Molded case circuit breaker with stable sealing effect

Abstract

The invention relates to the related technical field of molded case circuit breakers, and discloses a molded case circuit breaker with a stable sealing effect, and the molded case circuit breaker comprises a plastic case which integrally comprises a front cover case and a rear cover case, and a water sensing detection assembly is arranged between the front cover case and the rear cover case. An explosion-proof box assembly and an explosion-proof chamber water collecting device are arranged in the front cover shell and the rear cover shell; the water sensing detection assembly is used for detecting the sealing performance of the front cover shell and the rear cover shell when the sealing performance of the front cover shell and the rear cover shell is poor. Dual foundation protection of sealing monitoring and initial water vapor adsorption is achieved through the water sensing detection assembly, the assembly is deployed at the joint of the front cover shell and the rear cover shell, the change of a shell sealing gap can be sensed in real time, the sealing failure risk can be recognized in time, meanwhile, the assembly can rapidly complete adsorption for a small amount of permeated water vapor, and the water sensing detection assembly is convenient to use. The path of water vapor contacting with the internal conductive component is cut off from the source, thereby avoiding the primary short-circuit hidden danger.

Description

Technical Field

[0001] This invention belongs to the technical field of molded case circuit breakers, and more specifically, relates to a molded case circuit breaker with stable sealing effect. Background Technology

[0002] In power distribution systems, molded case circuit breakers (MCCBs) are widely used in complex operating conditions such as outdoor meter boxes and industrial distribution boxes, serving as core devices for overload and short-circuit protection. However, with the expansion of outdoor power usage scenarios, the shortcomings of traditional MCBs in terms of sealing and moisture protection have become increasingly apparent, becoming a major cause of circuit failures.

[0003] Traditional molded case circuit breakers typically rely solely on sealing rings at the casing connections for sealing protection. Over time, these rings are susceptible to wear and loosening due to environmental vibrations and aging, leading to increased gaps in the casing and allowing external moisture to easily seep in. Since the circuit breaker lacks a dedicated moisture monitoring and adsorption structure, the infiltrated moisture directly contacts conductive components, fuses, and other core components. This not only degrades the insulation performance of these components but also easily triggers short circuits, and in severe cases, electric arcs, potentially causing casing explosions, fires, and other major safety accidents. Furthermore, while some existing circuit breakers incorporate individual moisture-absorbing components, they lack centralized moisture storage and risk warning mechanisms, making it difficult to accurately assess the level of moisture accumulation and trigger emergency protection actions. Additionally, traditional arc-quenching expansion agents only have a single arc-quenching function and cannot meet the insulation protection requirements under humid fault conditions, making it difficult to guarantee the operational safety and stability of the circuit breaker in humid environments.

[0004] Therefore, in view of this, we have studied and improved the existing structure and its shortcomings to provide a molded case circuit breaker with stable sealing effect, in order to achieve a more practical and valuable purpose. Summary of the Invention

[0005] This invention provides a molded case circuit breaker with stable sealing performance to overcome the above-mentioned defects in the prior art.

[0006] The purpose and effect of this invention, which provides a molded case circuit breaker with stable sealing performance, are achieved by the following specific technical means: A molded case circuit breaker with stable sealing effect includes an integral plastic case, the integral plastic case including a front cover and a rear cover, a water-sensing detection component is provided between the front cover and the rear cover, and an explosion-proof box assembly and an explosion-proof chamber water collection device are provided inside the front cover and the rear cover. The water-sensing detection component is used to detect the sealing performance between the front cover and the rear cover. When the sealing performance between the front cover and the rear cover is insufficient, the water-sensing detection component can be used to adsorb water vapor to prevent water vapor from condensing and dripping, causing an internal short circuit. The explosion-proof box assembly is filled with a modified graphite expanding agent. The explosion-proof chamber water collection device works in conjunction with the water sensing component to adsorb and transfer water vapor. When the water inside the explosion-proof chamber water collection device is condensed to a certain amount, the modified graphite expanding agent filled inside the explosion-proof box assembly will be activated to expand and insulate.

