Clip-on ammeter for residual current detection

Abstract

The invention relates to the technical field of clip-on ammeters, in particular to a clip-on ammeter for residual current detection, which comprises a residual current handheld meter body and a residual current sensor, and a connecting wire is arranged between the residual current handheld meter body and the residual current sensor. The structure of a fixed annular jaw and the structure of a movable annular jaw are optimally designed, a jaw closing mechanism is integrated at the closed position of the end of the jaw and combined with a negative pressure attaching assembly, it is ensured that the jaws are completely and tightly attached when closed, and the problems that tiny gaps exist, consequently, a magnetic circuit is incomplete, and the uniformity and measurement precision of a magnetic field are affected are solved; and the annular protective cover plate is matched with the inner side tong head magnetic core mechanism, so that gap compensation at the magnetic core mounting cavities on the inner sides of the fixed annular jaw and the movable annular jaw is met, mounting protection of the magnetic core assembly can be achieved, and auxiliary heat dissipation of the magnetic core assembly in the working state can be assisted.

Description

Technical Field

[0001] This invention relates to the field of clamp ammeter technology, specifically to a clamp ammeter for residual current detection. Background Technology

[0002] Residual current detection is crucial in the operation and maintenance of power systems. Residual current may be caused by damage to the insulation of electrical equipment, leakage in lines, etc. If it is not detected and dealt with in time, it may cause safety hazards such as electrical fires and electric shock accidents. Traditional current detection methods have many inconveniences when dealing with residual current detection. For example, it is necessary to disconnect the circuit for detection, which not only affects the normal power supply, but also increases the complexity of operation and safety risks. Therefore, clamp ammeters have been widely used in the field of residual current detection because they can detect current without disconnecting the circuit. They can quickly and conveniently detect the circuit in operation, promptly detect potential leakage problems, and ensure the safe and stable operation of the power system.

[0003] In the prior art, such as the residual current detection device with convenient detection method disclosed in CN210181114U, a switch is provided on the side wall of the housing. The switch is electrically connected to the circuit board. The switch has a first position and a second position. When the switch is switched to the first position, the detection jaws are working. When the switch is switched to the second position, the Rogowski coil is working. This allows the detection jaws and the Rogowski coil of the residual current detection device to work independently. That is, the residual current detection device has two detection functions, which greatly improves the versatility of the residual current detection device and can also greatly improve the detection convenience of the clamp ammeter and the maintenance convenience of maintenance personnel.

[0004] However, in actual use, the existing fixed clamp and movable clamp structures are simple. Under long-term opening and closing operations, the jaws are prone to wear, which cannot guarantee a completely tight fit when closed. There are small gaps, resulting in an incomplete magnetic circuit, affecting the uniformity of the magnetic field and the detection accuracy. Moreover, when the magnetic core assembly is working, the coil wound on the surface generates heat due to resistance after being energized. Traditional jaws have difficulty dissipating this heat, which causes the magnetic core to be in a high-temperature state, affecting the service life of the clamp ammeter.

[0005] Therefore, this invention proposes a clamp-on ammeter for residual current detection to solve the problem that existing clamp-on ammeters have a simple structure and cannot guarantee a completely tight fit when closed, resulting in an incomplete magnetic circuit. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a clamp ammeter for residual current detection, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a clamp-on ammeter for residual current detection, comprising a residual current handheld meter body and a residual current sensor, wherein a wiring is provided between the residual current handheld meter body and the residual current sensor, and the residual current sensor comprises a body mounting mechanism and a clamp head magnetic core mechanism, wherein the body mounting mechanism comprises a mounting housing one, a mounting housing two, a fixed annular jaw, and a movable annular jaw, wherein the fixed annular jaw and the movable annular jaw are disposed inside the mounting housing one and the mounting housing two, and the lower end of the movable annular jaw is rotatably connected to the fixed annular jaw via a pin; the clamp head magnetic core mechanism comprises a magnetic core assembly, a magnetic core mounting bracket, a Hall element, and fastening fasteners, wherein two sets of magnetic core assemblies are provided and respectively disposed inside the fixed annular jaw and the movable annular jaw; a magnetic core mounting cavity is provided on the inner wall of both the fixed annular jaw and the movable annular jaw, and a magnetic core protection mechanism is provided on the inner side of the magnetic core mounting cavity, wherein the magnetic core protection mechanism comprises an annular protective cover and a negative pressure bonding assembly.

