Current transformer with high wire clamping strength

Abstract

The invention discloses a current transformer with high wire clamping strength, which comprises a body and a primary side threading hole through which a cable penetrates, two ends of the body extend outwards to be provided with a shell, a core tube is sleeved in the primary side threading hole, two ends of the core tube are respectively provided with a head end clamp and a tail end clamp, the head end clamp comprises a limiting disc, a sliding rod, a guide disc and a tripping unit, and the limiting disc is arranged on the sliding rod. The tail end clamp comprises an execution cylinder, a guide ring and a pushing unit, the pushing unit comprises a helical tooth plate and an arc-shaped plate, a guide hole is formed in the side wall of the guide body, the helical tooth plate is installed in the guide hole, the arc-shaped plate is fixedly arranged at the end of the helical tooth plate, and the guide ring is arranged in the arc-shaped plate. When the execution cylinder is screwed, the core tube drives the sliding rod to move to achieve clamping, the tripping unit relieves force application, and the pushing unit clamps the cable and pushes the cable to be straightened. The cable clamping device is suitable for cables of different thicknesses, clamping is stable, potential safety hazards are reduced, the measurement precision is improved, the cables are clamped and fixed in the middle, bending is avoided, and the measurement precision is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of mutual inductors, and in particular to a current mutual inductor with high clamping strength. Background Art

[0002] Current transformer is an important measuring device used in power system, mainly used to measure and monitor the current in the line. Its basic working principle is to convert the large current on the primary side into the small current on the secondary side in proportion through the electromagnetic induction between the primary winding and the secondary winding, so as to facilitate the measurement by the measuring instrument.

[0003] A Chinese patent document (publication number: CN221529660U) discloses a power transformer with high wire clamping strength. In this utility model, the user first pulls the push-pull rod to pull up the upper clamping plate, and then passes the cable through the threading port of the lower clamping plate. Then the user connects the cable passing through the other end to the power transformer. At this time, the user releases the push-pull rod, and the upper clamping plate falls to clamp the cable, so that the cable can be quickly fixed, which improves the work efficiency of the staff. Then the user rotates the threaded rod, and the threaded rod drives the clamping block to move downward, so that the cable near the power transformer can be firmly fixed, which improves the clamping effect of the cable, prevents the cable from loosening, and improves the use effect of the device.

[0004] In the prior art, the working principle of the current transformer is to convert the large current on the primary side into the small current on the secondary side in proportion through the electromagnetic induction between the primary winding and the secondary winding. When the cable position is unstable or not centered, the relative position relationship between the primary conductor and the secondary winding will change. This position change directly affects the electromagnetic induction intensity and coupling effect, resulting in unstable conversion ratio and deviation in measured value. Unstable cable clamping may cause the cable to collide with the inner wall of the transformer, and long-term shaking may cause wear on the cable sheath. In a high current working environment, unstable contact may produce hot spots, posing a safety hazard. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a current transformer with high clamping strength, which can adapt to cables of different thicknesses, has stable clamping, reduces safety hazards, and improves measurement accuracy; it clamps and fixes the cable in the center to avoid bending and ensure measurement accuracy.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A current transformer with high clamping strength comprises a body and a primary side threading hole for threading cables; both ends of the primary side threading hole of the body are extended outward to set a shell, a core tube is sleeved in the primary side threading hole of the body, and a head end clamp and a tail end clamp are respectively arranged at both ends of the core tube; the head end clamp comprises a limit plate, a slide rod, a guide plate and a release unit, a center line hole is arranged on the limit plate and the guide plate, one end of the core tube is rotatably connected to the guide plate through the release unit, the guide plate is installed in the shell, and a plurality of guide grooves are arranged in an array on the guide plate; the limit plate is fixedly installed on the outer side of the guide plate, and a plurality of slide grooves are arranged in a circumferential array on the guide plate to communicate with the wire hole, slide rods are installed in the slide grooves, and guide rods are fixed at the ends of the slide rods away from the wire hole, and the guide rods are all slid through It is arranged in the corresponding guide groove; when the core tube drives the guide disk to rotate, several guide grooves drive the sliding rods to move toward the center line hole of the limit disk; the tail end clamp includes an execution cylinder, a guide ring and a pushing unit, one end of the execution cylinder is fixedly connected to the core tube, and the other end of the execution cylinder is an open structure. A guide body is arranged inside the execution cylinder, and the guide body is fixedly connected to the bottom of the main body through a support frame. A pushing unit is radially arranged on the guide body, and the execution cylinder is transmitted to the pushing unit through the guide ring; when the execution cylinder is screwed, several sliding rods in the head end clamp are driven by the core tube to move toward the cable to achieve clamping. After the cable is clamped, the force on the head end clamp is released under the action of the tripping unit, and the pushing unit in the tail end clamp clamps the cable and pushes it outward to straighten it.

