Load switch for intelligent electric meter

Abstract

The utility model relates to a load switch for an intelligent electric meter, which comprises a shell, a null line assembly, a live wire assembly, a driving mechanism, a closing mechanism and an isolating mechanism are arranged in the shell, the driving mechanism controls the opening and closing of the closing mechanism, the isolating mechanism is used for isolating the null line assembly and the live wire assembly, and the live wire assembly comprises a first connecting plate and a second connecting plate which are separated from each other. The switching-on mechanism comprises a first rotating shaft arranged on the shell, a rotating shaft support arranged on the first rotating shaft, a moving contact arranged on the rotating shaft support, a cam assembly driving the rotating shaft support to rotate around the first rotating shaft, a reset piece limiting rotation of the rotating shaft support, and a static contact arranged on the second connecting plate. The moving contact is electrically connected with the first connecting plate. According to the utility model, the cam assembly is used to maintain the abutting of the moving contact and the static contact, the abutting stability of the moving contact and the static contact is improved, when the load circuit is disconnected, the cam assembly and the reset member cooperate to realize the rapid separation of the moving contact and the static contact, the generation of electric arc is reduced, and the safety is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of load switches, in particular to a load switch for an intelligent electric meter. Background Art

[0002] Smart meters with built-in load switches are widely used in various power management systems, particularly in scenarios requiring remote control and management. For example, in smart grids, power providers can use smart meters with built-in load switches to monitor and remotely control user electricity usage in real time, thereby improving the efficiency and safety of power management.

[0003] However, the load switch has the following problems when in use: when the load switch disconnects the load circuit, the disengagement speed of the moving contact and the static contact cannot meet the requirements, and the arc between the moving contact and the static contact cannot be extinguished quickly, resulting in burning of the moving and static contacts.

[0004] Therefore, there is a need for a load switch for smart meters that can achieve rapid separation of a moving contact and a static contact, reduce arc generation, improve safety, and has a simple structure and low cost. Utility Model Content

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a load switch for a smart electric meter.

[0006] The technical solution of this utility model is as follows:

[0007] A load switch for a smart meter, comprising a housing, wherein a neutral wire assembly, a live wire assembly, a drive mechanism, a closing mechanism, and an isolation mechanism are disposed within the housing, wherein the drive mechanism controls the opening and closing of the closing mechanism, the isolation mechanism is used to isolate the neutral wire assembly from the live wire assembly, the live wire assembly includes a separate first coupling plate and a second coupling plate, the closing mechanism includes a first rotating shaft disposed on the housing, a rotating shaft bracket disposed on the first rotating shaft, a moving contact disposed on the rotating shaft bracket, a cam assembly that drives the rotating shaft bracket to rotate about the first rotating shaft, a reset member that limits the rotation of the rotating shaft bracket, and a static contact disposed on the second coupling plate, wherein the moving contact is electrically connected to the first coupling plate;

[0008] When the circuit breaker is closed, the driving mechanism drives the cam assembly to rotate in a first direction, the cam assembly applies a driving force to the rotating shaft bracket and drives the rotating shaft bracket to rotate, the moving contact moves toward the static contact and abuts against the static contact, and the rotating shaft bracket remains stationary;

[0009] When the switch is opened, the driving mechanism drives the cam assembly to rotate in the second direction, the cam assembly releases the driving force on the rotating shaft bracket, the reset member applies a pulling force to the rotating shaft bracket, and the moving contact moves in a direction away from the static contact to separate the moving contact from the static contact.

[0010] As a further improvement of the present invention, the driving mechanism includes a control board arranged in the housing, a motor controlled by the control board, a worm and a worm wheel arranged at a driving end of the motor, and the worm wheel is engaged with the cam assembly.

[0011] As a further improvement of the present invention, the cam assembly includes a second rotating shaft arranged in the housing, a gear portion arranged on the second rotating shaft, and a cam portion arranged on the gear portion. The gear portion is engaged with the worm gear. When the switch is closed, the cam portion abuts against the rotating shaft bracket and applies driving force to the rotating shaft bracket.

[0012] As a further improvement of the present invention, the rotating shaft bracket includes a main body rotating around the first rotating shaft, and the main body is provided with a connecting hole and a connecting part, the connecting hole is used to be connected to the reset part, and the connecting part abuts against the cam assembly and bears the driving force from the cam assembly.