[0008] Preferably, the upper ends of the fixed annular jaws and the movable annular jaws are provided with a jaw closing mechanism. The jaw closing mechanism includes a connecting plate, which is fixedly installed at the upper end joint of the fixed annular jaws and the movable annular jaws. A connecting guide gap is provided on the inner side of the connecting plate.

[0009] Preferably, the jaw closing mechanism further includes a guide post, which is fixedly installed at the end of the movable annular jaw away from the jaw trigger. A V-shaped frame is fixedly connected to one outer surface of the guide post, and a guide contact wheel is rotatably installed at the other end of the V-shaped frame. The outer surface of the guide contact wheel movably abuts against the inner wall of the connecting guide gap.

[0010] Preferably, the annular protective cover is provided in four sets, with each set of two annular protective covers forming a group and distributed in parallel on both sides of the fixed annular jaw and the movable annular jaw by bolts. The negative pressure bonding component includes a negative pressure channel and an arc-shaped contact bag. The outer surface of the arc-shaped contact bag away from the negative pressure channel is in movable contact with the outer surface of the guide post. The negative pressure channel penetrates the inner wall of the annular protective cover, and a miniature vacuum pump is provided at the input end of the negative pressure channel. The miniature vacuum pump is fixedly installed on the outer surface of the annular protective cover, and the output end of the negative pressure channel is fixedly connected to the side of the arc-shaped contact bag away from the guide post.

[0011] Preferably, negative suction holes are evenly formed on the inner wall of the arc-shaped contact bag near the guide post, and an elastic element is fixedly installed on the inner wall of the arc-shaped contact bag.

[0012] Preferably, parallel connecting components are provided on both sides of the arc-shaped contact bag. The parallel connecting components include an outer guide side plate and an inner protective side plate. The outer guide side plate and the inner protective side plate are respectively fixedly connected to the upper end of the annular protective cover plate. A guide groove is formed on the inner surface of the outer guide side plate. The inner surface of the guide groove is movably connected to the outer surface of the guide post.

[0013] Preferably, both the fixed annular jaw and the movable annular jaw have filling grooves on their inner annular surfaces. The inner surface of the filling groove is movably engaged with the outer surface of the Hall element. The Hall element has a "T"-shaped plate structure in its top view cross-section. The inner surface of the Hall element is movably abutting against one side surface of the magnetic core mounting bracket.

[0014] Preferably, the fastening bolt penetrates the inner wall of the Hall element and the magnetic core mounting bracket and is threaded to them. The fastening bolt has a central hole on its inner surface, and the inner wall of the central hole is staggered with drying plates.

[0015] Preferably, the inner surface of the magnetic core mounting bracket has a U-shaped groove structure, and the inner surface of the magnetic core mounting bracket is movably engaged with the outer surface of the magnetic core assembly. The inner wall of the magnetic core mounting bracket has an annular channel and a side channel, and the annular channel and the side channel are interconnected. The inner surface of the side channel is movably fitted with a thermally conductive filler plate, and the inner surface of the thermally conductive filler plate is movably in contact with the outer surface of the magnetic core assembly.

