A low-voltage single-phase circuit breaker

Abstract

This application relates to a low-voltage single-phase circuit breaker, belonging to the field of power equipment technology. It includes an insulating support, which is equipped with a vacuum protection device for overload protection, a fuse protection device for short-circuit protection, a switching device for connecting and disconnecting the circuit, and a thermistor for overheat protection. The thermistor includes components such as a shape memory alloy, a trigger plate, and a wedge block. The fuse protection device includes contacts, and the switching device includes a permanent magnet assembly, a double rocker assembly, and an auxiliary switch. The shape memory alloy, when heated, triggers a series of actions to achieve circuit disconnection. This application achieves overload, short-circuit, and overheat protection for low-voltage single-phase circuits, with each protection device cooperating to promptly and effectively disconnect the circuit under different fault conditions, ensuring the safe and stable operation of the circuit.

Description

Technical Field

[0001] This application relates to the field of power equipment technology, and in particular to a low-voltage single-phase circuit breaker. Background Technology

[0002] In power systems, low-voltage single-phase circuit breakers are crucial equipment for ensuring the safe operation of circuits. With the continuous growth of electricity demand and the increasing diversification of electrical equipment, higher requirements are placed on the performance and reliability of low-voltage single-phase circuit breakers. Widely used in electrical systems across various sectors, including homes, businesses, and industries, the stable and reliable operation of low-voltage single-phase circuit breakers is essential for ensuring the normal operation of electrical equipment and the safety of personnel. They can promptly disconnect the circuit in case of abnormal conditions, preventing electrical accidents and providing vital protection for the stable operation of the power system.

[0003] In related technologies, circuit protection typically employs a single protection device or a limited combination of several protection methods. For example, some circuit breakers rely solely on fuses for short-circuit protection; when a short circuit occurs, the fuse melts to disconnect the circuit. For overload protection, some use thermal trip units, utilizing the heat generated by current flowing through a heating element to deform a bimetallic strip, thereby triggering the tripping mechanism to disconnect the circuit. Regarding opening and closing control, traditional circuit breakers often use electromagnetic or electric operating mechanisms to connect and disconnect the circuit. These conventional methods can meet basic circuit protection requirements to a certain extent, but they have limitations in practical applications.

[0004] However, because different protection devices operate independently and lack an effective coordination mechanism, it is difficult to achieve comprehensive and timely protection when multiple fault conditions occur in the circuit. For example, a single fuse can only respond to short-circuit faults and cannot provide effective protection against faults such as overload and overheating; while thermal trip units have some function in overload protection, their response speed to short-circuit faults is slow. This limitation of protection function makes traditional low-voltage single-phase circuit breakers unable to provide reliable protection when faced with complex circuit faults, which can easily lead to damage to electrical equipment or even safety accidents. Summary of the Invention

[0005] The purpose of this application is to overcome the above-mentioned technical problems and provide a low-voltage single-phase circuit breaker.

[0006] A low-voltage single-phase circuit breaker includes an insulating support, which is equipped with a vacuum protection device for overload protection, a fuse protection device for short-circuit protection, a switching device for connecting and disconnecting the circuit, and a thermistor for overheat protection. The thermal device includes: A shape memory alloy is used in the opening and closing device. The shape memory alloy has soft metal sheets, which are used to connect the circuit. A trigger plate is mounted on an insulating support. The trigger plate abuts against a shape memory alloy, and the shape memory alloy controls the sliding of the trigger plate on the insulating support. A wedge block is mounted on an insulating bracket. The wedge block is engaged with a trigger plate. A trigger spring is connected to the wedge block, and the trigger spring abuts against the insulating bracket. The fusible link device includes contacts, which are slidably mounted on an insulating support. A connector is threaded through the shape memory alloy and soft metal sheet, and the connector abuts against the contact. When the shape memory alloy is heated, it triggers a spring to start, which in turn drives a wedge block to disconnect the connector from the contact.

[0007] By adopting the above technical solutions, an overload protection device can be set up to achieve overload protection, a short circuit protection device can be set up to achieve short circuit protection, a circuit breaker can be set up to connect and disconnect the circuit, and a thermal device can achieve overheat protection; a soft metal sheet can be set up with shape memory alloy to connect the circuit; the shape memory alloy controls the trigger plate to slide on the insulating support, and the trigger plate is engaged with the wedge block. When the shape memory alloy is heated, the trigger spring is activated, driving the wedge block to disconnect the connector from the contact, which can disconnect the circuit in time when overheating, ensuring circuit safety.