[0013] As a further improvement of the present invention, there are multiple moving contacts and multiple static contacts, and the number of the moving contacts is the same as that of the static contacts and they correspond one to one.

[0014] As a further improvement of the present invention, an energy storage component is provided between the moving contact and the rotating shaft bracket.

[0015] As a further improvement of the present invention, the isolation mechanism includes a zero-sequence current transformer arranged on the shell and an isolation bracket arranged in the middle of the zero-sequence current transformer, the neutral line assembly includes a third connecting plate, the second connecting plate and the third connecting plate both pass through the zero-sequence current transformer, and the isolation bracket isolates the second connecting plate and the third connecting plate.

[0016] As a further improvement of the present invention, a first through hole is provided on the isolation bracket, a second through hole and a third through hole are respectively provided on both sides of the first through hole, the second connecting plate passes through the second through hole, and the third connecting plate passes through the third through hole.

[0017] As a further improvement of the present invention, the first end of the isolation bracket is provided with a blocking portion extending away from the first through hole, and the blocking portion limits the first end from passing through the zero-sequence current transformer; the second end of the isolation bracket is provided with at least a first limiting portion, and the second connecting plate and / or the third connecting plate are provided with a second limiting portion, and the first limiting portion corresponds to the second limiting portion one by one.

[0018] As a further improvement of the present invention, an arc extinguishing mechanism is provided at the position where the moving contact abuts the static contact.

[0019] According to the utility model of the above solution, the beneficial effects of the utility model are:

[0020] 1. The utility model uses a cam assembly to apply driving force to the rotating shaft bracket to achieve and maintain the abutment between the moving contact and the static contact, thereby improving the stability of the abutment between the two. When the load circuit is disconnected, the cam assembly releases the driving force on the rotating shaft bracket, and under the action of the reset member, the moving contact and the static contact can be quickly separated, reducing the generation of arcs and improving safety.

[0021] 2. The present invention arranges the second connecting plate and the third connecting plate in the second through hole and the third through hole, respectively, so as to achieve a stable distance of the isolation gap between the second connecting plate and the third connecting plate, thereby ensuring a reliable and stable isolation effect. Furthermore, by adding the first through hole, the contact between the neutral wire assembly and the live wire assembly through solid conduction can be reduced, further improving the reliability and stability of the isolation effect.

[0022] 3. The utility model has a simple overall structure, is easy to operate and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of the utility model;

[0024] Figure 2 This is a structural diagram of the closing mechanism of the utility model when it is closed;

[0025] Figure 3 This is a schematic diagram of the structure of the closing mechanism of the utility model when opening;

[0026] Figure 4 This is a structural diagram of the first angle of the rotating shaft bracket of the utility model;

[0027] Figure 5 This is a schematic structural diagram of the second angle of the rotating shaft bracket of the utility model;

[0028] Figure 6 It is a structural diagram of the isolation mechanism of the utility model;

[0029] Figure 7This is a schematic structural diagram of the first angle of the isolation bracket of the utility model;

[0030] Figure 8 This is a schematic structural diagram of the second angle of the isolation bracket of the utility model;

[0031] Figure 9 It is a structural schematic diagram of the second connecting plate of the utility model;

[0032] Figure 10 It is a structural schematic diagram of the shell surface of the utility model;

[0033] Figure 11 It is a structural schematic diagram of the first connecting plate of the utility model.

[0034] In the figure: 1. shell; 21. first connecting plate; 211. L end; 212. JP3 terminal; 213. JP4 terminal; 22. second connecting plate; 23. second limiting portion; 30. first rotating shaft; 31. rotating shaft bracket; 311. main body; 312. connecting hole; 313. connecting portion; 314. slot; 32. moving contact; 33. reset member; 34. static contact; 35. second rotating shaft; 36. gear portion; 37. cam portion; 38. micro switch; 39. torsion spring; 41. control board; 42. motor; 43. worm; 44. worm gear; 51. zero-sequence current transformer; 52. isolation bracket; 53. first through hole; 54. second through hole; 55. third through hole; 56. opening; 57. blocking portion; 58. first limiting portion; 61. third connecting plate; 7. arc extinguishing mechanism. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0036] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] See also Figure 1 The utility model provides a load switch for a smart meter, comprising a housing 1, wherein a neutral wire assembly, a live wire assembly, a driving mechanism, a closing mechanism, and an isolating mechanism are arranged in the housing 1. The driving mechanism controls the opening and closing of the closing mechanism. The isolating mechanism is used to isolate the neutral wire assembly from the live wire assembly. The live wire assembly includes a separate first connecting plate 21 and a second connecting plate 22. The closing mechanism includes a first rotating shaft 30 provided on the housing 1, a rotating shaft bracket 31 provided on the first rotating shaft 30, a moving contact 32 provided on the rotating shaft bracket 31, a cam assembly driving the rotating shaft bracket 31 to rotate around the first rotating shaft 30, a reset member 33 limiting the rotation of the rotating shaft bracket 31, and a static contact 34 provided on the second connecting plate 22. The moving contact 32 is electrically connected to the first connecting plate 21.