[0007] A further technical solution is that the plastic shell as a whole includes a front cover shell, a water sensing component is connected between the front cover shell and the rear cover shell, a back isolation ceramic plate and a middle ceramic isolation plate are fixedly installed inside the front cover shell and the rear cover shell, the back isolation ceramic plate and the middle ceramic isolation plate divide the interior of the front cover shell and the rear cover shell into a power connection cavity, a power isolation cavity and a detection expansion cavity, the power connection cavity is located behind the power isolation cavity and the detection expansion cavity, and the power isolation cavity is located to the left of the detection expansion cavity.

[0008] In a further technical solution, a conductive component is installed inside the power connection cavity. The conductive component includes an upper conductive plate and a lower conductive plate, with a gap between the upper conductive plate and the lower conductive plate. A safety brake component is fixedly installed in the gap.

[0009] In a further technical solution, the safety gate assembly is disposed in the power isolation cavity. The safety gate assembly includes a ceramic insulating isolation frame. An upper connection member and a lower connection member are fixedly installed on the ceramic insulating isolation frame from top to bottom. A tripping actuator is rotatably provided between the upper connection member and the lower connection member. A connecting swing member is connected to the outside of the tripping actuator. An interlocking mechanism is fixedly connected to the end of the connecting swing member. A hook spring is fixedly connected to the outside of the interlocking mechanism. An arc-shaped operating handle is fixedly connected to the output end of the interlocking mechanism. A ceramic insulating tube is connected to the outer end of the upper connection member. The ceramic insulating tube is connected to the explosion-proof box assembly.

[0010] A further technical solution involves fixing an explosion-proof box assembly and an explosion-proof chamber water collection device inside the detection expansion chamber. The explosion-proof box assembly includes an inductive heating wire assembly and an expansion agent container. The expansion agent container is L-shaped, with a cavity inside the horizontal and vertical sections of the L-shape. The cavity contains a modified graphite expansion agent. Several injection ports are arrayed on the outer side of the expansion agent container. An installation cavity is provided inside the vertical section of the L-shape, and an inductive heating wire assembly is fixedly installed inside the installation cavity. An explosion-proof chamber water collection device is fixedly installed above the explosion-proof box assembly.

[0011] A further technical solution includes a fixed isolation plate for the explosion-proof chamber water collection device. The fixed isolation plate is fixedly connected to the back isolation ceramic plate. A rubber base is fixedly installed on the fixed isolation plate. A water collection cylinder is fixedly connected to the rubber base. A paraffin blocker and an adsorption conduit are fixedly installed on the outside of the water collection cylinder. The paraffin blocker is fixedly connected to the explosion-proof box assembly. The adsorption conduit is fixedly connected to the central detection assembly. A detection probe is fixedly installed above the water collection cylinder. A water-sensing probe is provided at the end of the detection probe. The end of the water-sensing probe extends through into the interior of the water collection cylinder. A cavity is installed inside the water collection cylinder, and water-absorbing granular balls are provided in the cavity.

[0012] A further technical solution is that the raw material ratio of the water-absorbing granules is: 75% anhydrous calcium chloride and 25% expanded graphite. The water-absorbing granules have both moisture absorption and moisture-proof functions as well as arc-extinguishing auxiliary functions.

[0013] A further technical solution involves the following raw material ratio for the modified graphite expander: 88% expanded graphite, 10% graphene microsheets, and 2% zinc borate. During preparation, the three raw materials are mixed and then expanded at 800-900℃ for 15-20 seconds in an inert gas atmosphere. After cooling, the mixture is sieved (100-200 mesh) to obtain a modified expander with a higher expansion ratio and stronger insulation properties, which also possesses rapid arc extinguishing, insulation isolation, and explosion-proof buffering functions.

[0014] A further technical solution is provided with a detection protection cover assembly on the surface of the front cover shell. The detection protection cover assembly includes an observation protection cover. The surface of the observation protection cover is provided with an observation window and a detection probe. A rectangular opening is provided on the left side of the observation window. The interlocking mechanism is inserted into the rectangular opening. The detection probe is installed in the detection probe.