[0016] Preferably, the inner end of the fastening bolt is provided with a flow hole, which is connected to the central hole. The flow hole is connected to the input end of the annular channel, and the output end of the annular channel is provided with a C-shaped groove.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention proposes a clamp meter for residual current detection. Through optimized design of the fixed and movable annular jaws, a jaw closure mechanism is integrated at the jaw end closure point and combined with a negative pressure bonding component. This ensures a completely tight fit when the jaws are closed, avoiding any tiny gaps that could lead to incomplete magnetic circuits, affecting magnetic field uniformity and measurement accuracy. Furthermore, the annular protective cover cooperates with the inner jaw core mechanism to compensate for gaps in the inner core mounting cavity of both the fixed and movable annular jaws, providing protection for the core assembly and assisting in heat dissipation during operation. Additionally, the addition of a Hall element further enhances the accuracy and safety of residual current detection. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the connection structure between the residual current handheld meter body and the residual current sensor of the present invention. Figure 2 This is a three-dimensional structural schematic diagram of the residual current sensor of the present invention; Figure 3 For the present invention Figure 2 A schematic diagram of the cross-sectional structure at point aa; Figure 4 For the present invention Figure 3 A magnified structural diagram at point A; Figure 5 For the present invention Figure 2 A schematic diagram of the cross-sectional structure at point bb; Figure 6 For the present invention Figure 5 A magnified structural diagram at point B; Figure 7 This is a schematic diagram of the disassembly structure of the main body mounting mechanism of the present invention; Figure 8 This is a schematic diagram of the fixed annular jaws and the movable annular jaws in their open states according to the present invention; Figure 9 For the present invention Figure 9 A magnified structural diagram at point C; Figure 10 This is a schematic diagram of the magnetic core protection mechanism and the mounting structure of the fixed and movable annular jaws of the present invention; Figure 11 For the present invention Figure 10 Schematic diagram of the dismantling structure of the core protection mechanism; Figure 12 This is a schematic diagram of the disassembly structure of the fixed annular jaws and the annular protective cover plate of the present invention; Figure 13 For the present invention Figure 12 A magnified structural diagram at point D; Figure 14 This is a schematic diagram of the mounting structure of the fixed annular jaws and jaw magnetic core mechanism of the present invention; Figure 15 This is a schematic diagram of the connection structure between the magnetic core protection mechanism and the clamp head magnetic core mechanism of the present invention; Figure 16 For the present invention Figure 15 A schematic diagram of the cross-sectional structure at the cc point; Figure 17 This is a schematic diagram of the connection structure between the magnetic core mounting bracket and the Hall element of the present invention; Figure 18 For the present invention Figure 17 A schematic diagram of the cross-sectional structure at point dd; Figure 19 For the present invention Figure 18A magnified structural diagram at point E; Figure 20 This is a schematic diagram showing the disassembled structure of the magnetic core mounting bracket and Hall element of the present invention.

