A miniature circuit breaker

Abstract

The application discloses a small circuit breaker, comprising: a circuit breaker shell, a terminal is arranged in the circuit breaker shell; an insertable straight plate, which is arranged in the circuit breaker shell in a plug-in manner; a reed, which is installed on the insertable straight plate, and which is in elastic contact with the terminal for power supply; a cylindrical mounting cylinder, which is integrally arranged with the reed; an NTC temperature measuring element, which is installed in the cylindrical mounting cylinder; and a glue filling, which is filled in the cylindrical mounting cylinder to package the NTC temperature measuring element; wherein the reed forms an electrical connection with the terminal through elastic deformation, and the cylindrical mounting cylinder forms a heat conduction path with the terminal through the reed. The application has the following beneficial effects: through the plug-in connection structure and the integrated temperature measurement design, the welding-free installation and high-precision temperature monitoring are realized, and the installation convenience and temperature measurement precision are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, and more specifically to a miniature circuit breaker. Background Technology

[0002] Miniature circuit breakers (MCBs) play a crucial role as essential protective devices in low-voltage power distribution systems, particularly in residential, commercial, and industrial applications. With the increasing intelligence of electrical equipment and ever-improving safety requirements, the functions and performance of MCBs are continuously being enhanced. Modern MCBs not only need to provide basic overload and short-circuit protection but also require intelligent functions such as temperature monitoring, status indication, and remote control to meet the complex needs of modern power distribution systems.

[0003] Currently, the market offers a wide variety of miniature circuit breakers (MCBs), including products with different numbers of poles and tripping characteristics, capable of adapting to various complex power distribution environments and load conditions. With the development of IoT technology and smart grids, some advanced MCBs can even achieve functions such as remote monitoring, fault diagnosis, and preventative maintenance. Furthermore, the manufacturing process of MCBs is constantly being optimized, significantly improving product reliability and lifespan, providing strong support for the safe and stable operation of electrical systems.

[0004] However, despite continuous advancements in miniature circuit breaker (MCB) technology, several pressing issues remain in practical applications. Existing MCBs require welding to connect both terminals to electrical wires during installation and maintenance, a cumbersome process demanding specialized expertise. Furthermore, due to internal space constraints and the instability of the potting process, the integrated NTC temperature sensing element suffers from uncontrollable temperature measurement errors. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a miniature circuit breaker that achieves welding-free installation and high-precision temperature monitoring through a pluggable connection structure and integrated temperature measurement design, thereby significantly improving installation convenience and temperature measurement accuracy.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A miniature circuit breaker includes: a circuit breaker housing with terminals disposed within it; an insertable straight plate removably disposed within the circuit breaker housing; a spring plate mounted on the insertable straight plate, the spring plate making elastic contact with the terminals for energization; a cylindrical mounting sleeve integrally formed with the spring plate; an NTC temperature sensing element mounted within the cylindrical mounting sleeve; and potting compound filling the cylindrical mounting sleeve to encapsulate the NTC temperature sensing element; wherein the spring plate forms an electrical connection with the terminals through elastic deformation, and the cylindrical mounting sleeve forms a heat conduction path with the terminals through the spring plate.

[0008] The present invention is further configured as follows:

[0009] The insertable straight plate includes an insertion part and a connecting part. The insertion part is pluggably fitted into the circuit breaker housing, and the connecting part is disposed outside the circuit breaker housing for connecting wires.

[0010] The spring is a metal elastic sheet structure, and the spring has a preset elastic deformation amount to ensure the contact pressure with the terminal;

[0011] The cylindrical mounting tube is integrally formed with the spring, and the cylindrical mounting tube has a standardized internal volume;

[0012] The NTC temperature sensing element is connected to an external temperature monitoring circuit via a wire, which passes through the open end of the cylindrical mounting tube.

[0013] The potting compound is a thermally conductive and insulating adhesive, and the amount of potting compound used is determined by the standardized volume of the cylindrical mounting tube.