[0007] As a preferred technical solution of the present invention, the pushing unit includes a beveled tooth plate and an arc plate, a plurality of guide holes are provided on the side wall of the guide body, a beveled tooth plate is installed in the guide holes, an arc plate is fixed at the end of the beveled tooth plate, and the arc plate is located on the side away from the actuator cylinder; a guide ring is installed on the outer periphery of the guide body, the guide ring is located on the bottom ring of the guide body, the internal thread of the guide ring is matched with the beveled tooth plate for transmission; the outer periphery of the guide ring is connected to the inner wall of the actuator cylinder by a spline.

[0008] As a preferred technical solution of the present invention, the guide holes penetrate the side wall and the bottom ring of the guide body to form corresponding guide channels.

[0009] As a preferred technical solution of the present invention, a spline is arranged on the inner periphery of the actuator cylinder, and a spline groove is arranged on the outer periphery of the guide ring. Through the cooperation between the spline and the spline groove, the power of the actuator cylinder is transmitted to the guide ring.

[0010] As a preferred technical solution of the present invention, the release unit includes a cover body, one end of the cover body is sleeved on the outer periphery of the core tube, and the other end of the cover body is fixedly connected to the guide disk, and a limit ring, a disc spring, a ball, a retaining ring and a linkage ring are arranged inside the cover body; the retaining ring is fixedly installed on the guide disk, and the center line hole of the limit disk is located in the retaining ring, the end of the core tube is fixedly connected to the linkage ring, and the linkage ring abuts the inner top wall of the cover body; a plurality of ball reset grooves are arranged in an outer peripheral array of the retaining ring, and balls are installed in the ball reset grooves, and ball positioning grooves are provided on the linkage rings adjacent to the balls, a limit ring is installed on the side of the ball away from the linkage ring, and a disc spring is installed on the side of the limit ring away from the ball; under normal conditions, the limit ring squeezes the ball into the ball positioning groove to transmit and connect the core tube and the guide disk, and when the torque is overloaded, the ball disengages from the ball positioning groove and enters the other end of the ball reset groove to release the transmission.

[0011] As a preferred technical solution of the present invention, a limit assembly is arranged between the slide rod and the slide groove, and the limit assembly includes a reset spring, a ratchet rod and a reset rod. An inclined groove is opened on one side of the slide groove, and a reset spring and a ratchet rod are installed in the inclined groove, and a reset lever is arranged on the ratchet rod; a ratchet is arranged on the side wall of the slide rod adjacent to the ratchet rod, and a reverse ratchet is arranged on the end of the ratchet rod to match the ratchet.

[0012] As a preferred technical solution of the present invention, the guide plate is installed in the housing at one end through a first bearing; and the end of the actuator cylinder close to the core tube is installed in the housing at the other end through a second bearing.

[0013] As a preferred technical solution of the present invention, a protrusion is arranged on the outer periphery of the limiting disk, and a groove is provided on the inner wall of the shell close to the limiting disk, and the protrusion is matched with the groove.

[0014] As a preferred technical solution of the present invention, the inner side of the arc-shaped plate is provided with anti-slip grooves, and the anti-slip grooves are distributed in a radial array to increase the contact friction with the cable.

[0015] As a preferred technical solution of the present invention, a plurality of evenly distributed ventilation holes are provided on the outer peripheral surface of the cover.

[0016] As a preferred technical solution of the present invention, a method for clamping a line using a current transformer comprises the following steps: S1. Insert the cable through the primary side threading hole of the main body and pass it through the head end clamp and the tail end clamp; S2. Screw the actuator cylinder with anti-slip patterns to drive the head end fixture and the tail end fixture to move synchronously through the core tube. At this time, the protrusion of the limit plate is embedded in the groove of the shell to prevent the limit plate from rotating with the guide plate. S3. The guide plate in the head end fixture drives the guide rod and the slide rod to slide in the slide groove through the arc guide groove. Several slide rods move toward the center to clamp the cables first. The ratchet on the side wall of the slide rod cooperates with the reverse ratchet on the end of the ratchet rod to prevent the slide rod from moving in the opposite direction. S4. When the head-end clamp reaches the predetermined clamping force, the ball in the release unit is disengaged from the ball positioning groove of the linkage ring under the action of the disc spring, interrupting the power transmission of the core tube to the guide plate. At the same time, the ratchet rod in the limit assembly engages with the ratchet teeth of the sliding rod to lock the clamping position of the cable; S5. The tail end clamp continues to operate, and the helical tooth plate cooperates with the internal thread of the guide ring to transmit the cable, so that the arc plate with radial array anti-slip grooves clamps the other end of the cable, and generates an outward thrust during the clamping process to keep the cable straight, ensuring that the cable is in the center position in the current transformer.

[0017] 1. The present invention adopts a structure in which a core tube runs through the body, and a head end clamp and a tail end clamp are arranged at both ends of the core tube. The synchronous clamping of the head and tail ends is realized by rotating the execution cylinder. With the graded clamping function of the tripping unit, it can adapt to cables of different thicknesses, and the clamping is stable and reliable, reducing safety hazards. At the same time, through the tensioning effect of the pushing unit, the cable is arranged in the center, the relative position between the primary side cable and the secondary winding is guaranteed, the electromagnetic induction intensity and the coupling effect and the conversion ratio are stabilized, and the measurement accuracy is improved; the unstable clamping causes the cable to avoid long-term collision with the inner wall of the mutual inductor, avoids the cable outer skin from being worn and generating hot spots, and ensures safety; In terms of operational convenience, the present invention realizes double-end clamping with a single rotation, automatic release to avoid over-clamping, and automatic locking of the ratchet structure, which not only ensures the clamping effect, but also improves the operational convenience and ensures the measurement accuracy.