[0008] Preferably, the closing and opening device includes a permanent magnet assembly, a dual rocker assembly, and an auxiliary switch; the permanent magnet assembly includes a closing and opening rod, which is connected to the dual rocker assembly, and the dual rocker assembly is connected to an insulator; the auxiliary switch is used to drive the closing and opening rod to slide, and the dual rocker assembly controls the connection or disconnection of the insulator with the vacuum protection circuit breaker; a soft metal sheet and a shape memory alloy are connected to the insulator.

[0009] By adopting the above technical solution, the opening and closing device is equipped with a permanent magnet component, a double rocker assembly, and an auxiliary switch. The opening and closing rods of the permanent magnet component are connected to the double rocker assembly, which is connected to the insulator. The auxiliary switch drives the opening and closing rods to slide, and the double rocker assembly controls the connection or disconnection of the insulator with the vacuum protection circuit breaker. In addition, the soft metal sheet and shape memory alloy are connected to the insulator, which can realize the connection and disconnection functions of the circuit. At the same time, the thermal device is associated with the opening and closing device to better realize overheat protection.

[0010] Preferably, the insulating bracket has a drive groove, the trigger plate slides in the drive groove, and a pressure sensor is provided at the bottom of the drive groove. The pressure sensor is electrically connected to the auxiliary switch. When the shape memory alloy is heated, it drives the trigger plate to contact the pressure sensor, and the pressure sensor drives the auxiliary switch to run.

[0011] By adopting the above technical solution, a drive groove is opened in the insulating bracket, allowing the trigger plate to slide in the drive groove. A pressure sensor electrically connected to the auxiliary switch is set at the bottom of the drive groove. When the shape memory alloy is heated, it drives the trigger plate to contact the pressure sensor, which can drive the auxiliary switch to run. This realizes automatic control of the auxiliary switch during overheat protection, further ensuring circuit safety.

[0012] Preferably, the wedge plate has a slot, and the trigger plate has a block that extends into the slot. When the shape memory alloy is heated, it drives the block to extend out of the slot.

[0013] By adopting the above technical solution, the low-voltage single-phase circuit breaker has overload, short circuit, overheat protection and circuit connection disconnection functions. The shape memory alloy in the thermal device can control the sliding of the trigger plate when heated; the wedge plate has a slot, and the trigger plate has a block that extends into the slot. When the shape memory alloy is heated, it drives the block to extend out of the slot, which can activate the trigger spring and drive the wedge block to disconnect the connector from the contact, thus realizing the circuit disconnection during overheat protection.

[0014] Preferably, the insulating bracket is provided with an inclined block, the inclined block is provided with a first strip block, and the wedge plate is provided with a second strip block. The trigger spring drives the first strip block to slide along the inclined block and engage with the second strip block, and the wedge block pushes the contact to slide away from the connector.

[0015] By adopting the above technical solution, the insulating bracket is equipped with an inclined block and a first strip block, and the wedge plate is equipped with a second strip block. The trigger spring drives the first strip block to slide along the inclined block and engage with the second strip block, which can increase the distance between the connector and the contact, while preventing the contact from slipping due to the slippage of the wedge block. The wedge block pushes the contact to slide away from the connector, which can realize the reliable disconnection of the connector and the contact. Combined with the overall low-voltage single-phase circuit breaker structure, it can realize multiple protection functions such as overload, short circuit, and overheating.

[0016] Preferably, the dual rocker assembly includes a support frame, with short connecting plates rotatably mounted on both sides of the support frame. The ends of the two short connecting plates are rotatably connected by a connecting rod. A long connecting plate is rotatably mounted on the side of the short connecting rod, and the end of the long connecting plate is rotatably connected to an insulator.

[0017] By adopting the above technical solution, the opening and closing device of the low-voltage single-phase circuit breaker can drive the double rocker assembly to operate through the opening and closing rod of the permanent magnet component. The short connecting plates on both sides of the support frame of the double rocker assembly are connected by connecting rods, and the long connecting plate on the side of the short connecting rod is rotatably connected to the insulator, thereby realizing the connection or disconnection of the control insulator and the vacuum protection circuit breaker, and thus realizing the connection and disconnection of the circuit. It can also be used in conjunction with the shape memory alloy and soft metal sheet of the thermal device to realize the opening and closing control during circuit overheat protection.