[0014] The reed includes a contact section and a connecting section, the contact section being in contact with the terminal, and the connecting section being connected to the cylindrical mounting cylinder;

[0015] A positioning structure is provided between the insertion part and the circuit breaker housing, and the positioning structure ensures the correct insertion position of the insertable straight plate;

[0016] The terminal is a screw terminal or a pressure plate terminal, and the contact area of ​​the spring is matched with the contact area of ​​the terminal;

[0017] The standardized volume of the cylindrical mounting tube ensures that the amount of adhesive used in multiple miniature circuit breakers remains consistent, and the NTC temperature sensing element compensates for the impact of adhesive quantity error on temperature measurement accuracy through resistance adjustment.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] Significantly improved installation convenience: The pluggable connection structure replaces the traditional welding process, eliminating the need for professional welding equipment and techniques, increasing installation efficiency by more than 70%, avoiding the risks of heat damage and welding defects during the welding process, and greatly simplifying the installation process and technical requirements.

[0020] Maintenance efficiency is greatly improved: in case of failure, it can be quickly disassembled and replaced without the need for desoldering and rewiring, reducing maintenance time by 80%, reducing power outage time and maintenance costs, and significantly improving the maintainability and operational continuity of the system.

[0021] Significantly improved temperature measurement accuracy: The standardized cylindrical mounting tube ensures consistent glue application, and the integrated design of the spring and mounting tube enables direct heat conduction. Temperature measurement error control accuracy is improved by more than 50%, and temperature response time is shortened by 30-40%, greatly improving the accuracy and timeliness of temperature protection.

[0022] Effective reduction in manufacturing costs: Eliminating welding processes reduces equipment and labor costs, and standardized design reduces the difficulty of quality control. Manufacturing costs are reduced by 15-20%, and quality control costs are reduced by 25%, significantly improving the economic efficiency and competitiveness of the product.

[0023] Product reliability has been comprehensively improved: the elastic contact of the spring eliminates corrosion and aging problems at the welding points, improves connection reliability by more than 30%, reduces contact resistance and heat generation risk, and significantly improves the overall reliability and stability of the system. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below:

[0025] Figure 1 This is a schematic diagram of the overall structure of the miniature circuit breaker of the present invention;

[0026] Figure 2 This is a schematic diagram of the insertable straight plate and spring structure of the miniature circuit breaker of the present invention after removing the side plate;

[0027] Figure 3 for Figure 2 A schematic diagram showing the state of the insertable straight plate when it is pulled out;

[0028] Figure 4 This is a schematic diagram showing the connection relationship between the reed and the cylindrical mounting sleeve.

[0029] Figure 5 for Figure 4 A schematic diagram of the rear view structure.

[0030] Reference numerals: 1. Circuit breaker housing; 2. Terminal; 3. Insertable straight plate; 4. Spring; 5. Cylindrical mounting tube; 6. NTC temperature sensing element; 7. Potting compound; 8. Insertion part; 9. Connection part; 10. Wire; 11. Contact section; 12. Connection section; 13. Positioning structure. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] like Figure 1 As shown, the present invention provides a miniature circuit breaker, which mainly includes a circuit breaker housing 1, a pluggable connection system and an integrated temperature measurement system.

[0033] The circuit breaker housing 1 adopts a standard miniature circuit breaker housing structure, with terminals 2 installed inside. Terminals 2 can be screw terminals or pressure plate terminals, used to form a conductive path with internal electrical connection elements. An insertable straight plate 3 is detachably installed inside the circuit breaker housing 1, enabling a detachable connection between external wires and internal terminals 2.

[0034] like Figure 2 and Figure 3 As shown, the insertable straight plate 3 includes an insertion part 8 and a connecting part 9. The insertion part 8 is pluggably fitted into the circuit breaker housing 1, achieving a stable mechanical connection through precise geometric fit. The connecting part 9 is located near the outer side of the circuit breaker housing 1 and is used to connect a circuit board.

[0035] The spring 4 is mounted on the insertable straight plate 3 and is a metal elastic sheet structure with a preset elastic deformation amount. The spring 4 makes elastic contact with the terminal 2 to conduct electricity, and forms a reliable electrical connection with the terminal 2 through elastic deformation, ensuring the contact pressure and conductivity with the terminal 2.

[0036] like Figure 4 , Figure 5 As shown, the reed 4 includes a contact section 11 and a connecting section 12. The contact section 11 contacts the terminal 2, and the contact area matches the contact area of ​​the terminal 2 to ensure sufficient electrical contact. The connecting section 12 connects to the cylindrical mounting cylinder 5, realizing the structural integration of electrical connection and temperature measurement functions.

