A plastic molded case circuit breaker
By employing a dual protection structure of arc-extinguishing grids and arc-blocking covers in the molded case circuit breaker, along with a heat-conducting and heat-dissipating design, and combined with high-temperature resistant polyimide coating, the risks of arc reignition and breakdown are resolved, achieving efficient arc extinguishing and improved insulation performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGSHU TONGRUN SWITCHGEAR FACTORY CO LTD
- Filing Date
- 2025-08-27
- Publication Date
- 2026-07-31
AI Technical Summary
Traditional molded case circuit breakers have a simple arc-extinguishing grid layout, resulting in low arc-splitting efficiency, which can easily lead to arc reignition and breakdown risks. Furthermore, high temperatures tend to accumulate during high-current interruption, reducing insulation performance.
It adopts a dual protection structure of arc-extinguishing grid and arc-blocking cover, and works in conjunction with heat conduction plate and heat sink for heat dissipation. It is also coated with high-temperature resistant polyimide arc-extinguishing coating to enhance insulation performance.
It improves arc breaking capability, reduces the risk of arc reignition and breakdown, extends service life, effectively controls temperature rise, and enhances insulation performance.
Smart Images
Figure CN224582240U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit breaker technology, specifically to a molded case circuit breaker that is resistant to breakdown. Background Technology
[0002] Molded case circuit breakers are devices used for long-delay overload and instantaneous short-circuit protection. They include characteristics such as rated ultimate short-circuit breaking capacity and current-limiting breaking capacity. Molded case circuit breakers are key devices in power systems for overload and short-circuit protection. Their core function is to quickly interrupt fault current and effectively extinguish arcs to prevent arc breakdown or fire. Traditional molded case circuit breakers suffer from problems such as a simple arc-extinguishing grid layout and low arc-splitting efficiency, which can easily lead to arc reignition or residual high-temperature ions, increasing the risk of breakdown. At the same time, the high temperature generated during high-current interruption tends to accumulate inside the case, accelerating plastic aging and reducing insulation performance. Therefore, we propose a breakdown-proof molded case circuit breaker. Utility Model Content
[0003] The technical problem to be solved by this utility model is to overcome the existing defects and provide a circuit breaker with protection against breakdown. It adopts a double protection structure of arc-extinguishing grid and arc-blocking cover, which greatly improves the arc-extinguishing efficiency and reduces the risk of breakdown. It is equipped with heat-conducting plate and heat sink for heat dissipation, which effectively controls the temperature rise and extends the service life. In addition, it is coated with high-temperature resistant polyimide arc-extinguishing coating to further enhance the insulation performance, which can effectively solve the problems in the background art.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a circuit breaker with protection against breakdown, comprising a casing, an arc-extinguishing unit, and fixing bolts; The housing has a device slot on the top surface, and the fixing bolts are threaded through the through holes on the surface of the housing and the screw holes on the top surface of the housing. The side of the housing is provided with a heat dissipation unit. Arc extinguishing unit: includes an arc extinguishing cover, an arc extinguishing grid, a card holder and a card slot. The card slot is opened inside the device slot. The card holder is fixed on the front side of the arc extinguishing cover. The card holder is inserted into the card slot. Arc extinguishing grids are evenly fixed on the left and right sides inside the arc extinguishing cover. It also includes connecting terminals, which are evenly installed on the front and rear sides of the housing.
[0005] The card holder is inserted into the card slot to install the arc extinguishing cover. Together with the arc extinguishing grid, it can increase the arc segmentation capability, so as to isolate the arc path generated by the contacts inside the device slot, prevent the arc from spreading and reigniting, and thus improve the anti-breakdown effect of the plastic shell.
[0006] Furthermore, the arc-extinguishing unit also includes an arc-isolating cover, heat dissipation holes, a T-shaped block, a partition plate, and a T-shaped groove. The partition plate is installed inside the arc-isolating cover, and the T-shaped block is fixed on the inner side of the partition plate. The T-shaped groove is opened on the top surface of the housing, and the T-shaped block and the T-shaped groove are slidably installed. The surface of the arc-isolating cover is provided with heat dissipation holes. The T-shaped block and the T-shaped groove are slidably installed to install the arc-isolating cover. This can prevent the arc from occurring at the connection terminal, while the heat dissipation holes heat the high-temperature gas for discharge.