[0018] Preferably, the vacuum protection device includes a vacuum arc extinguisher, which has a plug-in hole, into which an insulator is inserted.

[0019] By adopting the above technical solution, overload protection can be achieved by setting up a vacuum arc extinguisher. The insulator is inserted into the plug hole of the vacuum arc extinguisher, which can realize the connection between the insulator and the vacuum arc extinguisher, so that the circuit breaker has the function of overload protection.

[0020] Preferably, the connector is provided with a plug, which is inserted into the nozzle. The nozzle is connected to a gas tank through a pipe, and the gas tank is filled with inert gas. A rubber ring is provided at the connection between the nozzle and the plug, and the rubber ring abuts against the surface of the plug.

[0021] By adopting the above technical solution, the shape memory alloy triggers the spring to start when heated, which can drive the wedge block to disconnect the connector from the contact, thus achieving overheat protection; the connector is equipped with a plug inserted into the nozzle, and the nozzle is connected to a gas cylinder for injecting inert gas. When the temperature in the control chamber rises, the shape memory alloy deforms, causing the plug to be pulled out of the nozzle, and the inert gas can be sprayed out; the rubber ring abuts against the surface of the plug, which can initially fix the position of the connecting plate and the connector, avoiding poor contact between the connector and the contact.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The insulating support is equipped with vacuum protection device, fuse protection device, opening and closing device and thermal device to realize overload, short circuit, overheat protection and circuit connection disconnection, which solves the problem of the single protection function of traditional circuit breaker and can provide comprehensive protection for a variety of faults; 2. When the shape memory alloy is heated, it triggers the spring to start, which drives the wedge block to disconnect the connector from the contact, thus cutting off the circuit in time when overheating, avoiding damage to electrical equipment and safety accidents; 3. The shape memory alloy trigger plate is driven by heat to contact the pressure sensor, and the pressure sensor drives the auxiliary switch to operate, realizing automatic control of opening and closing of the circuit when overheating, thus improving the timeliness and reliability of circuit protection.

[0023] 4. Optimize the internal structure layout of low-voltage circuit breakers to make them more compact and smaller, facilitating installation and maintenance and reducing production costs; 5. Through advanced control technology and intelligent controllers, this invention enables precise control of opening and closing times. When a short circuit or other fault occurs in the power system, the combination of rapid disconnection within 10ms and relay response within 20ms, working in synergy, helps to achieve better coordination between different protection devices. This design has many advantages and unique operating logic in power protection systems. During normal operation, the current is at a relatively low level and below 40kA, allowing the circuit breaker to stably carry and control the current flow, ensuring normal power supply to the power lines. The circuit breaker possesses multiple protection functions and intelligent control capabilities, enabling it to monitor and respond to abnormal conditions such as overload and undervoltage in the lines, thus maintaining the stable operation of the power system to a certain extent. When a fault occurs and the current exceeds 40kA or reaches a high current state, the fuse activates to block the circuit. The fuse has a fast response and strong current breaking capacity; its fusible element melts rapidly when a large current passes through, forming a reliable circuit. Under high current conditions, the severity and urgency of faults necessitate extremely rapid disconnection. Fuses can interrupt current in a very short time, preventing catastrophic damage to the entire power system caused by excessive current, such as avoiding conductor overheating and fires, or severe equipment damage, thereby ensuring the safety of the power system. Furthermore, this collaborative operation of circuit breakers and fuses achieves graded protection. Circuit breakers leverage their advantages of precise control and repeatable operation under normal and moderate fault current conditions, while fuses provide ultimate, one-time, rapid protection under extreme high current conditions. The two complement each other, improving the reliability, flexibility, and comprehensiveness of power system protection, contributing to optimized power system design and operation, reducing overall protection costs, and extending equipment lifespan. 6. Independent unidirectional modules, freely combinable. Each independent unidirectional module is equipped with standardized interfaces, including input and output interfaces. These interfaces adopt unified specifications and connection methods to ensure quick and reliable connection without complex debugging; 7. Replacing fuses is quick and easy, featuring a convenient plug-in design that significantly shortens replacement time, improves operational safety, reduces maintenance costs, and enables rapid power restoration. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a schematic diagram of the overall structure of this application, showing the main transmission lead screw; Figure 3 This is a structural schematic diagram of the present application, mainly illustrating the auxiliary switch; Figure 4 This is a structural schematic diagram of the present application, mainly showing the closing and opening gate arm; Figure 5This is a structural schematic diagram of the present application, mainly showing the short connecting plate, the long connecting plate, and the support frame; Figure 6 This is a cross-sectional structural diagram of the present application, mainly showing the connector and contact; Figure 7 This is a structural schematic diagram of the present application, mainly showing the mounting plate; Figure 8 This is a cross-sectional structural diagram of this application, mainly showing the nozzle.