[0037] The elastic properties of spring 4 can compensate for manufacturing and assembly errors, ensuring a stable electrical connection under different operating conditions. The elastic contact method avoids problems such as corrosion and aging that may occur with welded connections, significantly improving the long-term reliability of the connection.

[0038] The cylindrical mounting tube 5 and the spring 4 are integrated into one unit, forming a dual-function integrated structure for electrical connection and temperature monitoring. The cylindrical mounting tube 5 has a standardized internal volume, ensuring the consistency of the amount of adhesive 7 applied during mass production.

[0039] The NTC temperature sensing element 6 is installed inside the cylindrical mounting tube 5 and connected to an external temperature monitoring circuit via a wire 10. The wire 10 passes through the open end of the cylindrical mounting tube 5 for easy connection to the external circuit. The potting compound 7 is a thermally conductive and insulating adhesive that fills the cylindrical mounting tube 5 to encapsulate and protect the NTC temperature sensing element 6.

[0040] The cylindrical mounting tube 5 forms a direct heat conduction path with the terminal 2 through the spring 4. When the terminal 2 heats up due to the current passing through it, the heat is directly conducted to the cylindrical mounting tube 5 through the spring 4, and then transferred to the NTC temperature sensing element 6 inside, realizing real-time monitoring of the temperature of the terminal 2.

[0041] This direct heat conduction design eliminates the thermal resistance of traditional multi-layer heat transfer structures, significantly improving temperature response speed and measurement accuracy. The integrated design of the reed 4 and the mounting cylinder ensures the stability and reliability of the heat conduction path.

[0042] like Figure 2 , Figure 3 As shown, a positioning structure 13 is provided between the insertion part 8 and the circuit breaker housing 1 to ensure the correct insertion position of the insertable straight plate 3. The positioning structure 13 includes geometric features such as guide grooves and limiting bosses to prevent positional deviation and reverse insertion during the insertion process.

[0043] The precise design of the positioning structure 13 ensures accurate alignment between the spring 4 and the terminal 2, guaranteeing the reliability of the electrical connection. Simultaneously, the positioning structure 13 also features an anti-misinsertion function, preventing operational errors during installation.

[0044] The standardized volume design of the cylindrical mounting tube 5 ensures consistent glue application 7 across multiple miniature circuit breakers, fundamentally solving the temperature measurement error problem caused by unstable glue application 7 in traditional processes. The glue application 7 is precisely determined by the standardized volume of the cylindrical mounting tube 5, guaranteeing process reproducibility and product quality consistency.

[0045] The NTC temperature sensing element 6 compensates for the impact of potting quantity error 7 on temperature measurement accuracy through resistance adjustment, further improving the accuracy and stability of the temperature measurement system. This design allows for effective compensation through resistance adjustment even with minor process variations.

[0046] Based on the technical effects described in this invention, this invention focuses on verifying the performance improvement of the pluggable connection structure of miniature circuit breakers in terms of installation convenience, maintenance efficiency, temperature measurement accuracy, manufacturing cost, and product reliability.

[0047] A comparative experiment was conducted using standard distribution cabinet installation procedures, with the test conditions being the installation of 20A rated current miniature circuit breakers. The comparison sample consisted of 20 traditional welded circuit breakers and 20 new pluggable circuit breakers, with continuous testing for 30 days.

[0048] Main test items:

[0049] Ease of installation test: measurement of installation time and assessment of skill requirements;

[0050] Maintenance efficiency assessment: Statistics on disassembly and replacement time under fault simulation;

[0051] Temperature measurement accuracy test: comparative analysis of temperature response time and measurement error;

[0052] Manufacturing cost analysis: Cost accounting for process steps and equipment input;

[0053] Reliability verification: contact resistance measurement and long-term stability assessment.

[0054] 2. Technical Effect Comparison Table

[0055]

[0056] 3. Verification Conclusion

[0057] Through comprehensive comparative verification experiments, the pluggable miniature circuit breaker of this invention achieves significant improvements in all key performance indicators:

[0058] Improved installation convenience: The pluggable connection structure changes the traditional circuit breaker installation mode, increasing installation efficiency by 73%, reducing the average installation time from 15 minutes to 4 minutes. No specialized welding equipment or techniques are required, significantly lowering the installation threshold and technical requirements. Field tests show that ordinary electricians can complete the installation work, avoiding heat damage and quality risks during welding.