[0015] A further technical solution is that the back cover is provided with a back mounting plate, and an end waterproof detection component is provided at the connection between the back mounting plate and the back cover.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a molded case circuit breaker with stable sealing performance. By incorporating a water-sensing detection component, the component provides dual basic protection: seal monitoring and initial moisture adsorption. Deployed at the connection between the front and rear covers, this component can detect changes in the housing seal gap in real time, promptly identifying the risk of seal failure. Simultaneously, for any small amount of moisture that has already seeped in, the component can quickly adsorb it, cutting off the path of moisture to the internal conductive components at the source and preventing primary short circuits. This basic protection reduces the burden on subsequent protection structures and strengthens the overall protection system from the outset, significantly reducing the initial probability of circuit failures caused by moisture.

[0017] This invention provides a molded case circuit breaker with stable sealing performance through an explosion-proof chamber water collection device. This device achieves advanced centralized storage and visual early warning of water vapor. Furthermore, the device is connected to a water-sensing detection component via an adsorption conduit, enabling the unified collection of incompletely adsorbed water vapor, preventing its dispersion and spread within the casing. The internal water-absorbing granules efficiently store water vapor, while the three-color water sensor at the top displays green, yellow, and red indicators based on the water level, providing a clear early warning of water vapor accumulation. This design not only solves the problem of difficult-to-control dispersed water vapor but also provides precise activation criteria for subsequent ultimate protection, ensuring the timeliness and rationality of protective actions.

[0018] This invention provides a molded case circuit breaker with stable sealing performance through an explosion-proof box assembly. This assembly provides dual protection—emergency power cut-off and full-area insulation arc extinguishing—when moisture accumulation exceeds limits. Furthermore, when the water sensor triggers a red warning, the inductor heating wire within the assembly heats up, simultaneously melting the paraffin central shaft to mechanically trip and cut off the faulty circuit. Simultaneously, the modified graphite expanding agent expands upon heating, forming an insulating carbonaceous layer through the array of injection nozzles, rapidly extinguishing the arc and isolating the faulty area, while also buffering internal pressure to prevent the casing from bursting. This effect completely eliminates major safety accidents such as fires, completing a closed-loop process from initial protection to ultimate safeguards, significantly improving the safety level of the circuit breaker. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the overall appearance and structure of the present invention; Figure 2 This is a schematic diagram of the overall front view of the present invention; Figure 3 This is a schematic diagram of the overall side view structure of the present invention; Figure 4 This is a schematic diagram of the overall internal structure of the present invention; Figure 5 This is a schematic diagram of the overall front view of the internal structure of the present invention; Figure 6 This is a schematic side view of the overall internal structure of the present invention; Figure 7This is a top view schematic diagram of the overall internal explosive structure of the present invention; Figure 8 This is a schematic side view of the overall internal explosion structure of the present invention; Figure 9 This is a schematic diagram of the overall front view of the internal explosion structure of the present invention; Figure 10 This is a first exploded structural diagram of the internal structure of the present invention; Figure 11 This is a second exploded structural diagram of the internal structure of the present invention; Figure 12 For the present invention Figure 10 A magnified structural diagram of point A in the middle.

[0022] Figure 13 For the present invention Figure 11 A magnified structural diagram at point B in the middle.

[0023] Explanation of reference numerals in the attached figures: 1. Plastic shell assembly; 11. Front cover; 12. Rear cover; 13. Detection protection cover assembly; 131. Observation protection cover; 132. Observation window; 133. Detection probe hole; 2. Water sensor detection component; 21. Mid-section detection component; 22. End waterproof detection component; 3. Safety brake assembly; 31. Arc-shaped operating handle; 32. Interlocking mechanism; 33. Upper circuit connector; 34. Trip actuator; 35. Lower circuit connector; 36. Ceramic insulating isolation frame; 37. Ceramic insulating tube; 38. Connecting ornament; 4. Conductive components; 41. Upper conductive sheet; 42. Lower conductive sheet; 43. Middle ceramic insulating sheet; 44. Back insulating ceramic plate; 5. Explosion-proof box assembly; 51. Inductive heating wire assembly; 52. Expanding agent container; 6. Explosion-proof chamber water collection device; 61. Fixed isolation plate; 62. Rubber base; 63. Water collection cylinder; 64. Paraffin blocker; 65. Water sensor probe; 66. Detection probe; 67. Adsorption conduit. Detailed Implementation

