Portable ct polarity testing device

Abstract

This invention relates to the field of current polarity detection technology, specifically to a portable CT polarity testing device, comprising a tester, a lead wire, a handheld lever, and a clamping mechanism; the lead wire connects the tester and the clamping mechanism; the clamping mechanism, mounted on the handheld lever, is used to clamp external device terminals and includes a fixing part, a turntable, clamping rods, and a pull rope; the fixing part is fixed to the handheld lever; there are two turntables, coaxial and rotating about an axis perpendicular to the handheld lever, mounted on the fixing part, and always rotating in opposite directions; by arranging four clamping rods around the turntable, four clamping intervals are defined. During use, a suitable clamping interval can be selected according to the position of the device terminal, and the pull rope drives the turntable to rotate, causing the clamping rods to swing for clamping. This device can adapt to environments with complex circuits and where direct human operation is difficult, increasing the convenience of clamping.

Description

Technical Field

[0001] This invention relates to the field of current polarity detection technology, and more specifically to a portable CT polarity testing device. Background Technology

[0002] Portable current transformer (CT) polarity testing devices are primarily used to check the polarity of current transformers (CTs) to ensure correct wiring direction. This is crucial for the safe operation of power systems and the normal functioning of equipment, especially during relay protection and metering, where correct polarity ensures signal accuracy. In use, the testing terminals of the device are connected to the output terminal of the secondary side of the CT under test, and an appropriate test mode is selected. The device will then excite the CT using simulated current or other methods to determine the CT's wiring direction.

[0003] In the prior art, the invention patent with publication number CN111123171B discloses a telescopic mutual inductance current polarity testing device. It achieves conductive connection by using a handheld telescopic rod to drive the gripper device, and the gripper is set as a ring structure with torsion spring connection, which facilitates the connection and disconnection of the current transformer conductor. However, when clamping the terminal to be tested, if the wiring at the terminal position is complicated or there is an obstruction, the ring structure is easy to fail to clamp, which affects the testing efficiency. Summary of the Invention

[0004] This invention provides a portable CT polarity testing device to solve the problem of poor mobility of the clamping structure in existing testing devices.

[0005] The portable CT polarity testing device of the present invention adopts the following technical solution:

[0006] A portable CT polarity testing device includes a tester, leads, a handheld lever, and a clamping mechanism. There are at least two leads, each with one end connected to an output terminal on the tester. The handheld lever and clamping mechanism each correspond one-to-one with a lead, and the clamping mechanism is mounted on the handheld lever. The clamping mechanism is used to clamp external device terminals and includes a fixing part, a turntable, clamping rods, and a pull cord. The fixing part is fixed to the handheld lever. There are two turntables, coaxial and rotating about an axis perpendicular to the handheld lever, mounted on the fixing part and always rotating in opposite directions. There are four clamping rods spaced circumferentially around the turntables. Two opposing clamping rods are slidably mounted at one end on the same turntable. The turntable drives its two corresponding clamping rods to swing around the rotation axis of the turntable through an elastic element. When one clamping rod abuts against the equipment terminal, it can continue to rotate and drive the other clamping rod to swing. Each clamping rod is electrically connected to the wire on both sides of the turntable in the circumferential direction. One end of each of the two pull ropes is connected to one of the turntables and is located on both sides of the turntable. They are used to pull the turntable to rotate in opposite directions, so that the four clamping rods move closer to each other in pairs. After two of the clamping rods clamp the equipment terminal, the pull ropes are fixed to the hand handle.

[0007] Optionally, the turntable has two arc grooves extending circumferentially thereon, the arc grooves being coaxial with the rotation axis of the turntable; the clamping rods are arranged radially along the turntable, one end of each clamping rod is slidably engaged with an arc groove through a sliding member, and the sliding member and the arc groove are respectively connected at both ends of their circumferential direction by an elastic member; the clamping rods and the fixing part are slidably engaged along an arc-shaped trajectory coaxial with the rotation axis of the turntable, the fixing part restricts the clamping rods from rotating around the sliding member and allows the clamping rods to swing around the rotation axis of the turntable.

