidal guide plate 35 is provided with a heat dissipation mechanism 4, and the heat dissipation mechanism 4 is used to ventilate and dissipate heat for the transformer body 11.

[0024] Among them, when the guide roller 310 moves to the trapezoidal guide plate 35, the locking friction plate 33 is close to the locking column 34 and is tightly attached to the locking column 34. When the locking friction plate 33 is tightly attached to the locking column 34, the locking column 34 is not easy to rotate due to the large friction between the locking friction plate 33 and the locking column 34, which further makes the rotating rod 13 difficult to rotate.

[0025] In view of the problem that the prior art needs to lock the current transformer separately to prevent the current transformer from loosening during transportation, which increases the workload of the staff, the present invention provides a locking mechanism 3. After the rotating rod 13 rotates and the transformer body 11 is fixed, the baffle 311 needs to be loosened to close the transport frame 1. During this process, the baffle 311 approaches the transport frame 1 under the action of the first spring 38, and the movement of the L-shaped plate 37 will cause the guide roller 310 to translate to above the trapezoidal guide plate 35, further squeezing and pushing the trapezoidal guide plate 35 to move downward, and drive the locking friction plate 33 to be tightly attached to the locking column 34 through the lifting rod 32, so as to lock and fix the locking column 34 and the rotating rod 13, so as to prevent the transport frame 1 from rotating by itself due to shaking during the transportation of the transformer body 11, causing the fixed plate 210 to loosen, thereby automatically realizing the locking process of the transformer body 11.

[0026] The heat dissipation mechanism 4 includes a placement groove 41, a swing guide plate 42, a liquid storage chamber 43, an infusion channel 44, a lifting block 45, a push rod 46, an arc frame 47, a piston block 48, a second hinge seat 49, a swing rod 410, an arc rod 411, a weight ball 412 and a second spring 413. The placement groove 41 is opened above the trapezoidal guide plate 35, and the swing guide plate 42 is rotatably installed in the placement groove 41. The liquid storage chamber 43 is provided below the trapezoidal guide plate 35, and an infusion channel 44 is provided between the liquid storage chamber 43 and the placement groove 41. 4. A lifting block 45 is installed in a sealing and sliding manner in the infusion channel 44, a stop rod 46 is provided above the lifting block 45, an arc frame 47 is provided below the liquid storage chamber 43, a piston block 48 is installed in a sealing and sliding manner in the arc frame 47, a swing rod 410 is installed below the trapezoidal guide plate 35 through a second hinge seat 49, the swing rod 410 is connected to the piston block 48 through an arc rod 411, a weight ball 412 is installed at the bottom of the swing rod 410, and the swing rod 410 is elastically connected to the lower wall of the trapezoidal guide plate 35 through a second spring 413.

[0027] The liquid storage chamber 43 , the liquid infusion channel 44 and the arc frame 47 are filled with hydraulic oil.

[0028] In view of the problem that the air convection speed in the moving box in the prior art is slow, which makes it difficult for the current transformer to dissipate heat and is prone to overheating and damage, the present invention provides a heat dissipation mechanism 4. During the transportation of the transformer, the shaking of the transport frame 1 will drive the counterweight ball 412 to swing intermittently, and intermittently restore the initial state under the elastic force of the second spring 413, thereby driving the swing rod 410 to swing back and forth, and driving the piston block 48 to move back and forth in the arc frame 47 through the arc rod 411, and reciprocatingly transporting the hydraulic oil in the arc frame 47 to the liquid storage chamber 43 and the infusion channel 44, so that the lifting block 45 in the infusion channel 44 performs reciprocating vertical displacement, and further through the resistance The rod 46 drives the swing guide plate 42 to swing upward reciprocatingly, pushing the guide roller 310 reciprocatingly. When the swing guide plate 42 swings upward and tilts, the guide roller 310 will move along the inclined surface of the swing guide plate 42, further causing the L-shaped plate 37 to translate, so that the baffle 311 can be moved away from the transport frame 1. When the swing guide plate 42 swings downward to restore the horizontal level, the guide roller 310 can move back to the initial position and the baffle 311 can be close to the transport frame 1. The reciprocating horizontal displacement of the baffle 311 increases the air convection between the transport frame 1 and the outside world, ensuring the heat dissipation and ventilation of the transformer body 11, and avoiding overheating and damage of the transformer body 11 during transportation.