[0039] See also Figure 2 When closing the circuit breaker, the cam assembly applies a driving force to the shaft bracket 31, and the moving contact 32 abuts against the static contact 34;

[0040] See also Figure 3 When the switch is opened, the cam assembly releases the driving force on the rotating shaft bracket 31, and the moving contact 32 is separated from the static contact 34. Preferably, the disconnection distance between the moving contact 32 and the static contact 34 reaches about 7 mm.

[0041] The utility model applies a driving force to the rotating shaft bracket 31 through the cam assembly to achieve and maintain the abutment between the moving contact 32 and the static contact 34, thereby improving the stability of the abutment between the two. When the load circuit is disconnected, the cam assembly releases the driving force on the rotating shaft bracket 31, and under the action of the reset member 33, the moving contact 32 and the static contact 34 can be quickly separated, reducing the generation of arcs and improving safety. The overall structure is simple, the operation is convenient, and the cost is low.

[0042] As an embodiment of the present utility model, the driving mechanism includes a control board 41 arranged in the shell 1, a motor 42 controlled by the control board 41, a worm 43 and a worm wheel 44 arranged at the driving end of the motor 42, the worm wheel 44 is engaged with the cam assembly, and the control board 41 is connected to the external signal. The structure of the worm wheel 44 and the worm 43 can reduce the number of parts of the reduction system and simplify the structure to a certain extent. When the fee is in arrears, the control board 41 receives the signal and controls the action of the motor 42, and drives the cam assembly to rotate through the worm 43 and the worm wheel 44 to achieve the separation of the moving contact 32 and the static contact 34 to achieve the purpose of opening the switch. After paying, the control board 41 also receives the signal and controls the action of the motor 42, and drives the cam assembly to rotate through the worm 43 and the worm wheel 44 to achieve the abutment of the moving contact 32 and the static contact 34 to achieve the purpose of closing the switch.

[0043] As an embodiment of the present utility model, the cam assembly includes a second rotating shaft 35 provided in the housing 1, a gear portion 36 provided on the second rotating shaft 35, and a cam portion 37 provided on the gear portion 36. The gear portion 36 is engaged with a driving mechanism in the load switch, and the driving mechanism drives the gear portion 36 to rotate. When the switch is closed, the cam portion 37 abuts against the rotating shaft bracket 31 and applies a driving force to the rotating shaft bracket 31, so that the moving contact 32 and the static contact 34 abut and remain stationary, thereby ensuring stable contact between the moving contact 32 and the static contact 34. When the load circuit is disconnected, the driving mechanism drives the gear portion 36 to rotate in the opposite direction, the cam portion 37 releases the driving force on the rotating shaft bracket 31, and under the action of the reset member 33, the rotating shaft bracket 31 is driven to rotate further, thereby realizing the rapid separation of the moving contact 32 and the static contact 34. Through the structure combined with the gear portion 36 and the cam portion 37, it is only necessary to control the rotation of the gear portion 36 to realize the rotation control of the rotating shaft bracket 31 and the switching of the abutment or separation between the moving contact 32 and the static contact 34. The overall structure is simple and easy to control.

[0044] As an embodiment of the present invention, the center of the gear portion 36 coincides with the center of the cam portion 37, ensuring that the gear portion 36 and the cam portion 37 rotate only around the same center when rotating, which can effectively reduce the overall occupied space and improve space utilization.