[0018] 2. In the present invention, the head end clamp adopts the matching structure of the guide plate and the slide bar. Through the arc-shaped guiding effect of the guide groove, multiple slide bars are synchronously moved centripetally to form a uniform clamping force, avoid cable eccentricity, and improve the accuracy of measurement; the limit assembly realizes the position locking of the slide bar through the cooperation of the ratchet and the reverse ratchet to ensure the continuity and stability of the clamping force. The guide plate is installed in the housing through the first bearing to reduce movement friction, improve stability and transmission efficiency; the convex block of the limit plate is matched with the groove on the inner wall of the housing to form a reliable limit guide to prevent shaking during the clamping process.

[0019] 3. In the present invention, the pushing unit in the tail end clamp adopts a combined structure of a bevel tooth plate and an arc plate. Through the transmission cooperation between the internal thread of the guide ring and the bevel tooth plate, an outward thrust is generated while clamping the cable, so that the cable remains in a straight state and has a position locking function, avoiding cable shaking and bending, and further ensuring measurement accuracy; the guide hole passes through the side wall and the bottom ring of the guide body to form a complete guide channel to ensure the smooth movement of the bevel tooth plate; the execution cylinder is installed in the shell through the second bearing to achieve flexible rotation while maintaining movement stability.

[0020] 4. In the present invention, the tripping unit adopts a combined structure of a ball and a disc spring. By setting a suitable tripping torque threshold, the transmission is automatically released after the head end clamp reaches a predetermined clamping force, thereby preventing excessive clamping from damaging the cable. At the same time, the tail end clamp is ensured to continue to operate to complete the tensioning and fixing of the cable, thereby realizing intelligent control of graded clamping and improving the safety and reliability of the device. The outer peripheral surface of the cover is provided with evenly distributed ventilation holes to provide a good heat dissipation channel and extend the service life of the device. The coordinated design of the linkage ring and the retaining ring ensures reliable resetting after tripping, which is convenient for the next use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the overall installation structure of the head end fixture of the current transformer of the present invention; Figure 2 It is a three-dimensional schematic diagram of the overall installation structure of the tail end fixture of the current transformer of the present invention; Figure 3 It is a three-dimensional schematic diagram of the split structure of the current transformer of the present invention; Figure 4 It is a three-dimensional schematic diagram of the split structure of the tail end fixture of the current transformer of the present invention; Figure 5 It is a three-dimensional schematic diagram of the split structure of the head end fixture and the tail end fixture of the current transformer of the present invention; Figure 6 It is a three-dimensional schematic diagram of a partial cross-sectional structure of a trip unit of a current transformer of the present invention; Figure 7 It is a three-dimensional schematic diagram of the installation structure of the limit assembly of the current transformer of the present invention; In the figure: body 11; actuator cylinder 12; limit plate 13; protrusion 14; slide groove 15; slide rod 16; support frame 17; arc plate 18; guide ring 19; guide body skirt 20; first bearing 21; second bearing 22; core tube 23; housing 24; groove 25; guide body 26; bottom ring 27; guide hole 28; helical tooth plate 29; spline Groove-30; spline-31; guide plate-32; guide groove-33; guide rod-34; internal thread-35; release unit-36; cover body-37; limit ring-38; disc spring-39; retaining ring-40; ball-41; linkage ring-42; ratchet-43; inclined groove-44; reset spring-45; reset rod-46; ratchet rod-47; reverse ratchet-48; limit assembly-49. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] Contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0024] Figure 1-Figure 7As shown in, a current transformer with high clamping strength includes a body 11 and a primary side threading hole for threading cables; both ends of the primary side threading hole of the body 11 are extended outward to set a shell 24, a core tube 23 is sleeved in the primary side threading hole of the body 11, and the two ends of the core tube 23 are respectively provided with a head end clamp and a tail end clamp; the head end clamp includes a limit plate 13, a slide bar 16, a guide plate 32 and a release unit 36, a center line hole is provided on the limit plate 13 and the guide plate 32, one end of the core tube 23 is rotatably connected to the guide plate 32 through the release unit 36, the guide plate 32 is installed in the shell 24, and a plurality of guide grooves 33 are arranged in an array on the guide plate 32; the limit plate 13 is fixedly installed on the outer side of the guide plate 32, and a plurality of slide grooves 15 are arranged along the circumference of the guide plate 32 to communicate with the wire hole, and slide bars 16 are installed in the slide grooves 15, and a guide rod 34 is fixed at the end of the slide bar 16 away from the wire hole, and the guide groove 15 is connected to the wire hole. The rods 34 are all slidably inserted into the corresponding guide grooves 33; when the core tube 23 drives the guide plate 32 to rotate, several guide grooves 33 drive the slide rods 16 to move toward the center line hole of the limit plate 13; the tail end clamp includes an execution cylinder 12, a guide ring 19 and a pushing unit, one end of the execution cylinder 12 is fixedly connected to the core tube 23, and the other end of the execution cylinder 12 is an open structure. A guide body 26 is arranged inside the execution cylinder 12, and the guide body 26 is fixedly connected to the bottom of the main body 11 through a support frame 17. A pushing unit is radially arranged on the guide body 26, and the execution cylinder 12 is transmitted to the pushing unit through the guide ring 19; when the execution cylinder 12 is screwed, several slide rods 16 in the head end clamp are driven by the core tube 23 to move toward the cable to achieve clamping. After the cable is clamped, the force on the head end clamp is released under the action of the release unit 36, and the pushing unit in the tail end clamp clamps the cable and pushes it outward to straighten it.