[0029] The present invention can be explained by the following operation mode: Before transportation, the transformer body 11 is placed in the transport frame 1, and the rotating rod 13 is rotated by the knob 14, and further the driving gear 21 and the plurality of transmission gears 23 drive the plurality of screws 22 to rotate synchronously, so that the plurality of moving blocks 24 on both sides of the fixed plate 12 are close to the fixed plate 12, and further the plurality of first gears 28 are driven to rotate under the action of the rack 25, so that the plurality of fixed abutment plates 210 on both sides are swung close to the transformer body 11, and the fixed abutment plates 210 arranged on both sides can clamp the transformer body 11 from both sides at the same time, and the fixed abutment plates 210 on both sides are made to present a concave shape in the middle, so that the transformer body 11 can be stuck between the fixed abutment plates 210 on both sides, and in addition, the plurality of fixed abutment plates 210 can be arranged, so that the transformer body 11 can be fully clamped and fixed from multiple angles at the same time, thereby improving the stability of the transformer body 11 and the convenience of operation; Release the baffle 311 and close the transport frame 1. During this process, the baffle 311 is moved closer to the transport frame 1 under the action of the first spring 38. The movement of the L-shaped plate 37 causes the guide roller 310 to translate to above the trapezoidal guide plate 35, further squeezing and pushing the trapezoidal guide plate 35 to move downward, and driving the locking friction plate 33 to be tightly attached to the locking column 34 through the lifting rod 32, locking and fixing the locking column 34 and the rotating rod 13, and automatically realizing the locking process of the transformer body 11; During the transportation of the mutual inductor, the shaking of the transport frame 1 will drive the counterweight ball 412 to swing intermittently, and intermittently restore the initial state under the elastic force of the second spring 413, thereby driving the swing rod 410 to swing back and forth, and driving the piston block 48 to move back and forth in the arc frame 47 through the arc rod 411, and reciprocatingly transporting the hydraulic oil in the arc frame 47 to the liquid storage chamber 43 and the infusion channel 44, so that the lifting block 45 in the infusion channel 44 performs reciprocating vertical displacement, and further drives the swing guide plate 42 to swing back and forth upward through the support rod 46, and pushes the guide roller 310 back and forth, driving the baffle 311 to reciprocate horizontal displacement, thereby increasing the air convection between the transport frame 1 and the outside world, and avoiding overheating and damage of the mutual inductor body 11 during transportation.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Low voltage current transformer, characterized in that: include: A transport frame (1), wherein a transformer body (11) is provided inside the transport frame (1), a fixing plate (12) is fixedly installed inside the transport frame (1) via a connecting rod, a rotating rod (13) is rotatably installed through the fixing plate (12), and a knob (14) is provided on the rotating rod (13); Both sides of the fixing plate (12) are provided with fixing mechanisms (2), and the fixing mechanisms (2) are used to clamp and fix both sides of the transformer body (11) at multiple positions; A locking mechanism (3) is provided inside the transport frame (1), and the locking mechanism (3) is used to prevent the transformer body (11) from loosening during transportation.