[0045] See also Figure 4 and Figure 5As an embodiment of the present invention, the shaft bracket 31 includes a body 311 that rotates around the first shaft 30. The body 311 is provided with a connecting hole 312 and a connecting portion 313. The connecting hole 312 is used to connect with the reset member 33. The reset member 33 transmits the force to the body 311 through the connecting hole 312 to realize the overall rotation of the shaft bracket 31. When the switch is closed, the connecting portion 313 abuts against the cam assembly and bears the driving force from the cam assembly, that is, the driving force of the cam assembly is greater than the force of the reset member 33, realizing the abutment between the moving contact 32 and the static contact 34. When the load is disconnected, When the circuit is closed, the cam assembly releases the driving force on the connecting portion 313, and the shaft bracket 31 rotates only under the force of the reset member 33, thereby realizing the separation between the moving contact 32 and the static contact 34. The connecting hole 312 and the connecting portion 313 are respectively located on both sides of the shaft bracket 31, so that the force from the reset member 33 and the driving force from the cam assembly are mutually opposite forces, and the rotation direction of the shaft bracket 31 is controlled by the magnitude relationship between the two forces, thereby realizing the abutment or separation between the moving contact 32 and the static contact 34. The overall structure is simple and the control is simple, which improves practicality.

[0046] As an embodiment of the present invention, the load switch cam structure also includes a limiter, which limits the rotation of the cam assembly to avoid unnecessary damage caused by endless rotation of the cam assembly, that is, when the load circuit needs to be closed and the moving contact 32 is in contact with the static contact 34, or when the load circuit needs to be disconnected and the moving contact 32 is separated from the static contact 34, the limiter sends a limit signal to stop the cam assembly from moving. Preferably, the limiter is a micro switch 38 provided on the housing 1, and the cam assembly rotates to press or release the micro switch 38, that is, when the load circuit needs to be closed, the drive mechanism drives the cam assembly to rotate to achieve the abutment of the moving contact 32 and the static contact 34, and press the micro switch 38. The micro switch 38 transmits a signal to the drive mechanism to stop the cam assembly from continuing to rotate. When the load circuit needs to be disconnected, the drive mechanism drives the cam assembly to rotate to achieve the separation of the moving contact 32 and the static contact 34, and release the micro switch 38, and the drive mechanism stops the cam assembly from continuing to rotate.

[0047] As an embodiment of the present utility model, there are multiple moving contacts 32 and multiple static contacts 34. The number of moving contacts 32 and the static contacts 34 are the same and correspond one to one. The use of a multi-contact structure can effectively reduce the contact resistance between the moving contact 32 and the static contact 34, reduce temperature rise, increase the service life of the moving contact 32 and the static contact 34, and improve the overall safety of use.

[0048] As an embodiment of the present invention, an energy storage component is provided between the moving contact 32 and the rotating shaft bracket 31. When the moving contact 32 abuts against the static contact 34, the energy storage component stores a certain amount of energy. When the load circuit is disconnected, the energy stored in the energy storage component is released, thereby promoting the rapid separation of the moving contact 32 and the static contact 34. Preferably, the energy storage component is a torsion spring 39. A slot 314 is provided on the rotating shaft bracket 31. The first end of the torsion spring 39 is provided on the rotating shaft bracket 31. The second end of the torsion spring 39 abuts against the moving contact 32 and presses the moving contact 32 into the slot 314. Before the moving contact 32 abuts against the static contact 34, the torsion spring 39 will move The contact 32 is restricted in the slot 314, so that the relative position of the moving contact 32 and the shaft bracket 31 is fixed. After the moving contact 32 abuts against the static contact 34, the shaft bracket 31 continues to rotate, and the moving contact 32 cannot continue to rotate with the shaft bracket 31, causing the torsion spring 39 to be stretched to store energy. When the load circuit is disconnected, the energy stored in the torsion spring 39 is released, so that the moving contact 32 and the static contact 34 are quickly separated. Under the action of the reset member 33, the moving contact 32 and the static contact 34 are further separated, which effectively increases the separation speed of the moving contact 32 and the static contact 34, reduces the generation of arc, and improves safety.