[0025] Figure Descriptions: 1. Insulating bracket; 2. Mounting column; 3. Drawer panel; 4. Fuse unit nameplate; 5. Factory serial number nameplate; 6. Close / open indicator; 7. Close / open button assembly; 8. Operating procedure; 9. Handle; 10. Guide bar; 11. Guide groove; 12. Grounding copper sheet; 13. Baffle; 14. Rotating hole; 15. Dust cover; 16. Drive screw; 17. Threaded groove; 18. First washer; 19. Screw spring; 20. Support plate; 21. Secondary plug-in; 22. Guide rod; 23. Switch cavity; 24. Mounting cavity; 25. Control cavity; 26. Drive cavity; 27. Auxiliary switch; 28. Connecting plate; 29. ​​Permanent magnet assembly; 30. Close / open lever; 31. Debugging buffer; 32. Support frame; 33. Short connecting plate; 34. Connecting rod; 35. Long connecting plate; 36. Fixing rod; 37. Positioning groove; 8. Positioning plate; 39. Positioning hole; 40. Insulator; 41. Connector; 42. Vacuum interrupter; 43. Output terminal; 44. Fixing post; 45. Fuse; 46. Connecting copper plate; 47. Input terminal; 48. Flexible connector; 49. Contact; 50. Adapter post; 51. Adapter groove; 52. Shape memory alloy; 53. Flexible metal sheet; 54. Clamping plate; 55. Second gasket; 56. Connection 57. Head; 58. Drive slot; 59. Pressure sensor; 60. Trigger plate; 61. Pressure plate; 62. Limit slot; 63. Wedge block; 64. Arc groove; 65. Snap-fit ​​hole; 66. Snap-fit ​​groove; 67. Trigger spring; 68. Inclined block; 69. Strip block; 70. Strip groove; 71. Mounting plate; 72. Air tank; 73. Nozzle; 74. Rubber ring; 75. Connecting plate; 76. Plug. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1 - Appendix Figure 8 This application will be described in further detail below.

[0027] A low-voltage single-phase circuit breaker, referenced Figure 1 It includes an insulating support 1, which is equipped with a vacuum protection device for overload protection, a fuse protection device for short circuit protection, a switching device for connecting and disconnecting circuits, and a thermistor for overheat protection.

[0028] Reference Figure 1 , Figure 2 A plurality of mounting posts 2 are fixedly connected to one side of the insulating bracket 1, and a drawer panel 3 is fixedly connected to the end of the mounting posts 2. A fuse unit nameplate 4 is fixedly connected to the upper surface of the drawer panel 3, and a factory code nameplate 5 is fixedly connected to one side of the fuse unit nameplate 4. At the same time, a closing / opening indicator 6 is fixedly connected to the lower surface of the drawer panel 3, and a closing / opening button assembly 7 is fixedly connected to the drawer panel 3 below the closing / opening indicator 6. An operating procedure 8 is fixedly connected between the closing / opening indicator 6 and the closing / opening button assembly 7. A handle 9 for pulling the panel and the insulating bracket 1 is fixedly connected to one side of the operating procedure 8.

[0029] Guide strips 10 are fixedly connected to both sides of the bottom surface of the insulating bracket 1 by screws. Guide grooves 11 are formed on the guide strips 10 for sliding connection with the external mounting box, and the openings of the two guide grooves 11 are located on opposite sides of the two guide strips 10. Additionally, a grounding copper plate 12 is fixedly connected to the bottom surface of the insulating bracket 1. Two alternately arranged baffles 13 are fixedly connected between the two guide strips 10 on the bottom surface of the insulating bracket 1, and the arrangement direction of the two baffles 13 is the same as the sliding direction of the insulating bracket 1. A rotating hole 14 is formed in the drawer panel 3, and a dust cover 15 for closing or opening the rotating hole 14 is fixedly connected to the drawer panel 3 at the rotating hole 14. Simultaneously, a transmission screw 16 is rotatably connected to the drawer panel 3 at the rotating hole 14.