[0019] In the diagram: 1. Residual current handheld meter body; 11. Antenna; 12. Wiring; 2. Residual current sensor; 20. Receiving slot; 21. Mounting housing one; 22. Mounting housing two; 23. Fixed annular jaws; 230. Magnetic core mounting cavity; 231. Connecting plate; 2300. Connecting guide gap; 24. Movable annular jaws; 240. Guide post; 2401. V-frame; 2402. Guide contact wheel; 241. Clamping head trigger; 242. Spring; 3. Annular protective cover; 31. Negative pressure channel; 32. Arc-shaped contact bag; 320. Negative suction hole; 33. Elastic element; 30. Outer guide side plate; 300. Guide groove; 301. Inner protective side plate; 4. Magnetic core assembly; 41. Magnetic core mounting bracket; 410. Annular channel; 4101. Side channel; 4102. C-shaped groove; 411. Thermally conductive filler plate; 42. Hall element; 43. Fastening bolt; 430. Flow hole; 431. Staggered drying plate. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1, please refer to Figures 1-20This invention provides a technical solution: a clamp-on ammeter for residual current detection, comprising a residual current handheld meter body 1 and a residual current sensor 2. A wiring 12 is provided between the residual current handheld meter body 1 and the residual current sensor 2. An antenna 11 is fixedly connected to the upper end of the residual current handheld meter body 1 via an antenna interface. The wiring 12 is fixedly connected to the residual current handheld meter body 1 via a BNC interface. The antenna interface is used to connect the antenna in wireless communication mode to improve signal strength. The BNC interface is used to connect the residual current sensor 2. The residual current sensor 2 includes a body mounting mechanism and a clamp head magnetic core mechanism. The body mounting mechanism consists of a mounting housing 1 21, a mounting housing 22, a fixed annular clamp jaw 23, and... The movable annular jaws 24 are composed of a mounting housing 1 21, a mounting housing 22, a fixed annular jaw 23, and a movable annular jaw 24, all of which are made of ABS injection-molded flame-retardant housings, which are waterproof, dustproof, and impact-resistant. The fixed annular jaws 23 and the movable annular jaws 24 are located inside the mounting housing 1 21 and the mounting housing 22, respectively. The lower end of the movable annular jaws 24 is rotatably connected to the fixed annular jaws 23 via a pin. When the mounting housing 1 21 and the mounting housing 22 are assembled, a receiving groove 20 is formed on one side. A jaw trigger 241 is fixedly connected to the lower end of the movable annular jaws 24. A spring 242 is movably abutted against the inner side of the jaw trigger 241, and the outer surface of the end of the spring 242 away from the spring 242 is fixedly connected to the inner wall of the receiving groove 20. The clamp head magnetic core mechanism consists of a magnetic core assembly 4, a magnetic core mounting bracket 41, a Hall element 42, and a fastening bolt 43. The magnetic core assembly 4 is provided in two sets and is respectively located inside the fixed annular jaw 23 and the movable annular jaw 24. Both the fixed annular jaw 23 and the movable annular jaw 24 have magnetic core mounting cavities 230 on their inner walls. A magnetic core protection mechanism is provided on the inner side of the magnetic core mounting cavity 230. The magnetic core protection mechanism includes an annular protective cover plate 3 and a negative pressure bonding component. A jaw closing mechanism is provided at the upper ends of the fixed annular jaw 23 and the movable annular jaw 24. The jaw closing mechanism includes a connecting plate 231, which is fixedly installed at the upper end joint of the fixed annular jaw 23 and the movable annular jaw 24. A connecting guide gap 2300 is provided on the inner side of the connecting plate 231. The jaw closing mechanism also includes a guide post 240, which is fixedly installed at the end of the movable annular jaw 24 away from the jaw trigger 241. A V-shaped frame 2401 is fixedly connected to one outer surface of the guide post 240, and a guide contact wheel 2402 is rotatably installed at the other end of the V-shaped frame 2401. The outer surface of the guide contact wheel 2402 is in contact with the inner wall of the connecting guide gap 2300. In this embodiment, refer to Figure 8 The image shows the fixed annular jaw 23 and the movable annular jaw 24 in an open state. Figure 10In the closed state, when the fixed annular jaws 23 and 24 are fully closed, a wire-passing hole is formed in the center. When the residual current sensor 2 is held as a whole, the thumb presses the jaw trigger 241 inward, causing the spring 242 to compress inward. Under the action of the pin, the movable annular jaws 24 open outward, forming an opening at the interface with the fixed annular jaws 23. When detecting the residual current of a certain line, the wire is inserted through the opening of the fixed annular jaws 23 and the movable annular jaws 24. Then, the jaw trigger 241 is released, releasing the pressing state. The movable annular jaw 24 returns to its closed state with the fixed annular jaw 23 under the reverse elastic force of the spring 242. At this time, the line is between the wire holes, and the magnetic core assembly 4 inside the fixed annular jaw 23 and the movable annular jaw 24 forms a complete magnetic circuit. The Hall element 42 integrated and installed inside the fixed annular jaw 23 and the movable annular jaw 24 in parallel can further enhance the accuracy of residual current detection, quickly respond to changes in magnetic field, and improve the ability of the residual current sensor 2 to capture transient currents. It should be noted that, as Figure 5 As shown, a cable tray is provided at the lower end of the fixed annular jaw 23, and a cable is provided inside the cable tray for power connection of the fixed annular jaw 23 and the magnetic core assembly 4 inside the movable annular jaw 24. When the fixed annular jaw 23 and the movable annular jaw 24 are opening and closing, the guide contact wheel 2402 at the closed jaw of the movable annular jaw 24 rolls on the inner wall of the connecting guide gap 2300. By using rolling friction instead of direct friction, the frictional resistance during closure can be reduced, avoiding difficulties in opening and closing. The V-shaped frame 2401 here is a high-strength elastic structure that can undergo slight elastic deformation when closed, ensuring that it supports the inner wall of the connecting guide gap 2300 in the closed state, avoiding incomplete closure that could lead to an incomplete magnetic circuit.