[0025] In the through-type current transformer of the present invention, the cable enters through the primary side threading hole, and the secondary side of the current transformer is connected to an ammeter for measurement; the present invention clamps the cable in the primary side threading hole to keep the cable in a central position and tensioned, thereby ensuring measurement accuracy and avoiding safety hazards caused by cable shaking.

[0026] In the present invention, after the cable is inserted into the primary side threading hole of the current transformer, the execution cylinder 12 is screwed to drive the head end clamp and the tail end clamp to clamp the cable. Since the head end clamp is driven by the arc guide groove 33 in the guide plate 32, and the tail end clamp is driven by the helical tooth plate 29 and the internal thread 35 of the guide ring 19, the displacement of the head end clamp is greater than that of the tail end clamp, so the head end clamp will preferentially clamp the cable.

[0027] The transmission is realized by the fixed connection between the head end clamp and the tail end clamp through the core tube 23, and a release unit 36 ​​is arranged between the head end clamp and the core tube 23. When the torque borne by the head end clamp after clamping the cable is greater than the threshold set by the release unit 36, the linkage component in the release unit 36 ​​is disconnected, interrupting the power transmission of the core tube 23 to the guide plate 32. At this time, the limit assembly 49 in the head end clamp locks the clamping position of the cable; the tail end clamp continues to run to clamp the cable. During the clamping process, the arc plate 18 of the tail end clamp pushes the cable outward to tension the cable, thereby avoiding safety hazards caused by cable shaking, further ensuring that the cable is in the center position in the current transformer, and improving the measurement accuracy.

[0028] The outer periphery of the execution cylinder 12 is provided with anti-skid patterns to facilitate the application of force during twisting.

[0029] During use, after the cable is inserted from the primary side threading hole of the current transformer, the execution cylinder 12 is screwed, and the execution cylinder 12 drives the core tube 23 to rotate. The core tube 23 drives the guide plate 32 of the head end clamp to rotate through the tripping unit 36. The arc guide groove 33 makes the guide rod 34 and the slide bar 16 slide together in the slide groove 15 during the rotation of the guide plate 32. Several slide bars 16 move toward the center to clamp the cable; when the torque borne by the slide bar 16 of the head end clamp after clamping the cable is greater than the threshold set by the tripping unit 36, the linkage component in the tripping unit 36 ​​is disconnected, interrupting the power transmission of the core tube 23 to the guide plate 32. At this time, the limit assembly 49 in the head end clamp locks the clamping position of the cable, and the tail end clamp continues to operate to clamp the other end of the cable; Furthermore, the pushing unit includes a beveled tooth plate 29 and an arc plate 18, the side wall of the guide body 26 is provided with several guide holes 28, the beveled tooth plate 29 is installed in the guide hole 28, the ends of the beveled tooth plate 29 are fixed with arc plates 18, and the arc plate 18 is located on the side away from the actuator cylinder 12; the outer periphery of the guide body 26 is installed with a guide ring 19, the guide ring 19 is located on the bottom ring 27 of the guide body 26, and the internal thread 35 of the guide ring 19 is in transmission cooperation with the beveled tooth plate 29; the outer periphery of the guide ring 19 is connected to the inner wall of the actuator cylinder 12 by a spline; further, the guide hole 28 passes through the side wall of the guide body 26 and the bottom ring 27 to form corresponding guide channels.

[0030] Figure 4 and Figure 5 As shown in the figure, a spline 31 is provided on the inner periphery of the actuator cylinder 12, and a spline groove 30 is provided on the outer periphery of the guide ring 19. Through the cooperation between the spline 31 and the spline groove 30, the power of the actuator cylinder 12 is transmitted to the guide ring 19; It should be noted that during the operation of the execution cylinder 12 , force is applied to the head end clamp and the tail end clamp. Under the action of the release unit 36 ​​, the drive to the head end clamp is released while the execution cylinder 12 continues to apply external force to the guide ring 19 .