[0049] As an embodiment of the present utility model, the reset member 33 is a tension spring, one end of which is arranged on the housing 1, and the other end of the tension spring is connected to the rotating shaft bracket 31. When the load circuit is closed, the tension force of the tension spring on the rotating shaft bracket 31 is less than the driving force of the cam assembly on the rotating shaft bracket 31. The tension spring is stretched. When the load circuit is disconnected, the cam assembly releases the driving force on the rotating shaft bracket 31, and the tension spring contracts. Under the tension of the tension spring on the rotating shaft bracket 31, the rotating shaft bracket 31 rotates, thereby realizing the separation of the moving contact 32 and the static contact 34.

[0050] See also Figure 6-8, as an embodiment of the present utility model, the isolation mechanism includes a zero-sequence current transformer 51 provided on the housing 1 and an isolation bracket 52 provided in the middle of the zero-sequence current transformer 51, the zero-line assembly includes a third connecting plate 61, the second connecting plate 22 and the third connecting plate 61 both pass through the zero-sequence current transformer 51, the isolation bracket 52 isolates the second connecting plate 22 from the third connecting plate 61, preferably, a first through hole 53 is provided on the isolation bracket 52, and a second through hole 54 and a third through hole 55 are provided on both sides of the first through hole 53, and the second connecting plate 22 passes through the second through hole 53. Through hole 54, the third connecting plate 61 passes through the third through hole 55, and the second connecting plate 22 and the third connecting plate 61 are respectively arranged in the second through hole 54 and the third through hole 55, which can achieve the stability of the distance of the isolation gap between the second connecting plate 22 and the third connecting plate 61, so that the overall creepage distance is stable, and the reliability and stability of the isolation effect are improved. By adding the first through hole 53, the contact between the neutral wire component and the live wire component through solid conduction can be reduced, further improving the reliability and stability of the isolation effect. The overall structure is simple, the installation is convenient, and the use cost is low.

[0051] As an embodiment of the present invention, the second through hole 54 and the third through hole 55 can adopt the following two structures:

[0052] Structure 1: The second through hole 54 and the third through hole 55 are both full holes. During installation, the second connecting plate 22 and the third connecting plate 61 can be inserted into the second through hole 54 and the third through hole 55 in advance. After the second connecting plate 22 and the third connecting plate 61 are assembled with the isolation bracket 52, they are inserted into the zero-sequence current transformer 51 as a whole to complete the assembly;

[0053] Structure 2: The second through hole 54 and / or the third through hole 55 are half holes. Preferably, the second through hole 54 and the third through hole 55 are both half holes. During installation, the second connecting plate 22 and the third connecting plate 61 are preferentially inserted into the zero-sequence current transformer 51, and then the isolation bracket 52 is inserted into the zero-sequence current transformer 51. Finally, the second connecting plate 22 and the third connecting plate 61 are adjusted according to the positions of the second through hole 54 and the third through hole 55 on the isolation bracket 52 to complete the assembly.

[0054] The present invention adopts structure 2. Compared with structure 1, structure 2 can reduce half of the hole wall occupation of the second through hole 54 and the third through hole 55, and convert it into the occupied space of the second through hole 54 and the third through hole 55, effectively expanding the second through hole 54 and the third through hole 55, so that the thickness of the second connecting plate 22 and the third connecting plate 61 allowed to pass through the second through hole 54 and the third through hole 55 is increased, which can effectively increase the overall allowable working current and the overall scope of application, or expand the first through hole 53, so that the interval between the second connecting plate 22 and the third connecting plate 61 becomes larger, thereby improving the isolation effect.

[0055] As an embodiment of the present utility model, the second through hole 54 and the third through hole 55 are symmetrically arranged with respect to the center of the first through hole 53, so that the second through hole 54 and the third through hole 55 can be separated by the farthest distance within the limited space of the isolation bracket 52, thereby ensuring the isolation distance between the second connecting plate 22 and the third connecting plate 61 and improving the isolation effect.

[0056] As an embodiment of the present invention, the first through hole 53 is in the shape of an elongated strip; one long side of the first through hole 53 corresponds to the second through hole 54, and the other long side of the first through hole 53 corresponds to the third through hole 55, which can increase the space between the second through hole 54 and the third through hole 55 as much as possible, so that the thickness of the second connecting plate 22 and the third connecting plate 61 allowed to pass through the second through hole 54 and the third through hole 55 is increased, which can effectively increase the overall allowable working current and improve the overall scope of application.