[0007] Furthermore, the arc-extinguishing unit also includes a spring groove, a spring, a locking frame, and a locking groove. The spring groove is formed on the left and right sides of the arc-extinguishing cover. The inside of the spring groove is connected to one end of the spring, and the other end of the spring is equipped with a locking frame. The locking groove is formed at the ends of the left and right sides of the housing. When the spring contracts, the locking frame is inserted into the locking groove to install the arc-extinguishing cover. This facilitates disassembly and assembly for subsequent use.
[0008] Furthermore, the heat dissipation unit includes a heat-conducting plate, a heat sink, a mounting bracket, and a placement slot. The placement slot is formed on the inner wall of the device slot, and the heat-conducting plate is snapped into the inside of the placement slot. The end of the heat-conducting plate is attached to the heat sink. The mounting bracket is fixed to the side of the device housing, and the heat sink is installed inside the mounting bracket. Heat is directly absorbed by the heat-conducting plate embedded in the inner wall of the device slot, and the heat is discharged through the heat sink to form an active heat dissipation channel to prevent overheating inside the device housing from reducing the insulation effect.
[0009] Furthermore, it also includes a transparent window, a limiting plate, and a limiting groove. The transparent window is opened on both sides of the top surface of the shell cover. There are two limiting plates, which are fixed to the bottom surface of the shell cover on the left and right sides respectively. There are two limiting grooves, which are opened on the top surface of the shell cover respectively. The limiting plates and limiting grooves are inserted into each other to ensure accurate positioning of the shell cover and avoid poor sealing caused by misalignment.
[0010] Furthermore, it also includes an arc-extinguishing coating, which is uniformly coated on the inner surface of the casing and the cover. The arc-extinguishing coating is a polyimide coating. The use of polyimide in the arc-extinguishing coating can decompose into arc-extinguishing gases such as hydrogen and carbon dioxide at the high temperature of the electric arc, thereby improving the arc-extinguishing effect.
[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This breakdown-resistant molded case circuit breaker has the following advantages: 1. The arc extinguishing cover is installed by inserting it into the slot using a card holder. In conjunction with the arc extinguishing grid, it can increase the arc segmentation capability, thereby isolating the arc path generated by the contacts inside the device slot to prevent arc spread and reignition. The arc extinguishing coating uses polyimide, which can decompose into arc extinguishing gases such as hydrogen and carbon dioxide at high arc temperatures, thereby improving the arc extinguishing effect and thus improving the anti-breakdown effect of the plastic shell.
[0012] 2. Heat is directly absorbed by the heat-conducting plate embedded in the inner wall of the device slot, and the heat is discharged through the heat sink to form an active heat dissipation channel to prevent the inside of the device from overheating and reducing the insulation effect. The limiting plate and the limiting slot are inserted to ensure the accurate positioning of the cover and avoid misalignment that leads to poor sealing. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the arc-extinguishing unit structure of this utility model; Figure 3 This is a schematic diagram of the heat dissipation unit structure of this utility model; Figure 4 This is a schematic diagram of the arc-extinguishing coating structure of this utility model.