[0030] Two baffles 13 are sequentially inserted through one end of the transmission screw 16, and a threaded groove 17 is provided on the surface between the end of the transmission screw 16 and the baffle 13 closest to its own end. In use, the transmission screw 16 can be threadedly connected to an external mounting box through the threaded groove 17, and the insulating bracket 1 can be opened or closed by rotating the transmission screw with a tool. In addition, several first washers 18 are axially fitted on the upper surface of the transmission screw 16, and the side of the first washer 18 abuts against the corresponding baffle 13. At the same time, a screw spring 19 is axially fitted on the surface of the transmission screw 16 between two baffles 13, and the two ends of the screw spring 19 abut against the first washer 18 at the corresponding positions. At the same time, a shaft pin is inserted through the transmission screw 16, and the shaft pin abuts against the first washer 18 on the baffle 13 near the drawer panel 3.

[0031] Reference Figure 1 The top surface of the insulating bracket 1 is fixedly connected to a support plate 20 by a nut. The surface of the support plate 20 is fixedly connected to a secondary plug 21. The two sides of the secondary plug 21 are fixedly connected to guide rods 22 by screws. In use, the guide rods 22 extend into the corresponding slots on the external mounting box, and the secondary plug 21 is inserted into the corresponding snap-fit ​​slots on the external mounting box.

[0032] Reference Figure 1 , Figure 2 , Figure 3 An insulating bracket 1 has a first partition, a second partition, and a third partition fixedly connected inside. These partitions work together to divide the interior of the insulating bracket 1 into a switching cavity 23, a mounting cavity 24, a control cavity 25, and a drive cavity 26. The closing / opening device includes an auxiliary switch 27 fixedly connected within the switching cavity 23. The auxiliary switch 27 is connected to a contact plate 28 via a pin. Simultaneously, a permanent magnet assembly 29 is fixedly connected within the drive cavity 26. The contact plate 28 passes through the first partition and is fixedly connected to the permanent magnet assembly 29, thereby enabling the auxiliary switch 27 to provide power to the permanent magnet assembly 29.

[0033] Reference Figure 4 , Figure 5 The permanent magnet assembly 29 includes a closing / opening lever 30, which extends through a second partition into the control cavity 25. A buffer element 31 is axially fitted onto the closing / opening lever 30 within the control cavity 25 to reduce wear during operation. A double rocker assembly is connected to the end of the closing / opening lever 30. The double rocker assembly includes a support frame 32 fixedly connected to the insulating bracket 1. The support frame 32 has a "T"-shaped cross-section, and a pin is inserted into the end of the support frame 32. Short connecting plates 33 are rotatably connected to both ends of the pin, with the two short connecting plates 33 located on opposite sides of the support frame 32. A connecting rod 34 is rotatably connected to the end of each short connecting plate 33 away from the support frame 32 via a pin, and the connecting rod 34 is located between the two short connecting plates 33. The end of the connecting rod 34 is connected to the closing / opening lever 30 via a pin. Two long connecting plates 35 are rotatably connected to the pin connecting the connecting rod 34 and the short connecting plate 33, and the long connecting plates 35 are located between the connecting rod 34 and the short connecting plate 33. At the same time, two fixing rods 36 are fixedly connected between the two long connecting plates 35, and the fixing rods 36 are used to increase the rigidity between the two long connecting plates 35.

[0034] Reference Figure 2 , Figure 4 , Figure 5 The insulating support 1 has a positioning groove 37 on the side wall inside the control cavity 25. A positioning plate 38 is slidably connected in the positioning groove 37, and the positioning plate 38 is fixed to the bottom surface of the insulating support 1 by bolts. Additionally, a positioning hole 39 is provided in the positioning plate 38, and an insulator 40 passes through the positioning hole 39 and slides within it. One end of the insulator 40 is rotatably connected to the end of the long connecting plate 35 away from the connecting rod 34 via a pin, and the other end of the insulator 40 is fixedly connected to a connector 41. Furthermore, the vacuum protection device includes a vacuum arc extinguisher 42 fixedly connected in the control cavity 25. An output head 43 is fixedly connected to the end of the vacuum arc extinguisher 42 away from the insulator 40, and a plug hole is provided at the end of the vacuum arc extinguisher 42 near the insulator 40. The connector 41 on the insulator 40 can extend into the plug hole, thereby achieving docking between the insulator 40 and the vacuum arc extinguisher 42.