[0057] As an embodiment of the present invention, an opening 56 is provided on a short side of the first through hole 53 , which can increase the creepage distance between the second connecting plate 22 and the third connecting plate 61 .

[0058] As an embodiment of the present utility model, the first end of the isolation bracket 52 is provided with a blocking portion 57 extending away from the first through hole 53. The blocking portion 57 limits the first end from passing through the zero-sequence current transformer 51. When the isolation bracket 52 is inserted into the zero-sequence current transformer 51 to complete the assembly, the second end of the isolation bracket 52 is preferentially inserted into the zero-sequence current transformer 51. As the isolation bracket 52 is inserted, when the blocking portion 57 contacts the zero-sequence current transformer 51, since the size of the blocking portion 57 is larger than the internal size of the zero-sequence current transformer 51, the blocking portion 57 cannot pass through the zero-sequence current transformer 51, thereby realizing the positioning of the isolation bracket 52 and the zero-sequence current transformer 51 and improving the coordination between the isolation bracket 52 and the zero-sequence current transformer 51.

[0059] As an embodiment of the present invention, there are multiple blocking parts 57. As the use time increases, the blocking parts 57 will be damaged to a greater or lesser extent. The use of multiple blocking parts 57 can prevent the loss of positioning function of the isolation bracket 52 and the zero-sequence current transformer 51 when a certain blocking part 57 is damaged, causing unnecessary impact on the overall isolation effect. Preferably, the multiple blocking parts 57 are evenly arranged, which can make each blocking part 57 evenly stressed, thereby improving the service life of the blocking part 57.

[0060] See also Figure 7-9. As an embodiment of the present invention, the second end of the isolation bracket 52 is provided with at least a first limiting portion 58, and the second connecting plate 22 and / or the third connecting plate 61 is provided with a second limiting portion 23. The first limiting portion 58 corresponds to the second limiting portion 23 one by one. Preferably, the first limiting portion 58 is a snap buckle and the second limiting portion 23 is a protrusion. Through the cooperation of the snap buckle and the protrusion, when the isolation bracket 52 is inserted into the zero-sequence current transformer 51, the snap buckle is clamped on the protrusion, which can limit the isolation bracket 52 from being separated from the second connecting plate 22 or the third connecting plate 61, thereby avoiding the separation of the isolation bracket 52 and the zero-sequence current transformer 51, effectively improving the connection strength between the isolation bracket 52 and the zero-sequence current transformer 51, the second connecting plate 22, and the third connecting plate 61, and improving the overall reliability of use and working stability.

[0061] As an embodiment of the present utility model, the second end is flush with or exceeds the zero-sequence current transformer 51 on a side of the zero-sequence current transformer 51 close to the first limit portion 58, ensuring that the isolation bracket 52 can pass through the interior of the zero-sequence current transformer 51, thereby ensuring that the second connecting plate 22 and the third connecting plate 61 at each position inside the zero-sequence current transformer 51 are effectively isolated by an isolation bracket 52, thereby improving the overall reliability of use and working stability.

[0062] As an embodiment of the present invention, an arc extinguishing mechanism 7 is provided at the position where the moving contact 32 and the static contact 34 abut each other, which can improve the arc extinguishing effect and enhance the overall safety of use. Preferably, the arc extinguishing mechanism 7 adopts an arc extinguishing chamber system.

[0063] See also Figure 10 and Figure 11 As an embodiment of the present invention, the first connecting plate 21 is provided with an L terminal 211, a JP3 terminal 212, and a JP4 terminal 213. Preferably, the JP3 terminal 212 and the JP4 terminal 213 are made of manganese copper material. The L terminal 211, the JP3 terminal 212, and the JP4 terminal 213 all extend out of the housing 1 and are connected to the PCB board of the electric energy meter. The L terminal 211 supplies power to the electric energy meter, and the JP3 terminal 212 and the JP4 terminal 213 are used for current sampling and electric energy metering of the load circuit. At the same time, the zero-sequence current transformer 51 is required to have a wide range to perform recalibration of the load circuit current and sampling of leakage current.