[0008] Optionally, the clamping rod has clamping surfaces on both sides of the turntable circumferential direction; the clamping rod is hollow inside, and air blowing holes communicating with the inside of the clamping rod are opened on the clamping surfaces; an air bladder is provided between two adjacent clamping rods, and each air bladder is communicating with the inside of two adjacent or non-adjacent clamping rods, so as to blow air to clean the equipment terminals by squeezing the air bladder when the clamping rods approach each other.

[0009] Optionally, a grid strip is provided at the end of the clamping rod away from the turntable. There are multiple grid strips, all perpendicular to the rotation axis of the turntable, and they are arranged at intervals along the rotation axis of the turntable. The grid strips of two adjacent clamping rods are staggered in the rotation axis direction of the turntable.

[0010] Alternatively, the two turntables are driven by a gear mechanism, which causes the two turntables to rotate in opposite directions.

[0011] Optionally, the handheld lever is provided with multiple buckles, which are spaced apart along the axial direction of the handheld lever. The end of the pull rope is connected to a locking post. After the pull rope drives the turntable to rotate, it engages with the buckles through the locking post, preventing the turntable from resetting and keeping the clamping lever in a clamped state.

[0012] The beneficial effects of the present invention are as follows: The portable CT polarity testing device of the present invention defines four clamping ranges by setting four clamping rods around the turntable. In use, the appropriate clamping range can be selected according to the position of the device terminal to clamp it. The turntable is driven to rotate by the pull rope to drive the clamping rods to swing for clamping. It can adapt to environments with complex circuits and where it is difficult for humans to operate directly, thus increasing the convenience of clamping.

[0013] Furthermore, the four clamping rods are independent of each other. When two of the clamping rods are in contact with the equipment terminals, the turntable can also drive the other two clamping rods to continue swinging until they retract, reducing the space occupied by the clamping rods when they are not in operation, and thus reducing their impact on the testing process.

[0014] Furthermore, an airbag is installed between two adjacent clamping rods. Each airbag is connected to the interior of two adjacent or non-adjacent clamping rods. When the clamping rods approach each other, the airbag is squeezed to blow air to clean the device terminals, ensuring that the contact position is clean and preventing foreign objects from affecting the clamping and conductivity effects.

[0015] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the handheld lever and clamping mechanism of the present invention.

[0018] Figure 3 This is a schematic diagram showing the disassembled clamping mechanism of the present invention.

[0019] Figure 4 for Figure 2 Enlarged diagram of point A in the middle.

[0020] Figure 5 This is a schematic diagram showing the connection between the airbag and the clamping rod of the present invention.

[0021] Figure 6 This is a cross-sectional schematic diagram of the clamping mechanism of the present invention.

[0022] In the diagram: 100, Tester; 200, Wire; 300, Handheld lever; 310, Buckle; 400, Clamping mechanism; 410, Fixing part; 411, Ring groove; 420, Upper turntable; 421, Arc groove; 422, Gear shaft; 430, Lower turntable; 440, Clamping rod; 441, Air hole; 442, Grille bar; 443, Sliding column; 450, Pull rope; 451, Locking column; 461, Central gear; 462, Double gear; 463, Gear ring; 470, Sliding component; 480, Airbag; 481, Hose. Detailed Implementation

[0023] An embodiment of the portable CT polarity testing device of the present invention, such as... Figures 1 to 6 As shown, it includes a tester 100, a wire 200, a handheld lever 300, and a clamping mechanism 400.

[0024] There are at least two wires 200, and one end of each wire 200 is connected to an output terminal on the tester 100.

[0025] Both the handheld lever 300 and the clamping mechanism 400 correspond one-to-one with the wire 200, and the clamping mechanism 400 is mounted on the handheld lever 300.