[0035] Reference Figure 4 , Figure 6 The insulating bracket 1 has two fixed posts 44 fixedly connected within the mounting cavity 24. The fusible protection device includes a fuse 45 fixedly connected to the fixed posts 44 by screws, and the fuse 45 is located between the two fixed posts 44. A connecting copper plate 46 is fixedly connected to the fixed post 44 located away from the permanent magnet assembly 29. At the same time, one end of the connecting copper plate 46 is fixedly connected to an inlet head 47 by screws. Furthermore, a contact 49 is fixedly connected to the side of the fuse 45 away from the connecting copper plate 46 by a flexible connector 48. Meanwhile, the insulating bracket 1 has a transition post 50 fixedly connected within the mounting cavity 24. The transition post 50 has a transition groove 51, and the mounting cavity 24 and the control cavity 25 are connected through the transition groove 51. The contact 49 extends into the transition groove 51 and slides along the inner wall of the transition groove 51.

[0036] Reference Figure 4 , Figure 5 , Figure 6 The thermal device includes a shape memory alloy 52 sleeved on a connector 41 and a flexible metal sheet 53 fixedly connected to the surface of the shape memory alloy 52. ​​A clamping plate 54 is sleeved on one side of the flexible metal sheet 53, and a second gasket 55 is sleeved on the other side of the shape memory alloy 52, thereby mounting the shape memory alloy 52 and the flexible metal sheet 53 onto the connector 41. Furthermore, connectors 56 pass through the ends of the shape memory alloy 52 and the flexible metal sheet 53, extending into the adapter groove 51 and abutting against the contact 49, thereby connecting the circuit between the input head 47 and the output head 43. Additionally, the shape memory alloy 52 has a double-stroke design; when heated, it causes the flexible metal sheet 53 to bend, disengaging the connector 56 from the contact 49. When the temperature decreases, it causes the flexible metal sheet 53 to return to its original shape.

[0037] Reference Figure 3 , Figure 6 The positioning plate 38 has a drive groove 57, and a pressure sensor 58 is fixedly connected to the bottom of the drive groove 57. The pressure sensor 58 is electrically connected to the auxiliary switch 27. A rubber trigger plate 59 is slidably connected inside the drive groove 57, and the trigger plate 59 abuts against the inner wall of the drive groove 57. A pressure plate 60 is fixedly connected to one side of the trigger plate 59, and the pressure plate 60 is located below the shape memory alloy 52. ​​This allows the shape memory alloy 52 to deform under heat, pushing the trigger plate 59 towards the pressure sensor 58, thereby triggering the auxiliary switch 27. Reference Figure 6The insulating bracket 1 has a limiting groove 61 in the mounting cavity 24. Simultaneously, the side wall of the adapter post 50 has a through groove, allowing the adapter groove 51 to communicate with the limiting groove 61. An insulating ceramic wedge block 62 is slidably connected within the limiting groove 61. The wedge block 62 has an opening and extends into the adapter groove 51. The smaller end of the wedge block 62 faces towards the contact 49 and connector 56. Both the contact 49 and connector 56 have arc-shaped grooves 63 on their sides. Furthermore, the bottom of the limiting groove 61 has a locking hole 64, and the bottom surface of the wedge block 62 has a locking groove 65. A locking block 66, passing through the locking hole 64 and extending into the locking groove 65, is fixedly connected to the trigger plate 59. A trigger spring 67 is fixedly connected to the side wall of the limiting groove 61 away from the adapter post 50. The end of the trigger spring 67 is fixedly connected to the surface of the wedge block 62. When the locking block 66 extends into the locking groove 65, the trigger spring 67 is in a compressed state. When the locking block 66 disengages from the locking groove 65, the small end of the wedge block 62 abuts against the inner wall of the arc groove 63 on the contact 49 and the connector 56, thereby separating the contact 49 from the connector 56.