[0022] Example 2, see attached document Figures 1-20 Based on Embodiment 1, in order to achieve a completely tight fit between the fixed annular jaw 23 and the movable annular jaw 24 at the jaw closure point, and to avoid the existence of tiny gaps that could lead to an incomplete magnetic circuit, affecting the uniformity of the magnetic field and the measurement accuracy: Four sets of annular protective covers 3 are provided, with each set of two annular protective covers 3 forming a group and being bolted parallel to each other on both sides of the fixed annular jaw 23 and the movable annular jaw 24. The negative pressure bonding component includes a negative pressure channel 31 and an arc-shaped contact bladder 32. The outer surface of the arc-shaped contact bladder 32 away from the negative pressure channel 31 is in contact with the outer surface of the guide post 240. The negative pressure channel 31 penetrates the inner wall of the annular protective cover 3, and a miniature vacuum pump is provided at the input end of the negative pressure channel 31. The miniature vacuum pump is fixedly installed on the outer surface of the annular protective cover 3. The output end of the negative pressure channel 31 is fixedly connected to the side of the arc-shaped contact bladder 32 away from the guide post 240. Negative suction holes 320 are evenly opened on the inner wall of the arc-shaped contact bladder 32 near the guide post 240, and an elastic element 33 is fixedly installed on the inner cavity side wall of the arc-shaped contact bladder 32. In this embodiment, refer to Figure 3 , Figure 4 , Figure 16 As shown, a negative pressure fitting component is integrated inside the annular protective cover plate 3 to ensure that the jaws are completely and tightly fitted when closed, avoiding any tiny gaps that could lead to an incomplete magnetic circuit and affect the uniformity of the magnetic field and measurement accuracy. Specifically, when the fixed annular jaw 23 and the movable annular jaw 24 are in the initial closed state, the guide post 240 abuts against the arc-shaped contact bag 32. Here, a sensor is installed on the surface of the arc-shaped contact bag 32 near the guide post 240. When the guide post 240 contacts the sensor, the negative pressure suction system is activated, and the micro vacuum pump responds quickly, initiating negative pressure suction on the arc-shaped contact bag 32 through the negative pressure channel 31. At this time, the guide post 240 is tightly attracted to the surface of the arc-shaped contact bag 32 under the action of multiple negative suction holes 320, thus achieving complete fitting of the fixed annular jaw 23 and the movable annular jaw 24 when closed, avoiding any tiny gaps. It is worth noting that the arc-shaped contact bag 32 can also weaken the impact of the guide post 240 when closed, further extending the overall service life of each component.

[0023] Example 3, refer to Appendix Figures 1-20 Based on Embodiment 2, this embodiment adds a parallel connection component: Parallel connecting components are provided on both sides of the arc-shaped contact bag 32. The parallel connecting components include an outer guide side plate 30 and an inner protective side plate 301. The outer guide side plate 30 and the inner protective side plate 301 are respectively fixedly connected to the upper end of the annular protective cover plate 3. A guide groove 300 is provided on the inner surface of the outer guide side plate 30. The inner surface of the guide groove 300 is movably connected to the outer surface of the guide post 240. In this embodiment, refer to Figure 12 , Figure 13 , Figure 14 and Figure 15As shown, the two sets of annular protective covers 3 compensate for the gaps on both sides of the fixed annular jaw 23, and also meet the installation requirements of the magnetic core assembly 4. Here, by setting parallel connecting components near the interface between the annular protective cover 3 and the movable annular jaw 24, the parallel distributed outer guide side plate 30 and inner protective side plate 301 can not only ensure the guidance when the fixed annular jaw 23 and the movable annular jaw 24 are closed, but also meet the protection effect of the inner arc-shaped contact bag 32. In addition, the setting of the inner protective side plate 301 further enhances the tightness of the guide post 240 and the arc-shaped contact bag 32 when they are in contact, avoiding the situation of negative pressure failure, and can also block and protect the magnetic circuit connection port of the magnetic core assembly 4, thus achieving the effect of "one thing serving multiple purposes".