[0064] Technical requirements and key indicators:

[0065] (1) The load switch's rated safe short-time withstand current capability (6000A, 10ms), rated working short-time withstand current capability (3000A, 10ms), and rated short-circuit current capability (3000A, 10ms) shall meet the UC3 test requirements in Table 22 of GB / T17215.231-2021;

[0066] (2) The contact resistance of the load switch should be ≤0.5mΩ;

[0067] (3) After the load switch has undergone the following tests, the opening and closing functions are normal, the switch contact resistance is ≤1.0mΩ, and the live wire in and out should withstand a 2kV withstand voltage test when the switch is disconnected; 150A, ≥8h; 200A, ≥4h;

[0068] (4) Load switch action time: open ≤ 150ms, close ≤ 200ms;

[0069] (5) The electrical gap between the moving contact and the static contact of the load switch shall not be less than 5.5mm; when the load switch is in the off position, the lead-out terminals of the load switch main circuit shall be able to withstand a 6kV impulse withstand voltage;

[0070] (6) The motor drive power consumption (peak value) of the motor-type built-in switch shall not exceed 19.5W (1.3A, 15Vdc, 25ms);

[0071] (7) The mechanical life of the load switch when no-load is not less than 20,000 times; the electrical life when loaded is not less than 10,000 times (electrical life test conditions: 1.5Imax, power factor of 1.0 and 0.5L, the electrical life is not less than 5,000 times);

[0072] (8) When the load switch is passed through a current of 120A, the temperature rise of the main circuit lead-out terminal (terminal) does not exceed 50K, and the temperature rise of the load switch housing surface does not exceed 40K;

[0073] (9) The load switch is closed and a current of 500A is applied. After 3 seconds, the switch is disconnected. This is repeated 10 times on the same load switch, with a 3-minute interval between each test. The contacts of the test sample should not stick. After the test, the sample should be able to perform normal opening and closing operations. The change rate of contact resistance before and after the test should not exceed 50%.

[0074] In summary, the present invention provides a load switch for a smart meter, which applies a driving force to the shaft bracket 31 through the cam assembly to realize and maintain the abutment between the moving contact 32 and the static contact 34, thereby improving the stability of the abutment between the two. When the load circuit is disconnected, the cam assembly releases the driving force on the shaft bracket 31, and under the action of the reset member 33, the moving contact 32 and the static contact 34 can be quickly separated, thereby reducing the generation of arcs and improving safety. The overall structure is simple and the cost is low. The connecting hole 312 and the connecting part 313 are respectively located on both sides of the shaft bracket 31, so that the force from the reset member 33 and the force from the cam assembly are The driving forces of the movable contacts 32 and the stationary contacts 34 are opposite to each other, and the rotation direction of the rotating shaft bracket 31 is controlled by the magnitude relationship between the two forces, thereby realizing the contact or separation between the movable contact 32 and the stationary contact 34. The overall structure is simple and the control is simple, which improves the practicality. The multi-contact structure can effectively reduce the contact resistance between the movable contact 32 and the stationary contact 34, reduce the temperature rise, increase the service life of the movable contact 32 and the stationary contact 34, and improve the overall safety of use. When the movable contact 32 and the stationary contact 34 are in contact, the energy storage component stores a certain amount of energy. When the load circuit is disconnected, the energy stored in the energy storage component is released. The second connecting plate 22 and the third connecting plate 61 are respectively arranged in the second through hole 54 and the third through hole 55, so that the distance of the isolation gap between the second connecting plate 22 and the third connecting plate 61 can be stabilized, so that the overall creepage distance is stable, and the reliability and stability of the isolation effect are improved. The addition of the first through hole 53 can reduce the contact between the neutral wire component and the live wire component through solid conduction, further improving the reliability and stability of the isolation effect. The overall structure is simple, easy to install, and low in cost. The blocking portion 57 cannot pass through the zero-sequence current transformer 51 to achieve The positioning of the isolation bracket 52 and the zero-sequence current transformer 51 improves the coordination between the isolation bracket 52 and the zero-sequence current transformer 51; the multiple blocking parts 57 are evenly arranged, which can make the force on each blocking part 57 uniform, thereby improving the service life of the blocking part 57; through the coordination of the buckle and the protrusion, the isolation bracket 52 can be restricted from being separated from the second connecting plate 22 or the third connecting plate 61, thereby avoiding the separation of the isolation bracket 52 and the zero-sequence current transformer 51, effectively improving the connection strength between the isolation bracket 52 and the zero-sequence current transformer 51, the second connecting plate 22, and the third connecting plate 61, and improving the overall reliability of use and working stability.