[0038] An inclined block 68 is fixedly connected to the insulating bracket 1 within the mounting cavity 24. The inclined block 68 is located between the adapter post 50 and the fixed post 44, and the inclined surface of the inclined block 68 faces towards the wedge block 62. In addition, a strip block 69 is fixedly connected to the inclined surface of the inclined block 68, and a strip groove 70 is formed on the bottom surface of the wedge block 62. The trigger spring 67 pushes the wedge block 62 to slide along the inclined surface of the inclined block 68, so that the strip groove 70 aligns with the strip block 69, thereby increasing the distance between the connector 56 and the contact 49, and preventing the contact 49 from slipping due to the slippage of the wedge block 62.

[0039] Reference Figure 6 , Figure 7 , Figure 8 An insulating bracket 1 is fixedly connected to a ring-shaped mounting plate 71 on the top surface of the control cavity 25, and the mounting plate 71 has a cavity. Additionally, an air tank 72 is fixedly connected to the insulating bracket 1 within the control cavity 25. The air tank 72 is filled with compressed inert gas, and it communicates with the cavity in the mounting plate 71 via a pipe. Nozzles 73 are fixedly connected to both sides of the connector 56 on the mounting plate 71. Rubber rings 74 are fixedly connected to the inner walls of the nozzles 73. A connecting plate 75 is fixedly connected to the connector 56, and a plug 76 is fixedly connected to the connecting plate 75, inserting into the nozzle 73. When the temperature inside the control cavity 25 rises and the shape memory alloy 52 deforms, the shape memory alloy 52 drives the plug 76 to be pulled out of the nozzle 73, thereby causing the inert gas in the air tank 72 to be ejected from the nozzle 73. In addition, the rubber ring 74 abuts against the surface of the plug 76, thereby initially fixing the position of the connecting plate 75 and the connector 56 to avoid poor contact between the connector 56 and the contact 49 during use.

[0040] The implementation principle of this application embodiment is as follows: Under normal conditions, the soft metal sheet 53 abuts against the contact 49 through the connector 56, and the circuit is connected; the opening and closing device drives the opening and closing rod 30 through the auxiliary switch 27, which drives the double rocker assembly (including support frame 32, short connecting plate 33, connecting rod 34 and long connecting plate 35) to move, so that the insulator 40 is inserted into the insertion hole of the vacuum arc extinguisher 42, and the circuit is kept running stably.

[0041] When a circuit fault occurs, the temperature inside the control cavity 25 rises, causing the shape memory alloy 52 to deform due to heat, which in turn causes the soft metal sheet 53 to bend. The shape memory alloy 52 pushes the trigger plate 59 to slide within the drive groove 57, and the locking block 66 on the trigger plate 59 disengages from the locking groove 65 of the wedge block 62. The trigger spring 67 is released, driving the wedge block 62 to slide along the inclined block 68; the first strip block 69 engages with the second strip block 69, and the wedge block 62 pushes the contact 49 to slide away from the connector 56, causing the connector 56 to disconnect from the contact 49 and cutting off the circuit.

[0042] At the same time, the trigger plate 59 comes into contact with the pressure sensor 58 at the bottom of the drive slot 57. The signal from the pressure sensor 58 drives the auxiliary switch 27 to operate, which in turn drives the opening and closing device to move (the opening and closing lever 30 slides and the double rocker assembly is linked), causing the insulator 40 to separate from the vacuum arc extinguisher 42 and the strengthening circuit to break.

[0043] The deformation of the shape memory alloy 52 also causes the plug 76 to be pulled out of the nozzle 73, and the inert gas in the gas tank 72 is ejected through the nozzle 73 to suppress the electric arc and improve safety.

[0044] In addition, the overload current causes the vacuum arc extinguisher 42 to activate, and the insulator 40 automatically separates from the plug hole through the double rocker assembly, thereby extinguishing the arc and disconnecting the circuit.

[0045] If an overload is accompanied by a temperature rise, the deformation of the shape memory alloy 52 accelerates the aforementioned overheat protection process. The short-circuit current causes the fuse 45 to melt, and the contact 49 slides within the transition groove 51, disengaging from the connector 56 and directly breaking the circuit. The wedge block 62, under the action of the trigger spring 67, keeps the contact 49 separated from the connector 56 to prevent accidental connection.