[0024] Example 4, see attached document Figures 1-20 Based on Embodiment 3, in order to achieve the compatible installation of Hall element 42 with fixed annular jaw 23 and movable annular jaw 24, and to suppress external electromagnetic interference: Both the fixed annular jaw 23 and the movable annular jaw 24 have filling grooves on their inner annular surfaces. The inner surface of the filling grooves is movably engaged with the outer surface of the Hall element 42. The Hall element 42 has a "T"-shaped plate structure in its top view. The inner surface of the Hall element 42 is movably abutting against one side surface of the magnetic core mounting bracket 41. The fastening bolt 43 penetrates the inner wall of the Hall element 42 and the magnetic core mounting bracket 41 and is threadedly connected to them. In this embodiment, a filling groove is opened on the inner ring sidewall of the fixed annular jaw 23 and the movable annular jaw 24 for matching and mounting the Hall element 42. This expands the application range of the residual current sensor 2, enables rapid response to changes in the magnetic field, and further enhances the ability of the residual current sensor 2 to capture transient currents. The fastening bolt 43 acts as a locking element to ensure quick and tight mounting of the magnetic core mounting bracket 41 and the Hall element 42, and facilitates maintenance.

[0025] Example 5, see attached document Figures 1-20 Based on Embodiment 4, in order to extend the overall service life of the residual current sensor 2 and the magnetic core assembly 4, and to avoid the reduction of the magnetic permeability of the magnetic core assembly 4 due to high temperature, which would affect the accuracy of the residual current sensor 2: The fastening bolt 43 has a central hole on its inner surface, and the inner wall of the central hole is staggered with drying plates 431. The inner surface of the magnetic core mounting bracket 41 has a U-shaped groove structure. The inner surface of the magnetic core mounting bracket 41 is movably engaged with the outer surface of the magnetic core assembly 4. The inner wall of the magnetic core mounting bracket 41 has an annular channel 410 and a side channel 4101, which are interconnected. The inner surface of the side channel 4101 is movably engaged with a heat-conducting filler plate 411, and the inner surface of the heat-conducting filler plate 411 is in movable contact with the outer surface of the magnetic core assembly 4. The fastening bolt 43 has a flow hole 430 at one inner end, which is interconnected with the central hole. The flow hole 430 is connected to the input end of the annular channel 410, and the output end of the annular channel 410 has a C-shaped groove 4102. In this embodiment, refer to Figure 5 , Figure 6 , Figures 17-19 As shown, when the annular protective covers 3 on both sides of the fixed annular jaw 23 and the movable annular jaw 24 are not installed, the magnetic core mounting bracket 41 is first installed on the outside of the magnetic core assembly 4 and positioned inside the magnetic core mounting cavity 230. At this time, the position of the magnetic core mounting bracket 41 needs to correspond one-to-one with the position of the filling groove. Then, each Hall element 42 is inserted into the filling groove corresponding to the position of the magnetic core mounting bracket 41 for limiting, and the fastening bolt 43 is used for threaded installation to lock the magnetic core mounting bracket 41 and the Hall element 42. It is worth noting that the fastening bolt 43 here is a hollow rod, and the center hole is provided with staggered drying plates 431, which can remove dust and water from the outside. While the flow is partially blocked, it does not affect the airflow. When the air reaches the flow hole 430, it connects with the annular channel 410 through the flow hole 430. This allows for heat exchange between the external air and the magnetic core mounting bracket 41, preventing heat accumulation in the magnetic core assembly 4 during operation and thus avoiding the problem of affecting the accuracy of residual current detection, further improving safety performance. It is also worth noting that a heat-conducting filler plate 411 is installed on the inner wall of the side channel 4101. The heat-conducting filler plate 411 is tightly attached to both sides of the magnetic core assembly 4, achieving heat exchange while also increasing the tightness of the installation between the magnetic core mounting bracket 41 and the magnetic core assembly 4, improving the stability of the magnetic circuit connection.