[0031] The guide body 26 is cylindrical and has a conical structure, and a bottom ring 27 is fixed on the large end surface of the conical structure; The small end face of the conical structure is the guide body skirt 20, which is located at the end away from the execution cylinder 12. A support frame 17 is fixed on the guide body skirt 20, and the support frame 17 is fixedly connected to the bottom of the body 11; the support frame 17 uniformly supports and fixes the guide body 26, and an annular fixing body can also be set on the guide body skirt 20 to strengthen the supporting effect; The several guide holes 28 penetrate the side wall of the guide body 26 and the bottom ring 27 at an inclined angle, and are all oriented toward the center direction of the guide body skirt 20. When the several beveled tooth plates 29 are driven by the internal thread 35 of the guide ring 19, the several beveled tooth plates 29 make the arc plates 18 approach the center and move outward at the same time, generating a clamping force and forming an outward thrust, which is beneficial to the tensioning, fixing and central arrangement of the cable.

[0032] It should be noted that the internal thread 35 of the guide ring 19 cooperates with the bevel gear plate 29 to generate displacement, and the internal thread 35 has a position locking function for the bevel gear plate 29 .

[0033] Furthermore, the release unit 36 ​​includes a cover body 37, one end of the cover body 37 is sleeved on the outer periphery of the core tube 23, and the other end of the cover body 37 is fixedly connected to the guide plate 32. A limit ring 38, a disc spring 39, a ball 41, a retaining ring 40 and a linkage ring 42 are arranged inside the cover body 37; the retaining ring 40 is fixedly installed on the guide plate 32, and the center line hole of the limit plate 13 is located in the retaining ring 40, the end of the core tube 23 is fixedly connected to the linkage ring 42, and the linkage ring 42 abuts against the inner top wall of the cover body 37; the retaining ring A plurality of ball reset grooves are arranged in an array on the outer periphery of the ring 40, in which balls 41 are installed, and ball positioning grooves are arranged on the linkage ring 42 adjacent to the balls 41, and a limit ring 38 is installed on the side of the balls 41 away from the linkage ring 42, and a disc spring 39 is installed on the side of the limit ring 38 away from the balls 41; under normal conditions, the limit ring 38 squeezes the balls 41 into the ball positioning grooves to transmit and connect the core tube 23 and the guide plate 32, and when the torque is overloaded, the balls 41 disengage from the ball positioning grooves and enter the other end of the ball reset grooves to release the transmission.

[0034] Figure 6As shown in the figure, the upper opening of the cover body 37 limits the linkage ring 42 at the end of the core tube 23, and the linkage ring 42 and the retaining ring 40 are in abutment state; during the transmission process, the disc spring 39 applies force to the limiting ring 38 to squeeze the ball 41, so that the ball 41 enters the ball positioning groove. At this time, the ball 41 is simultaneously located in the linkage ring 42 and the retaining ring 40 and is in a squeezed state to connect the two as a whole for transmission, and finally the core tube 23 and the guide plate 32 are connected for transmission, and the release unit 36 ​​realizes the transmission of the core tube 23 and the head end clamp; When the torsion reaches the threshold of the disc spring 39, the ball 41 will be squeezed out of the ball positioning groove, the linkage ring 42 and the core tube 23 will rotate together, the retaining ring 40 and the guide plate 32 will remain stationary, and the release unit 36 ​​will release the transmission between the core tube 23 and the head end clamp.

[0035] It should be noted that the number of disc springs 39 and the material of the disc springs used can be changed according to the magnitude of the torsion force.

[0036] Furthermore, a limit assembly 49 is arranged between the slide rod 16 and the slide groove 15, and the limit assembly 49 includes a reset spring 45, a ratchet rod 47 and a reset rod 46. An inclined groove 44 is opened on one side of the slide groove 15, and a reset spring 45 and a ratchet rod 47 are installed in the inclined groove 44, and a reset lever 46 is arranged on the ratchet rod 47; a ratchet 43 is arranged on the side wall of the slide rod 16 adjacent to the ratchet rod 47, and a reverse ratchet 48 is arranged at the end of the ratchet rod 47 to match the ratchet 43.

[0037] Figure 7 As shown in the figure, when the slide bar 16 is driven to move toward the center, the ratchet rod 47 will be squeezed into the inclined groove 44; the reverse ratchet 48 cooperates with the ratchet 43 to lock, preventing the slide bar 16 from moving away from the center, thereby locking the position of the slide bar 16 and finally achieving the clamping and fixing of the cable.

[0038] Furthermore, the guide plate 32 is installed in the housing 24 at one end through the first bearing 21 ; and the end of the actuator cylinder 12 close to the core tube 23 is installed in the housing 24 at the other end through the second bearing 22 .

[0039] Figure 3As shown in , the guide plate 32 is installed at one end of the housing 24 through the first bearing 21, and the actuator cylinder 12 is installed at the other end of the housing 24 through the second bearing 22, forming a double-bearing support structure. The first bearing 21 provides rotational support for the guide plate 32 to ensure the stability of the guide plate 32 when rotating around its axis; the second bearing 22 provides rotational support for the actuator cylinder 12 to ensure the stability of the actuator cylinder 12 when driving the core tube 23 to move. The setting of the two bearings enables the guide plate 32 and the actuator cylinder 12 to rotate with the housing 24 as a reference, realizing independent rotational movement relative to the housing 24. The first bearing 21 and the second bearing 22 are respectively located at both ends of the housing 24, forming front and rear support points, which effectively prevent the moving parts from swinging during operation and ensure that the moving parts always run on the designed track.