[0014] In the diagram: 1. Housing, 2. Arc extinguishing unit, 21. Arc extinguishing cover, 22. Arc extinguishing grid, 23. Card holder, 24. Card slot, 25. Arc isolation cover, 26. Heat dissipation hole, 27. T-block, 28. Partition plate, 29. T-slot, 210. Spring slot, 211. Spring, 212. Locking frame, 213. Locking groove, 3. Heat dissipation unit, 31. Heat conduction plate, 32. Heat sink, 33. Mounting bracket, 34. Placement slot, 4. Electrical component slot, 5. Connecting terminal, 6. Housing cover, 7. Fixing bolt, 8. Transparent window, 9. Limiting plate, 10. Limiting groove, 11. Arc extinguishing coating. Detailed Implementation
[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0016] Please see Figure 1-4 This embodiment provides a technical solution: a circuit breaker with protection against breakdown, comprising a housing 1, an arc extinguishing unit 2, and fixing bolts 7; Container 1: The top surface has a device slot 4. The fixing bolt 7 passes through the through hole on the surface of the cover 6 and is threaded into the screw hole on the top surface of the container 1. The side of the container 1 is provided with a heat dissipation unit 3. The heat dissipation unit 3 includes a heat-conducting plate 31, a heat sink 32, a mounting bracket 33 and a placement slot 34. The placement slot 34 is opened in the inner wall of the device slot 4. The heat-conducting plate 31 is snapped into the inside of the placement slot 34. The end of the heat-conducting plate 31 is attached to the heat sink 32. The mounting bracket 33 is fixed to the side of the container 1. The heat sink 32 is installed inside the mounting bracket 33. The heat is directly absorbed by the heat-conducting plate 31 embedded in the inner wall of the device slot 4 and the heat is discharged by the heat sink 32 to form an active heat dissipation channel to prevent the inside of the container 1 from overheating and reducing the insulation effect. Arc extinguishing unit 2 includes an arc extinguishing cover 21, arc extinguishing grid plates 22, a bracket 23, and a slot 24. The slot 24 is located inside the device slot 4. The bracket 23 is fixed to the front side of the arc extinguishing cover 21, and the bracket 23 is inserted into the slot 24. Arc extinguishing grid plates 22 are evenly fixed to the left and right sides inside the arc extinguishing cover 21. Arc extinguishing unit 2 also includes an arc isolation cover 25, heat dissipation holes 26, T-shaped blocks 27, partitions 28, and T-shaped grooves 29. The partitions 28 are installed inside the arc isolation cover 25, and T-shaped blocks 27 are fixed to the inner side of the partitions 28. The T-shaped grooves 29 are located on the top surface of the housing 1, and the T-shaped blocks 27 and T-shaped grooves 29 are slidably installed. Heat dissipation holes 26 are provided on the surface of the arc isolation cover 25. The arc-extinguishing unit 25 is installed by sliding the T-slot 29 to prevent arcing at the connection terminal 5. The heat dissipation hole 26 is used to heat and discharge high-temperature gas. The arc-extinguishing unit 2 also includes a spring groove 210, a spring 211, a locking frame 212, and a locking groove 213. The spring groove 210 is opened on the left and right sides of the arc-extinguishing cover 25. The inside of the spring groove 210 is connected to one end of the spring 211. The other end of the spring 211 is equipped with the locking frame 212. The locking groove 213 is opened at the ends of the left and right sides of the housing 1. When the spring 211 contracts, the locking frame 212 is inserted into the locking groove 213 to install the arc-extinguishing cover 25. This facilitates disassembly and assembly for subsequent use. The device also includes connecting terminals 5, which are evenly installed on the front and rear sides of the housing 1. A bracket 23 is inserted into a slot 24 to install the arc-extinguishing cover 21. Together with the arc-extinguishing grid 22, it increases the arc-splitting capability, isolating the arc path generated by the contacts inside the device slot 4 to prevent arc propagation and reignition, thereby improving the puncture resistance of the plastic housing. It also includes a transparent window 8, a limiting plate 9, and a limiting groove 10. The transparent window 8 is located on both sides of the top surface of the housing cover 6. There are two limiting plates 9, one on the left and one on the right, fixed to the housing cover. The bottom surface of the cover 6 has two limiting grooves 10, which are respectively opened on the top surface of the housing 1. The limiting plate 9 is inserted into the limiting groove 10. The insertion of the limiting plate 9 into the limiting groove 10 ensures the accurate positioning of the cover 6 and avoids poor sealing caused by misalignment. It also includes an arc extinguishing coating 11, which is evenly coated on the inner surface of the housing 1 and the cover 6. The arc extinguishing coating 11 is a polyimide coating. The arc extinguishing coating 11 uses polyimide, which can decompose into arc extinguishing gases such as hydrogen and carbon dioxide at the high temperature of the electric arc, thereby improving the arc extinguishing effect.