2. The low voltage current transformer according to claim 1, characterized in that: The fixing mechanism (2) comprises a driving gear (21), a plurality of screw rods (22), a plurality of transmission gears (23), a plurality of moving blocks (24), a plurality of racks (25), a plurality of mounting blocks (26), a plurality of rotating shafts (27), a plurality of first gears (28), a plurality of fixing blocks (29) and a plurality of fixing abutment plates (210), wherein the driving gear (21) is mounted on the rotating rod (13), a plurality of screw rods (22) are rotatably mounted on the side wall of the fixing plate (12), each of the screw rods (22) is provided with a transmission gear (23), and each of the transmission gears (23) is provided with a plurality of screw rods (22). (23) are meshed with the driving gear (21), each of the screw rods (22) is threadedly mounted with a moving block (24), each of the moving blocks (24) is provided with a rack (25), a plurality of mounting blocks (26) are provided on the fixed plate (12), each of the mounting blocks (26) is rotatably mounted with a rotating shaft (27), each of the rotating shafts (27) is provided with a first gear (28), each of the first gears (28) is meshed with the rack (25) at a corresponding position, and each of the rotating shafts (27) is mounted with a fixed abutment plate (210) via a fixed block (29).

3. The low voltage current transformer according to claim 1, characterized in that: The locking mechanism (3) comprises two support plates (31), two lifting rods (32), two locking friction plates (33), a locking column (34), two trapezoidal guide plates (35), two slide grooves (36), two L-shaped plates (37), a plurality of first springs (38), two first hinge seats (39), two guide rollers (310), a baffle (311) and two heat dissipation mechanisms (4). The two support plates (31) are arranged in the transport frame (1). A lifting rod (32) is slidably installed on each support plate (31). A locking friction plate (33) is provided at the bottom of each lifting rod (32). The rotating rod (13) is provided with a locking column (34). A trapezoidal guide plate (35) is provided above each lifting rod (32). Slide grooves (36) are provided on the inner walls of both sides of the transport frame (1), and an L-shaped plate (37) is slidably installed in each of the slide grooves (36). Each of the L-shaped plates (37) is elastically connected to the inner wall of the slide groove (36) via a plurality of first springs (38). A first hinge seat (39) is provided below each of the L-shaped plates (37), and a guide roller (310) is hingedly connected to each of the first hinge seats (39). The two guide rollers (310) roll in contact with the two trapezoidal guide plates (35). A baffle (311) is installed on the portion of the two L-shaped plates (37) extending outside the transport frame (1), and a heat dissipation mechanism (4) is provided on each of the trapezoidal guide plates (35). The heat dissipation mechanism (4) is used to ventilate and dissipate heat for the transformer body (11).

4. The low voltage current transformer according to claim 3, characterized in that: The heat dissipation mechanism (4) comprises a placement groove (41), a swing guide plate (42), a liquid storage chamber (43), an infusion channel (44), a lifting block (45), a support rod (46), an arc frame (47), a piston block (48), a second hinge seat (49), a swing rod (410), an arc rod (411), a weighted ball (412) and a second spring (413). The placement groove (41) is opened above the trapezoidal guide plate (35). The swing guide plate (42) is rotatably installed in the placement groove (41). The liquid storage chamber (43) is provided below the trapezoidal guide plate (35). The infusion channel (44) is provided between the liquid storage chamber (43) and the placement groove (41). 4), a lifting block (45) is installed in a sealing and slidable manner in the infusion channel (44), a support rod (46) is provided above the lifting block (45), an arc frame (47) is provided below the liquid storage chamber (43), a piston block (48) is installed in a sealing and slidable manner in the arc frame (47), a swing rod (410) is installed below the trapezoidal guide plate (35) through a second hinge seat (49), the swing rod (410) is connected to the piston block (48) through an arc rod (411), a counterweight ball (412) is installed at the bottom of the swing rod (410), and the swing rod (410) is elastically connected to the lower wall of the trapezoidal guide plate (35) through a second spring (413).

5. The low voltage current transformer according to claim 2, characterized in that: A limiting strip (5) is provided on the side wall of the fixed plate (12), and the moving block (24) is slidably mounted on the limiting strip (5).

6. The low voltage current transformer according to claim 3, characterized in that: When the guide roller (310) moves onto the trapezoidal guide plate (35), the locking friction plate (33) approaches the locking column (34) and is in close contact with the locking column (34).

7. The low voltage current transformer according to claim 4, characterized in that: The liquid storage chamber (43), the liquid infusion channel (44) and the arc-shaped frame (47) are filled with hydraulic oil.

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