[0040] Furthermore, a protrusion 14 is provided on the outer periphery of the limiting plate 13 , and a groove 25 is provided on the inner wall of the shell 24 adjacent to the limiting plate 13 , and the protrusion 14 is matched with the groove 25 .

[0041] Figure 3 As shown in , a protrusion 14 is provided on the periphery of the limit plate 13, and a groove 25 is provided on the inner wall of the housing 24 adjacent to the limit plate 13. Through the precise matching of the protrusion 14 and the groove 25, a reliable limit orientation mechanism is formed. When the head end clamp is working, the protrusion 14 is embedded in the groove 25 to prevent the limit plate 13 from rotating with the guide plate 32, ensuring that the radial motion trajectory of the slide bar 16 does not deflect. This convex-concave matching structure can not only withstand a large torque, but also accurately locate the installation angle of the limit plate 13, ensuring that the movement direction of multiple slide bars 16 is always consistent with the preset trajectory.

[0042] The design uses a combination of multiple evenly distributed protrusions 14 and grooves 25, which provides a larger contact area and stronger torsion resistance, and also facilitates quick alignment during assembly. The shape of the protrusion 14 and the inner wall of the groove 25 adopt an interference fit, which not only ensures positioning accuracy, but also avoids looseness during use.

[0043] Furthermore, the inner side of the arc-shaped plate 18 is provided with anti-skid grooves (not shown in the figure), and the anti-skid grooves are distributed in a radial array to increase the contact friction with the cable.

[0044] The inner side of the arc plate 18 is provided with anti-skid patterns, which are evenly distributed in a radial array along the inner surface of the arc plate 18 to form a regular friction enhancement structure. When the tail clamp is working, the anti-skid patterns are in full contact with the cable surface, and the contact area is increased through the microscopic concave-convex structure, which significantly improves the friction coefficient. The radial array distribution of the anti-skid patterns ensures the uniformity of the clamping force on the entire contact surface, avoids local stress concentration, and effectively prevents the cable from sliding or rotating relative to the cable during the measurement process.

[0045] This design not only enhances the reliability of clamping, but also adapts to the surface characteristics of cables of different specifications. The depth and spacing of the anti-slip grooves are optimized to provide sufficient friction while avoiding damage to the cable surface, ensuring the clamping effect while taking into account the service life of the cable.

[0046] Furthermore, the outer peripheral surface of the cover body 37 is provided with a plurality of evenly distributed ventilation holes.

[0047] Figure 6 As shown in , the outer peripheral surface of the cover body 37 is provided with a plurality of evenly distributed ventilation holes (not shown in the figure), forming a complete natural convection heat dissipation system.

[0048] The concentration of thermal stress caused by excessive local temperature is avoided, and the influence of temperature change on the elasticity of disc spring 39 is also reduced, ensuring the sensitivity and reliability of trip unit 36. This ventilation structure not only improves the adaptability of the device in high temperature environment, but also prolongs the service life of internal parts, especially disc spring 39. By effectively controlling the working temperature, the influence of thermal deformation on the measurement accuracy is reduced, and the working stability of the device under various environmental conditions is improved. In addition, the setting of the ventilation holes also facilitates the natural discharge of dust accumulated inside, reduces the maintenance frequency, and improves the practicality and reliability of the device.

[0049] In the present invention, the components arranged outside the body 11: the shell 24, the core tube 23, the limit plate 13, the slide rod 16, the guide plate 32, the release unit 36, the execution cylinder 12, the guide ring 19, the guide body 26, the support frame 17, the guide rod 34, the bevel gear plate 29, the arc plate 18, the guide ring 19, the bottom ring 27, the first bearing 21, the second bearing 22, the limit ring 38, the disc spring 39, the ball 41, the retaining ring 40, the linkage ring 42, the cover body 37, the reset spring 45, the ratchet rod 47, the reset rod 46, the bump 14, etc. are all made of non-magnetic materials.

[0050] The use of non-magnetic materials can effectively avoid the influence of external components on the measurement accuracy of the current transformer, prevent magnetic field interference, and ensure the accuracy of the measured data. These components are made of non-magnetic materials such as copper alloy, aluminum alloy, stainless steel, engineering plastics, etc., which not only ensures mechanical strength, but also does not interfere with the operation of the transformer. Especially when measuring high currents, this material selection can significantly reduce eddy current losses and improve measurement accuracy. At the same time, it also avoids the influence of electromagnetic forces on the components themselves, ensuring the stable operation of the mechanism.