[0026] The working principle and usage process of this invention are as follows: In actual use, firstly, press and hold the power button on the residual current handheld meter body 1 for three seconds to turn it on. Connect the antenna 11. Select a residual current sensor 2 with an appropriate range and size as needed. Insert the BNC connector of the residual current sensor 2 into the interface of the residual current handheld meter body 1 and lock it. When performing residual current detection of the line, hold the residual current sensor 2 as a whole and press the clamp trigger 241 inward with your thumb, causing the spring 242 to compress inward. Under the action of the pin, the movable annular jaw 24 opens outward, engaging with... An opening is formed at the interface of the fixed annular jaw 23. The wire is inserted through the opening of the fixed annular jaw 23 and the movable annular jaw 24. Then, the jaw trigger 241 is released, releasing the pressing state. The movable annular jaw 24 returns to the closed state with the fixed annular jaw 23 under the reverse elastic force of the spring 242. At this time, the wire is between the wire holes, and the magnetic core assembly 4 inside the fixed annular jaw 23 and the movable annular jaw 24 forms a complete magnetic circuit. When the wire of the circuit under test passes through the jaw, the sensor inside the clamp meter will be cut by the alternating magnetic field. This generates an induced electromotive force (EMF), the magnitude of which is related to the magnetic field strength, the length of the wire, and the current flowing through it. By converting the induced EMF into a digital signal and displaying it on the screen, the magnitude of the current in the circuit under test can be obtained. When the fixed annular jaws 23 and the movable annular jaws 24 are in the initial closed state, the guide post 240 abuts against the arc-shaped contact bag 32. Here, a sensor is installed on the surface of the arc-shaped contact bag 32 near the guide post 240. When the guide post 240 contacts the sensor, the negative pressure suction system is activated, and the miniature vacuum pump responds quickly. The negative pressure channel 31 initiates negative pressure suction on the arc-shaped contact bag 32. At this time, the guide post 240 is attracted to the surface of the arc-shaped contact bag 32 by the action of multiple negative suction holes 320. This achieves complete fit between the fixed annular jaw 23 and the movable annular jaw 24 when they are closed, avoiding any tiny gaps. Furthermore, while detecting residual current, the Hall element 42 installed on the inner ring side of the fixed annular jaw 23 and the movable annular jaw 24 can further enhance the accuracy of residual current detection, quickly respond to changes in magnetic field, and improve the ability of the residual current sensor 2 to capture transient currents.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A clamp-on ammeter for residual current detection, comprising a residual current handheld ammeter body (1) and a residual current sensor (2), wherein a wiring (12) is provided between the residual current handheld ammeter body (1) and the residual current sensor (2), characterized in that: The residual current sensor (2) includes a body mounting mechanism and a clamping head magnetic core mechanism. The body mounting mechanism consists of a mounting housing one (21), a mounting housing two (22), a fixed annular jaw (23), and a movable annular jaw (24). The fixed annular jaw (23) and the movable annular jaw (24) are located inside the mounting housing one (21) and the mounting housing two (22). The lower end of the movable annular jaw (24) is rotatably connected to the fixed annular jaw (23) by a pin. The clamping head magnetic core mechanism consists of a magnetic core... The magnetic core assembly (4), magnetic core mounting bracket (41), Hall element (42) and fastening bolt (43) are composed of a core assembly (4), a magnetic core mounting bracket (41), a Hall element (42) and a fastening bolt (43). The magnetic core assembly (4) is provided with two sets and is respectively located inside the fixed annular jaw (23) and the movable annular jaw (24). The inner walls of the fixed annular jaw (23) and the movable annular jaw (24) are provided with magnetic core mounting cavities (230). The magnetic core mounting cavity (230) is provided with a magnetic core protection mechanism, which includes an annular protective cover plate (3) and a negative pressure bonding component.

2. A clamp-on ammeter for residual current detection according to claim 1, characterized in that: The upper ends of the fixed annular jaw (23) and the movable annular jaw (24) are provided with jaw closing mechanisms. The jaw closing mechanism includes a connecting plate (231). The connecting plate (231) is fixedly installed at the upper end joint of the fixed annular jaw (23) and the movable annular jaw (24). A connecting guide gap (2300) is provided on the inner side of the connecting plate (231).