[0026] The clamping mechanism 400 is used to clamp external device terminals and includes a fixing part 410, a turntable, clamping rods 440, and a pull rope 450; the fixing part 410 is fixed to the hand handle 300. There are two turntables, coaxial and rotatably mounted on the fixing part 410 about an axis perpendicular to the hand handle 300, and they always rotate in opposite directions. There are four clamping rods 440, spaced apart around the turntable. Two opposite clamping rods 440 are slidably mounted on the same turntable at one end. The turntable drives its corresponding two clamping rods 440 to swing around the rotation axis of the turntable through an elastic element, and when one clamping rod 440 abuts against the device terminal, it can continue to rotate and drive the other clamping rod 440 to swing. Each clamping rod 440 is electrically connected to a wire 200 on both sides of the turntable in the circumferential direction; specifically, the wire 200 can be electrically connected to the clamping rod 440 through the fixing part 410, or it can pass through the fixing part 410 and be electrically connected to all four clamping rods 440 simultaneously. One end of each of the two pull ropes 450 is connected to one of the turntables and is located on both sides of the turntable. They are used to pull the turntables to rotate in opposite directions, so that the four clamping rods 440 come closer to each other in pairs. After the pull ropes 450 clamp the equipment terminals of two of the clamping rods 440, they are fixed to the hand handle 300.

[0027] In use, the operator holds the handle 300, and the wire 200 passes through the handle 300 and is electrically connected to the clamping rod 440. Two appropriate clamping rods 440 are selected according to the position of the device terminals. Pulling one of the pull ropes 450 rotates the turntable. The two turntables rotate in opposite directions, causing the two clamping rods 440 on both sides of the device terminals to move closer together. Simultaneously, the other two clamping rods 440 also move closer together until the two clamping rods 440 on both sides of the device terminals abut against the terminals. The turntable continues to rotate, increasing the clamping force between the clamping rods 440 and the device terminals, and causing the other two clamping rods 440 to move closer together further, reducing their impact on the device under test. After clamping, the other end of the pull rope 450 is fixed to the handle 300. When one pull rope 450 is pulled to rotate the turntable, the other pull rope 450 is in a slack state.

[0028] By setting four clamping rods 440 around the turntable to define four clamping zones, during use, the appropriate clamping zone can be selected according to the position of the equipment terminal to clamp it. The turntable is driven to rotate by the pull rope 450, which in turn drives the clamping rods 440 to swing for clamping. This can adapt to environments with complex circuits and where it is difficult for humans to operate directly, thus increasing the convenience of clamping.

[0029] Furthermore, the four clamping rods 440 are independent of each other. When two of the clamping rods 440 are in contact with the equipment terminals, the turntable can also drive the other two clamping rods 440 to continue to swing until they retract, reducing the space occupied by the clamping rods 440 when they are not in operation, thereby reducing their impact on the testing process.

[0030] In this embodiment, the handheld lever 300 is a hollow telescopic lever structure, composed of multiple threaded tubes connected in sequence. The overall length of the handheld lever 300 can be adjusted by rotating the threaded tubes to meet different usage requirements.

[0031] In this embodiment, two arc grooves 421 extending circumferentially are formed on the turntable, and the arc grooves 421 are coaxial with the rotation axis of the turntable; the clamping rods 440 are arranged radially along the turntable, and one end of each clamping rod 440 is slidably engaged with an arc groove 421 through a sliding member 470, and the sliding member 470 and the arc groove 421 are respectively connected at their two ends in the circumferential direction by an elastic member; wherein, the elastic member is a spring, when the turntable rotates, it compresses one side of the elastic member to drive the sliding member 470 to rotate synchronously, thereby driving the clamping rods 440 to swing. After one of the clamping rods 440 abuts against the device terminal, the turntable continues to rotate to further compress the elastic member on one side of the sliding member 470 of the clamping rod 440, and drives the other clamping rod 440 to continue to swing. The sliding member 470 includes a slider slidably disposed within the arc groove 421 and a retaining plate engaged with the clamping rod 440. The retaining plate is connected to the slider via a connecting rod, and the retaining plate is in surface contact with the clamping rod 440, which can restrict the rotation of the clamping rod 440 around the slider to a certain extent. The clamping rod 440 and the fixing part 410 slide in a curved trajectory coaxial with the rotation axis of the turntable. The fixing part 410 restricts the rotation of the clamping rod 440 around the sliding member 470 and allows the clamping rod 440 to swing around the rotation axis of the turntable. Specifically, the fixing part 410 has at least two annular grooves 411, which are coaxial with the rotation axis of the turntable and spaced apart. Each clamping rod 440 is provided with at least two sliding posts 443, and each sliding post 443 is slidably installed in one annular groove 411.