[0051] The method for clamping a line using a current transformer comprises the following steps: S1. Insert the cable from the primary side threading hole of the body 11, pass through the head end fixture and the tail end fixture, and connect the secondary side of the current transformer to the ammeter for measurement; the key components such as the shell 24, core tube 23, and limit plate 13 outside the body 11 are made of non-magnetic materials such as copper alloy, aluminum alloy, and stainless steel to avoid interference with the measurement accuracy; S2. The actuator cylinder 12 with anti-slip patterns is screwed to drive the head end clamp and the tail end clamp to move synchronously through the core tube 23. At this time, the multiple evenly distributed protrusions 14 of the limit plate 13 and the grooves 25 of the shell 24 are interference fit to provide a larger contact area and torsion resistance, thereby preventing the limit plate 13 from rotating with the guide plate 32. The spline 31 provided on the inner circumference of the actuator cylinder 12 cooperates with the spline groove 30 on the outer circumference of the guide ring 19 to realize power transmission. S3, the guide plate 32 in the head end clamp drives the guide rod 34 and the slide rod 16 to slide in the slide groove 15 through the arc guide groove 33, and several slide rods 16 move toward the center to clamp the cable first, and the ratchet 43 on the side wall of the slide rod 16 cooperates with the reverse ratchet 48 at the end of the ratchet rod 47 to prevent the slide rod 16 from moving in the opposite direction; the guide plate 32 is installed in the housing 24 through the first bearing 21 to reduce movement friction and improve transmission efficiency; S4. When the head end clamp reaches the predetermined clamping force, the ball 41 in the release unit 36 ​​is disengaged from the ball positioning groove of the linkage ring 42 under the action of the disc spring 39, interrupting the power transmission of the core tube 23 to the guide plate 32. At the same time, the ratchet rod 47 in the limit assembly 49 engages with the ratchet 43 of the slide bar 16 to lock the clamping position of the cable; the ventilation holes evenly arranged on the periphery of the cover body 37 provide heat dissipation channels, extend the service life of the disc spring 39 and other parts, and reduce the influence of thermal deformation on the measurement accuracy; S5. The tail end clamp continues to operate, and the transmission is coordinated between the bevel plate 29 and the internal thread 35 of the guide ring 19, so that the arc plate 18 with radial array anti-slip grooves clamps the other end of the cable, and generates an outward thrust during the clamping process to keep the cable in a straight state, ensuring that the cable is in a central position in the current transformer; the guide hole 28 of the guide body 26 penetrates the side wall and the bottom ring 27 to form a guide channel, ensuring that the bevel plate 29 moves smoothly, and the execution cylinder 12 is installed in the housing 24 through the second bearing 22, so as to achieve flexible rotation while maintaining movement stability.

[0052] The present invention illustrates the technical concept of the present invention through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that the relevant improvements to the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A current transformer with high clamping strength, comprising a body (11) and a primary side threading hole for threading a cable; both ends of the primary side threading hole of the body (11) are provided with a housing (24) extending outward, characterized in that: A core tube (23) is sleeved in the primary side threading hole of the body (11), and a head end clamp and a tail end clamp are respectively provided at both ends of the core tube (23); The head end fixture comprises a limit plate (13), a slide bar (16), a guide plate (32) and a release unit (36); a center line hole is provided on the limit plate (13) and the guide plate (32); one end of the core tube (23) is rotatably connected to the guide plate (32) via the release unit (36); the guide plate (32) is installed in the housing (24); a plurality of guide grooves (33) are provided in an array on the guide plate (32); the limit plate (13) is fixedly installed on the guide plate On the outer side of the plate (32), a plurality of slide grooves (15) are arranged in a circumferential array on the guide plate (32) and are connected to the wire holes. Slide rods (16) are installed in the slide grooves (15). A guide rod (34) is fixed on the end of the slide rod (16) away from the wire hole. The guide rods (34) are slidably penetrated in the corresponding guide grooves (33). When the core tube (23) drives the guide plate (32) to rotate, the plurality of guide grooves (33) drive the slide rods (16) to move toward the center line hole of the limit plate (13). The tail end clamp comprises an execution cylinder (12), a guide ring (19) and a pushing unit, one end of the execution cylinder (12) is fixedly connected to the core tube (23), the other end of the execution cylinder (12) is an open structure, a guide body (26) is arranged inside the execution cylinder (12), the guide body (26) is fixedly connected to the bottom of the body (11) through a support frame (17), a pushing unit is arranged radially on the guide body (26), and the execution cylinder (12) is transmitted to the pushing unit through the guide ring (19); When the execution cylinder (12) is screwed, the core tube (23) drives the plurality of slide bars (16) in the head end clamp to move toward the cable to achieve clamping. After the cable is clamped, the force applied to the head end clamp is released under the action of the release unit (36), and the pushing unit in the tail end clamp clamps the cable and pushes it outward to straighten it.

2. The current transformer with high clamping strength according to claim 1, characterized in that: The pushing unit comprises a beveled tooth plate (29) and an arc plate (18); a plurality of guide holes (28) are provided on the side wall of the guide body (26); the beveled tooth plate (29) is installed in the guide hole (28); the ends of the beveled tooth plate (29) are fixed with an arc plate (18); the arc plate (18) is located on a side away from the actuator cylinder (12); a guide ring (19) is installed on the outer periphery of the guide body (26); the guide ring (19) is located on the bottom ring (27) of the guide body (26); the internal thread (35) of the guide ring (19) is in transmission cooperation with the beveled tooth plate (29); the outer periphery of the guide ring (19) is connected to the inner wall of the actuator cylinder (12) via a spline.