[0075] It should be emphasized that the above are only preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A load switch for a smart meter, characterized in that: The invention comprises a housing (1), wherein a neutral line assembly, a live line assembly, a driving mechanism, a closing mechanism and an isolating mechanism are arranged in the housing (1), wherein the driving mechanism controls the opening and closing of the closing mechanism, and the isolating mechanism is used to isolate the neutral line assembly from the live line assembly, wherein the live line assembly comprises a first connecting plate (21) and a second connecting plate (22) which are separated, and wherein the closing mechanism comprises a first rotating shaft (30) arranged on the housing (1), a rotating shaft support (31) arranged on the first rotating shaft (30), a moving contact (32) arranged on the rotating shaft support (31), a cam assembly for driving the rotating shaft support (31) to rotate around the first rotating shaft (30), a reset member (33) for limiting the rotation of the rotating shaft support (31), and a static contact (34) arranged on the second connecting plate (22), wherein the moving contact (32) is electrically connected to the first connecting plate (21); When the switch is closed, the cam assembly applies a driving force to the rotating shaft bracket (31), and the moving contact (32) abuts against the static contact (34); When the switch is opened, the cam assembly releases the driving force on the rotating shaft bracket (31), and the moving contact (32) is separated from the static contact (34).

2. The load switch for the smart meter according to claim 1, characterized in that: The driving mechanism comprises a control board (41) arranged in the housing (1), a motor (42) controlled by the control board (41), a worm (43) and a worm wheel (44) arranged at a driving end of the motor (42), and the worm wheel (44) is engaged with the cam assembly.

3. The load switch for the smart meter according to claim 2, characterized in that: The cam assembly comprises a second rotating shaft (35) arranged in the housing (1), a gear portion (36) arranged on the second rotating shaft (35), and a cam portion (37) arranged on the gear portion (36); the gear portion (36) is engaged with the worm gear (44); when the switch is closed, the cam portion (37) abuts against the rotating shaft bracket (31) and applies a driving force to the rotating shaft bracket (31).

4. The load switch for the smart meter according to claim 1, characterized in that: The rotating shaft bracket (31) comprises a body (311) that rotates around the first rotating shaft (30). The body (311) is provided with a connecting hole (312) and a connecting portion (313). The connecting hole (312) is used to be connected to the reset member (33). The connecting portion (313) abuts against the cam assembly and bears the driving force from the cam assembly.

5. The load switch for the smart meter according to claim 1, characterized in that: There are a plurality of movable contacts (32) and a plurality of stationary contacts (34), and the number of the movable contacts (32) and the stationary contacts (34) are the same and correspond one to one.

6. The load switch for the smart meter according to claim 1, characterized in that: An energy storage component is provided between the moving contact (32) and the rotating shaft bracket (31).

7. The load switch for a smart meter according to claim 1, characterized in that: The isolation mechanism comprises a zero-sequence current transformer (51) arranged on the housing (1) and an isolation bracket (52) arranged in the middle of the zero-sequence current transformer (51); the zero-line assembly comprises a third connecting plate (61); the second connecting plate (22) and the third connecting plate (61) both pass through the zero-sequence current transformer (51); and the isolation bracket (52) isolates the second connecting plate (22) from the third connecting plate (61).

8. The load switch for the smart meter according to claim 7, characterized in that: The isolation bracket (52) is provided with a first through hole (53), and a second through hole (54) and a third through hole (55) are respectively provided on both sides of the first through hole (53); the second connecting plate (22) passes through the second through hole (54), and the third connecting plate (61) passes through the third through hole (55).

9. The load switch for the smart meter according to claim 8, characterized in that: The first end of the isolation bracket (52) is provided with a blocking portion (57) extending in a direction away from the first through hole (53), and the blocking portion (57) limits the first end from passing through the zero-sequence current transformer (51); the second end of the isolation bracket (52) is provided with at least a first limiting portion (58), and the second connecting plate (22) and / or the third connecting plate (61) are provided with a second limiting portion (23), and the first limiting portion (58) corresponds to the second limiting portion (23) one by one.

10. The load switch for a smart electric meter according to claim 1, characterized in that: An arc extinguishing mechanism (7) is provided at the position where the moving contact (32) abuts the static contact (34).

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