[0059] Maintenance efficiency: The quick disassembly and replacement function in case of failure reduces maintenance time by 80%, from 25 minutes to 5 minutes. This reduces power outage time and economic losses, and improves the maintainability and operational continuity of the power supply system.

[0060] Temperature measurement performance: The standardized cylindrical mounting tube ensures consistent glue application. Combined with the direct heat conduction path of the integrated design of the spring and mounting tube, the temperature measurement accuracy is improved by 50%, and the error is reduced from ±3℃ to ±1.5℃. The temperature response time is improved by 33%, from 45 seconds to 30 seconds, providing more accurate and timely data support for the temperature protection function.

[0061] Economic benefits: Eliminating the welding process brings significant cost advantages, reducing manufacturing costs by 15%, while standardized design simplifies quality control. Long-term operating cost analysis shows that the substantial reduction in maintenance costs results in a clear advantage in total cost of ownership.

[0062] Reliability: The spring-loaded elastic contact mechanism eliminates the corrosion and aging problems of traditional solder joints, reducing contact resistance from 0.8mΩ to 0.5mΩ and improving connection reliability by 38%. Long-term stability tests show that the pluggable connection maintains stable electrical performance under various operating conditions.

[0063] Technological Innovation Value: This invention solves the industry problems of complex installation and low temperature measurement accuracy of miniature circuit breakers by integrating the reed and the mounting cylinder, providing a new solution for the development of circuit breaker technology and possessing broad prospects for industrial application.

[0064] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0065] However, the above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A miniature circuit breaker, characterized in that, include: Circuit breaker housing (1), wherein terminals (2) are provided inside the circuit breaker housing (1); A straight plate (3) can be inserted and is detachably disposed inside the circuit breaker housing (1); A spring (4) is installed on the insertable straight plate (3), and the spring (4) is in elastic contact with the terminal (2) to conduct electricity; The cylindrical mounting tube (5) is integrally formed with the spring (4), and the cylindrical mounting tube (5) has a standardized internal volume; The NTC temperature sensing element (6) is installed inside the cylindrical mounting tube (5); Encapsulation (7) is performed by filling the cylindrical mounting tube (5) with potting compound to encapsulate the NTC temperature sensing element (6); The spring (4) forms an electrical connection with the terminal (2) through elastic deformation, and the cylindrical mounting tube (5) forms a heat conduction path with the terminal (2) through the spring (4); the standardized internal volume of the cylindrical mounting tube (5) ensures that the amount of glue (7) of multiple miniature circuit breakers is consistent, and the NTC temperature measuring element (6) compensates for the influence of glue amount error on temperature measuring accuracy through resistance adjustment.

2. The miniature circuit breaker according to claim 1, characterized in that, The insertable straight plate (3) includes an insertion part (8) and a connecting part (9). The insertion part (8) is pluggably fitted inside the circuit breaker housing (1), and the connecting part (9) is disposed outside the circuit breaker housing (1) for connecting wires.

3. The miniature circuit breaker according to claim 1, characterized in that, The spring (4) is a metal elastic sheet structure, and the spring (4) has a preset elastic deformation amount to ensure the contact pressure with the terminal (2).

4. The miniature circuit breaker according to claim 1, characterized in that, The NTC temperature sensing element (6) is connected to an external temperature monitoring circuit via a wire (10), which passes through the open end of the cylindrical mounting tube (5).

5. The miniature circuit breaker according to claim 1, characterized in that, The potting compound (7) is a thermally conductive insulating compound, and the amount of the potting compound (7) is determined by the standardized volume of the cylindrical mounting tube (5).

6. The miniature circuit breaker according to claim 1, characterized in that, The reed (4) includes a contact section (11) and a connecting section (12). The contact section (11) contacts the terminal (2), and the connecting section (12) is connected to the cylindrical mounting tube (5).

7. The miniature circuit breaker according to claim 2, characterized in that, A positioning structure (13) is provided between the insertion part (8) and the circuit breaker housing (1), and the positioning structure (13) ensures the correct insertion position of the insertable straight plate (3).

8. The miniature circuit breaker according to claim 1, characterized in that, The terminal (2) is a screw terminal or a pressure plate terminal, and the contact area of ​​the spring (4) matches the contact area of ​​the terminal (2).

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