3. The current transformer with high clamping strength according to claim 1, characterized in that: The release unit (36) comprises a cover body (37), one end of the cover body (37) is sleeved on the outer circumference of the core tube (23), the other end of the cover body (37) is fixedly connected to the guide plate (32), and a limit ring (38), a disc spring (39), a ball (41), a retaining ring (40) and a linkage ring (42) are arranged inside the cover body (37); the retaining ring (40) is fixedly mounted on the guide plate (32), and the centerline hole of the limit plate (13) is located inside the retaining ring (40); the end of the core tube (23) is fixedly connected to the linkage ring (42), and the linkage ring (42) abuts against the inner top wall of the cover body (37); A plurality of ball return grooves are arranged in an array on the outer periphery of the retaining ring (40), and balls (41) are installed in the ball return grooves. Ball positioning grooves are provided on the linkage ring (42) adjacent to the balls (41). A limiting ring (38) is installed on the side of the balls (41) away from the linkage ring (42), and a disc spring (39) is installed on the side of the limiting ring (38) away from the balls (41). Under normal conditions, the limiting ring (38) squeezes the balls (41) into the ball positioning grooves to drive the core tube (23) and the guide plate (32). When the torque is overloaded, the balls (41) are separated from the ball positioning grooves and enter the other end of the ball return grooves to release the transmission.

4. The current transformer with high clamping strength according to claim 1, characterized in that: A limit assembly (49) is arranged between the slide bar (16) and the slide groove (15), and the limit assembly (49) comprises a reset spring (45), a ratchet rod (47) and a reset rod (46); an inclined groove (44) is provided on one side of the slide groove (15), a reset spring (45) and a ratchet rod (47) are installed in the inclined groove (44), and a reset lever (46) is arranged on the ratchet rod (47); a ratchet (43) is arranged on the side wall of the slide bar (16) adjacent to the ratchet rod (47), and a reverse ratchet (48) is arranged at the end of the ratchet rod (47) to match the ratchet (43).

5. The current transformer with high clamping strength according to claim 1, characterized in that: The guide plate (32) is mounted in a housing (24) at one end via a first bearing (21); and the end of the actuator cylinder (12) close to the core tube (23) is mounted in a housing (24) at the other end via a second bearing (22).

6. The current transformer with high clamping strength according to claim 1, characterized in that: A protrusion (14) is provided on the outer periphery of the limiting plate (13), and a groove (25) is provided on the inner wall of the housing (24) adjacent to the limiting plate (13), wherein the protrusion (14) is matched with the groove (25).

7. The current transformer with high clamping strength according to claim 2, characterized in that: The guide hole (28) penetrates the side wall of the guide body (26) and the bottom ring (27), forming guide channels corresponding to each other.

8. The current transformer with high clamping strength according to claim 2, characterized in that: The inner side of the arc-shaped plate (18) is provided with anti-skid grooves, which are distributed in a radial array and are used to increase the contact friction with the cable.

9. The current transformer with high clamping strength according to claim 3, characterized in that: The outer peripheral surface of the cover body (37) is provided with a plurality of evenly distributed ventilation holes.

10. A method for clamping a line using the current transformer according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, insert the cable through the primary side threading hole of the body (11), and pass through the head end clamp and the tail end clamp; S2, the actuator cylinder (12) provided with anti-slip grooves is screwed, and the head end clamp and the tail end clamp are driven to move synchronously through the core tube (23), and at this time, the protrusion (14) of the limit plate (13) is embedded in the groove (25) of the shell (24), so as to prevent the limit plate (13) from rotating with the guide plate (32); S3, the guide plate (32) in the head end clamp drives the guide rod (34) and the slide rod (16) to slide in the slide groove (15) through the arc guide groove (33), and the plurality of slide rods (16) all move toward the center to preferentially clamp the cable, and the ratchet (43) on the side wall of the slide rod (16) cooperates with the reverse ratchet (48) at the end of the ratchet rod (47) to prevent the slide rod (16) from moving in the reverse direction; S4. When the head-end clamp reaches a predetermined clamping force, the ball (41) in the release unit (36) disengages from the ball positioning groove of the linkage ring (42) under the action of the disc spring (39), interrupting the power transmission of the core tube (23) to the guide plate (32). At the same time, the ratchet rod (47) in the limit assembly (49) engages with the ratchet teeth (43) of the slide rod (16), locking the cable clamping position; S5. The tail end clamp continues to operate, and the helical tooth plate (29) cooperates with the internal thread (35) of the guide ring (19) to drive the arc plate (18) provided with radial array anti-slip grooves to clamp the other end of the cable, and generates an outward thrust during the clamping process to keep the cable in a straight state, thereby ensuring that the cable is in a central position in the current transformer.

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