[0032] In this embodiment, the clamping rod 440 has clamping surfaces on both sides of the turntable circumferential direction. The clamping rod 440 is hollow inside, and air blowing holes 441 communicating with the interior of the clamping rod 440 are opened on the clamping surfaces. An air bladder 480 is provided between two adjacent clamping rods 440. Each air bladder 480 is connected to the interior of two adjacent or non-adjacent clamping rods 440 through two hoses 481, so that when the clamping rods 440 approach each other, air is blown into the device terminals by squeezing the air bladders 480 to clean the contact positions and prevent foreign objects from affecting the clamping and conductivity effects. A one-way valve is provided on the air bladder 480 to communicate with the outside. The one-way valve allows gas to enter the air bladder 480 so that the air bladder 480 can inflate and recover when the two clamping rods 440 move away from each other and reset.

[0033] In this embodiment, a grid strip 442 is provided at the end of the clamping rod 440 away from the turntable. There are multiple grid strips 442, all perpendicular to the rotation axis of the turntable, and they are arranged at intervals along the rotation axis. The grid strips 442 of adjacent clamping rods 440 are staggered along the rotation axis of the turntable. Preferably, the grid strip 442 is an arc-shaped strip with its concave surface facing the center of the turntable. When two clamping rods 440 approach each other to clamp the device terminal, the grid strips 442 at the ends of the two clamping rods 440 are staggered, preventing the device terminal from detaching from the end of the two clamping rods 440 away from the turntable.

[0034] In this embodiment, the two turntables are driven by a gear mechanism, which causes the two turntables to rotate in opposite directions. Specifically, the gear mechanism includes a central gear 461, a double gear 462, and a gear ring 463. The central gear 461 is rotatably mounted on the fixed part 410 and is coaxial with the rotation axis of the turntable. The two turntables are an upper turntable 420 and a lower turntable 430. A gear shaft 422 is coaxially fixed on the side of the upper turntable 420 near the lower turntable 430. The gear shaft 422 passes through the fixed part 410 and is connected to the central gear 461 to drive the central gear 461 to rotate synchronously. The gear ring 463 is disposed on the lower turntable 430 and is coaxial with the rotation axis of the lower turntable 430. The double gear 462 is rotatably mounted on the fixed part 410 and includes two coaxial and fixedly connected large gears and small gears. The large gears and small gears mesh with the gear ring 463 and the central gear 461, respectively, so that the gear ring 463 and the central gear 461 rotate at the same speed but in opposite directions.

[0035] In this embodiment, the handheld lever 300 is provided with multiple buckles 310, which are spaced apart along the axial direction of the handheld lever 300. The end of the pull rope 450 is connected to a locking post 451. After the pull rope 450 drives the turntable to rotate, it engages with the buckles 310 through the locking post 451, preventing the turntable from resetting and keeping the clamping lever 440 in a clamped state. The pull rope 450 is connected to both sides of the upper turntable 420 on the same reference diameter, and the reference diameter is perpendicular to the handheld lever 300, so that it is easier to drive the upper turntable 420 to rotate when the pull rope 450 is pulled.

[0036] In this embodiment, the clamping rod 440 gradually increases in size in the circumferential direction of the turntable from the end closer to the turntable to the end farther away from the turntable.

[0037] In use, the portable CT polarity testing device of the present invention allows the operator to first use the hand lever 300 to clamp the device terminal with the clamping lever 440, and then connect the wire 200 to the testing instrument 100. Specifically, the operator holds the hand lever 300, selects two appropriate clamping levers 440 according to the position of the device terminal, pulls one of the pull ropes 450 to rotate the upper turntable 420, and the upper turntable 420 drives the lower turntable 430 to rotate in the opposite direction at the same speed through a gear mechanism. This causes the two clamping levers 440 located on both sides of the device terminal to move closer to each other, and at the same time, the other two clamping levers 440 also move closer to each other until the two clamping levers 440 on both sides of the device terminal abut against the device terminal. Continuing to pull the pull rope 450 causes the upper turntable 420 to rotate, increasing the clamping force between the two clamping levers 440 and the device terminal, and causing the other two clamping levers 440 to move closer together and retract, reducing their impact on the device under test. After clamping, the other end of the pull rope 450, the locking post 451, is engaged with the corresponding buckle 310 on the hand handle 300. After the clamping mechanisms 400 of the two wires 200 clamp the corresponding device terminals, the other end of the wires 200 can be connected to the tester 100, and the polarity of the device terminals can be tested by operating the tester 100.