[0046] Meanwhile, upon triggering overheating or a short circuit, the pressure sensor 58 ensures synchronized operation of the opening and closing devices via the auxiliary switch 27, achieving a multiple disconnection mechanism; the inert gas system enhances the arc-extinguishing effect in case of overheating. Ultimately, this circuit breaker can promptly and reliably disconnect the circuit under faults such as overload, short circuit, and overheating, ensuring the safe and stable operation of low-voltage single-phase circuits.

[0047] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low-voltage single-phase circuit breaker, characterized in that: Includes an insulating support (1), which is provided with a vacuum protection device for overload protection, a fuse protection device for short circuit protection, a circuit breaker for connecting and disconnecting circuits, and a thermistor for overheat protection. The thermal device includes: A shape memory alloy (52) is disposed on the opening and closing device. The shape memory alloy (52) is provided with a soft metal sheet (53), which is used to connect the circuit. A trigger plate (59) is disposed on an insulating bracket (1). The trigger plate (59) abuts against a shape memory alloy (52). The shape memory alloy (52) controls the trigger plate (59) to slide on the insulating bracket (1). A wedge block (62) is set on an insulating bracket (1). The wedge block (62) is engaged with a trigger plate (59). A trigger spring (67) is connected to the wedge block (62). The trigger spring (67) abuts against the insulating bracket (1). The fuse protection device includes a contact (49), which is slidably disposed with respect to the insulating support (1); A connector (56) is provided on the shape memory alloy (52) and the soft metal sheet (53), and the connector (56) abuts against the contact (49); When the shape memory alloy (52) is heated, the trigger spring (67) is activated, and the trigger spring (67) drives the wedge block (62) to disconnect the connector (56) from the contact (49).

2. A low-voltage single-phase circuit breaker according to claim 1, characterized in that: The opening and closing device includes a permanent magnet assembly (29), a dual rocker assembly, and an auxiliary switch (27); The permanent magnet assembly (29) includes a closing / opening gate arm (30), which is connected to a double rocker assembly, and the double rocker assembly is connected to an insulator (40). The auxiliary switch (27) is used to drive the closing and opening lever (30) to slide, and the double rocker assembly controls the connection or disconnection of the insulator (40) with the vacuum protection circuit breaker; The soft metal sheet (53) and shape memory alloy (52) are connected to the insulator (40).

3. A low-voltage single-phase circuit breaker according to claim 2, characterized in that: The insulating bracket (1) has a drive groove (57), the trigger plate (59) slides in the drive groove (57), and a pressure sensor (58) is provided at the bottom of the drive groove (57). The pressure sensor (58) is electrically connected to the auxiliary switch (27). When the shape memory alloy (52) is heated, it drives the trigger plate (59) to contact the pressure sensor (58), and the pressure sensor (58) drives the auxiliary switch (27) to run.

4. A low-voltage single-phase circuit breaker according to claim 1, characterized in that: The wedge block (62) has a slot (65), and the trigger plate (59) is provided with a block (66) that extends into the slot (65). When the shape memory alloy (52) is heated, it drives the block (66) to extend out of the slot (65).

5. A low-voltage single-phase circuit breaker according to claim 4, characterized in that: The insulating bracket (1) is provided with a ramp block (68), the ramp block (68) is provided with a first strip block, the wedge block (62) is provided with a second strip block, the trigger spring (67) drives the first strip block to slide along the ramp block (68) and engage with the second strip block, and the wedge block (62) pushes the contact (49) to slide away from the connector (56).

6. A low-voltage single-phase circuit breaker according to claim 2, characterized in that: The dual rocker assembly includes a support frame (32), on both sides of the support frame (32) are rotatably provided with short connecting plates (33), the ends of the two short connecting plates (33) are rotatably connected by a connecting rod (34), and a long connecting plate (35) is rotatably provided on the side of the connecting rod (34), the end of the long connecting plate (35) is rotatably connected to an insulator (40).

7. A low-voltage single-phase circuit breaker according to claim 6, characterized in that: The vacuum protection device includes a vacuum arc extinguisher (42), which has a plug hole, and the insulator (40) is inserted into the plug hole.

8. A low-voltage single-phase circuit breaker according to claim 1, characterized in that: The connector (56) is provided with a plug (76), the plug (76) is inserted into the nozzle (73), the nozzle (73) is connected to a gas tank (72) through a pipe, and the gas tank (72) is filled with inert gas; A rubber ring (74) is provided at the connection between the nozzle (73) and the plug (76), and the rubber ring (74) abuts against the surface of the plug (76).

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