[0017] The working principle of the anti-breakdown molded case circuit breaker provided by this utility model is as follows: First, the bracket 23 is inserted into the slot 24 to install the arc extinguishing cover 21. Together with the arc extinguishing grid 22, it can increase the arc-splitting capability, thus isolating the arc path generated by the contacts inside the device slot 4 to prevent arc propagation and reignition, thereby improving the anti-breakdown effect of the molded case. Simultaneously, the T-block 27 and T-slot 29 are slidably installed to install the arc isolation cover 25, which can prevent arcing at the connection terminal 5. The heat dissipation hole 26 heats the high-temperature gas. When the body is discharged, the spring 211 contracts, causing the locking bracket 212 to be inserted into the locking groove 213 to install the arc-quenching cover 25. This facilitates disassembly and assembly for subsequent use. The heat-conducting plate 31 is embedded in the inner wall of the device groove 4 to directly absorb heat, and the heat is discharged through the heat sink 32 to form an active heat dissipation channel to prevent overheating inside the casing 1 from reducing the insulation effect. The arc-quenching coating 11 on the inner side of the casing 1 and the cover 6 is made of polyimide, which can decompose into arc-quenching gases such as hydrogen and carbon dioxide at the high temperature of the electric arc, thereby improving the arc-quenching effect.
[0018] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.
Claims
1. A line of break plastic molded case circuit breaker characterized by: It includes the housing (1), the arc extinguishing unit (2), and the fixing bolts (7); The housing (1) has a device groove (4) on the top surface. The fixing bolt (7) passes through the through hole on the surface of the cover (6) and is threaded into the screw hole on the top surface of the housing (1). The side of the housing (1) is provided with a heat dissipation unit (3). Arc extinguishing unit (2): includes an arc extinguishing cover (21), an arc extinguishing grid plate (22), a card holder (23) and a card slot (24). The card slot (24) is opened inside the device slot (4). The card holder (23) is fixed on the front side of the arc extinguishing cover (21). The card holder (23) is inserted into the card slot (24) in a corresponding manner. The arc extinguishing grid plates (22) are evenly fixed on the left and right sides inside the arc extinguishing cover (21). It also includes connecting terminals (5), which are evenly installed on the front and rear sides of the housing (1).
2. A plastic molded case circuit breaker that prevents arcing in accordance with claim 1, wherein: The arc extinguishing unit (2) also includes an arc shield (25), heat dissipation holes (26), a T-shaped block (27), a partition plate (28), and a T-shaped groove (29). The partition plate (28) is installed inside the arc shield (25). The T-shaped block (27) is fixed on the inner side of the partition plate (28). The T-shaped groove (29) is opened on the top surface of the shell (1). The T-shaped block (27) and the T-shaped groove (29) are slidably installed. The surface of the arc shield (25) is provided with heat dissipation holes (26).
3. A circuit breaker protected against breakdown according to claim 2, characterized in that: The arc extinguishing unit (2) also includes a spring groove (210), a spring (211), a locking frame (212), and a locking groove (213). The spring groove (210) is opened on the left and right sides of the arc extinguishing cover (25). The inside of the spring groove (210) is connected to one end of the spring (211). The other end of the spring (211) is equipped with a locking frame (212). The locking groove (213) is opened at the ends of the left and right sides of the shell (1).
4. A circuit breaker protected against breakdown according to claim 1, characterized in that: The heat dissipation unit (3) includes a heat-conducting plate (31), a heat sink (32), a mounting bracket (33), and a placement slot (34). The placement slot (34) is opened on the inner wall of the device slot (4). The heat-conducting plate (31) is snapped into the inside of the placement slot (34). The end of the heat-conducting plate (31) is in contact with the heat sink (32). The mounting bracket (33) is fixed to the side of the housing (1). The heat sink (32) is installed inside the mounting bracket (33).
5. A circuit breaker protected against breakdown according to claim 1, characterized in that: It also includes a transparent window (8), a limiting plate (9) and a limiting groove (10). The transparent window (8) is opened on both sides of the top surface of the shell cover (6). There are two limiting plates (9) and they are fixed to the bottom surface of the shell cover (6) on the left and right respectively. There are two limiting grooves (10) and they are respectively opened on the top surface of the shell (1). The limiting plate (9) and the limiting groove (10) are inserted into each other.
6. A circuit breaker protected against breakdown according to claim 1, characterized in that: It also includes an arc-extinguishing coating (11), which is uniformly coated on the inner surfaces of the housing (1) and the cover (6), and the arc-extinguishing coating (11) is a polyimide coating.