[0038] 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 principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A portable CT polarity testing device, characterized in that: Includes a tester (100), a wire (200), a handheld lever (300), and a clamping mechanism (400); There are at least two wires (200), one end of each wire (200) is connected to an output terminal on the tester (100); The handheld lever (300) and the clamping mechanism (400) are each corresponding to the wire (200), and the clamping mechanism (400) is mounted on the handheld lever (300); The clamping mechanism (400) is used to clamp external device terminals and includes a fixing part (410), a turntable, clamping rods (440), and a pull rope (450). The fixing part (410) is fixed to the hand handle (300). There are two turntables, which are coaxial and rotate around an axis perpendicular to the hand handle (300) and are mounted on the fixing part (410), and always rotate in opposite directions. There are four clamping rods (440), which are spaced apart around the turntable. One end of two opposing clamping rods (440) is slidably mounted on the same turntable, and the turntable drives its corresponding two clamping rods (440) through an elastic element. The lever (440) swings around the rotation axis of the turntable and continues to rotate to drive the other lever (440) to swing when one of the clamping rods (440) abuts against the device terminal. Each clamping rod (440) is electrically connected to the wire (200) on both sides of the turntable in the circumferential direction. One end of each of the two pull ropes (450) is connected to one of the turntables and located on both sides of the turntable. They are used to pull the turntable to rotate in opposite directions so that the four clamping rods (440) move closer to each other in pairs. After two of the clamping rods (440) clamp the device terminal, the pull ropes (450) are fixed to the hand lever (300).

2. The portable CT polarity testing device according to claim 1, characterized in that: Two arc grooves (421) extending circumferentially are provided on the turntable, and the arc grooves (421) are coaxial with the rotation axis of the turntable; clamping rods (440) are arranged radially along the turntable, and one end of each clamping rod (440) is slidably engaged with an arc groove (421) through a sliding member (470), and the sliding member (470) and the arc groove (421) are respectively connected by an elastic member at both ends of their circumferential direction; the clamping rods (440) and the fixing part (410) are slidably engaged along an arc trajectory coaxial with the rotation axis of the turntable, and the fixing part (410) restricts the clamping rods (440) from rotating around the sliding member (470) and allows the clamping rods (440) to swing around the rotation axis of the turntable.

3. The portable CT polarity testing device according to claim 1, characterized in that: The clamping rod (440) has clamping surfaces on both sides of the turntable circumferential direction; the clamping rod (440) is hollow inside, and the clamping surface is provided with an air blowing hole (441) that communicates with the inside of the clamping rod (440); an air bag (480) is provided between two adjacent clamping rods (440), and each air bag (480) is connected to the inside of two adjacent or non-adjacent clamping rods (440) so that when the clamping rods (440) approach each other, the air bag (480) is squeezed to blow air to clean the equipment terminals.

4. The portable CT polarity testing device according to claim 1, characterized in that: A grid strip (442) is provided at the end of the clamping rod (440) away from the turntable. There are multiple grid strips (442), all of which are perpendicular to the rotation axis of the turntable and are arranged at intervals along the rotation axis of the turntable. The grid strips (442) of two adjacent clamping rods (440) are staggered in the rotation axis direction of the turntable.

5. A portable CT polarity testing device according to claim 1, characterized in that: The two turntables are driven by a gear mechanism, which causes the two turntables to rotate in opposite directions.

6. The portable CT polarity testing device according to claim 1, characterized in that: The handheld lever (300) is provided with multiple buckles (310), which are spaced apart along the axial direction of the handheld lever (300). The end of the pull rope (450) is connected to a locking post (451). After the pull rope (450) drives the turntable to rotate, it engages with the buckle (310) through the locking post (451), preventing the turntable from resetting and keeping the clamping lever (440) in a clamped state.

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