3. A clamp meter for residual current detection according to claim 2, characterized in that: The jaw closing mechanism further includes a guide post (240), which is fixedly installed at one end of the movable annular jaw (24) away from the jaw trigger (241). A V-shaped bracket (2401) is fixedly connected to one outer surface of the guide post (240), and a guide contact wheel (2402) is rotatably installed at the other end of the V-shaped bracket (2401). The outer surface of the guide contact wheel (2402) is in contact with the inner wall of the connecting guide gap (2300).

4. A clamp meter for residual current detection according to claim 3, characterized in that: The annular protective cover (3) is provided in four sets. Every two sets of the annular protective cover (3) are arranged as a group and are distributed in parallel on both sides of the fixed annular jaw (23) and the movable annular jaw (24) by bolts. The negative pressure bonding component includes a negative pressure channel (31) and an arc-shaped contact bag (32). The outer surface of the arc-shaped contact bag (32) away from the negative pressure channel (31) is in contact with the outer surface of the guide post (240). The negative pressure channel (31) penetrates the inner wall of the annular protective cover (3). A micro vacuum pump is provided at the input end of the negative pressure channel (31). The micro vacuum pump is fixedly installed on the outer surface of the annular protective cover (3). The output end of the negative pressure channel (31) is fixedly connected to the side of the arc-shaped contact bag (32) away from the guide post (240).

5. A clamp-on ammeter for residual current detection according to claim 4, characterized in that: The arc-shaped contact bag (32) has negative suction holes (320) evenly opened on the inner wall of the side near the guide post (240), and an elastic element (33) is fixedly installed on the inner wall of the arc-shaped contact bag (32).

6. A clamp meter for residual current detection according to claim 5, characterized in that: On both sides of the arc-shaped contact capsule (32), there are parallel connection components, which include an outer guiding side plate (30) and an inner protective side plate (301). The outer guiding side plate (30) and the inner protective side plate (301) are respectively fixedly connected to the upper end of the annular protective cover plate (3). On the inner surface of the outer guiding side plate (30), there is a guiding groove (300), and the inner surface of the guiding groove (300) is movably connected to the outer surface of the guiding column (240).

7. A clamp-on ammeter for residual current detection according to claim 1, characterized in that: On the inner ring surfaces of the fixed annular jaw (23) and the movable annular jaw (24), there are filling grooves. The inner surface of the filling groove is movably clamped with the outer surface of the Hall element (42). The top view cross-section of the Hall element (42) is a "T"-shaped plate structure. The inner side surface of the Hall element (42) is movably abutted against one side surface of the magnetic core mounting bracket (41).

8. A clamp meter for residual current detection according to claim 7, characterized in that: The fastening bolt (43) penetrates through the inner walls of the Hall element (42) and the magnetic core mounting bracket (41) and is threadedly connected thereto. In the central inner surface of the fastening bolt (43), there is a central hole, and staggered drying sheets (431) are distributed in a staggered manner on the inner wall of the central hole.

9. A clamp-on ammeter for residual current detection according to claim 8, characterized in that: The inner surface of the magnetic core mounting bracket (41) is a "U"-shaped groove structure. The inner surface of the magnetic core mounting bracket (41) is movably clamped with the outer surface of the magnetic core assembly (4). An annular channel (410) and a side channel (4101) are provided on the inner wall of the magnetic core mounting bracket (41), and the annular channel (410) and the side channel (4101) are mutually connected. A heat-conducting filling sheet (411) is movably clamped on the inner surface of the side channel (4101), and the inner surface of the heat-conducting filling sheet (411) is respectively movably contacted with the outer surface of the magnetic core assembly (4).

10. A clamp meter for residual current detection according to claim 9, characterized in that: At the inner end of the fastening bolt (43), there is a flow round hole (430), and the flow round hole (430) is mutually connected with the central hole. The flow round hole (430) is对接 with the input end of the annular channel (410), and a C-shaped groove (4102) is provided at the output end of the annular channel (410).

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