[0024] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0025] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] As attached Figure 1 To be continued Figure 13 As shown: The present invention provides a molded case circuit breaker with stable sealing effect, comprising a plastic case 1, wherein the plastic case 1 comprises a front cover 11 and a rear cover 12, a water sensor 2 is provided between the front cover 11 and the rear cover 12, and an explosion-proof box assembly 5 and an explosion-proof chamber water collection device 6 are provided inside the front cover 11 and the rear cover 12. The water-sensing detection component 2 is used to detect the sealing performance of the front cover 11 and the rear cover 12. When the sealing performance of the front cover 11 and the rear cover 12 is insufficient, the water-sensing detection component 2 can be used to adsorb water vapor to prevent water vapor from condensing and dripping, causing internal short circuits. Through its double-layer detection and adsorption structure, compared with the traditional circuit breaker housing connection relying solely on sealing rings, it can provide early warning of sealing failure risks and simultaneously achieve water vapor pre-adsorption, reducing the risk of internal short circuits by more than 80% from the source. The explosion-proof box assembly 5 is filled with a modified graphite expanding agent. The explosion-proof chamber water collection device 6 and the water sensing detection component 2 work together to form a water vapor adsorption and transfer system. When the water inside the explosion-proof chamber water collection device 6 is condensed to a certain amount, the modified graphite expanding agent filled inside the explosion-proof box assembly 5 will be activated to expand and insulate. The water vapor linkage protection system formed by the two can realize the whole process protection from water vapor detection and adsorption to emergency insulation, and improve the operating stability of the circuit breaker under humid conditions.

[0028] Preferred options are shown in the appendix. Figure 1 To be continued Figure 3The plastic shell 1 includes a front cover 11, and a water-sensing detection component 2 is connected between the front cover 11 and the rear cover 12. A back isolation ceramic plate 44 and a middle ceramic isolation plate 43 are fixedly installed inside the front cover 11 and the rear cover 12. The back isolation ceramic plate 44 and the middle ceramic isolation plate 43 divide the interior of the front cover 11 and the rear cover 12 into a power connection cavity, a power isolation cavity, and a detection expansion cavity. The power connection cavity is located behind the power isolation cavity and the detection expansion cavity, and the power isolation cavity is located to the left of the detection expansion cavity. This cavity partitioning structure uses ceramic isolation components to divide the area, which not only has excellent insulation and heat insulation performance, but also enables the independent operation of each functional cavity, avoiding interference between different cavities. Compared with the traditional integrated cavity design, its insulation protection level can be improved to IP65, while reducing the probability of arc propagation.

[0029] Preferred options are shown in the appendix. Figure 4 The power connection cavity is equipped with a conductive component 4, which includes an upper conductive plate 41 and a lower conductive plate 42. A gap is provided between the upper conductive plate 41 and the lower conductive plate 42. A fuse assembly 3 is fixedly installed in the gap. This gap-type conductive structure, together with the fuse assembly 3, can realize stable circuit conduction and emergency tripping. The gap between the upper conductive plate 41 and the lower conductive plate 42 is designed to provide sufficient space for the tripping action of the fuse assembly 3, ensuring that the power failure response time is controlled within 50ms, and improving the timeliness of circuit overload and short circuit protection.

[0030] Preferred options are shown in the appendix. Figure 6 To be continued Figure 8 The safety gate assembly 3 is disposed in the power isolation cavity. The safety gate assembly 3 includes a ceramic insulating isolation frame 36. The ceramic insulating isolation frame 36 is fixedly installed with an upper circuit connector 33 and a lower circuit connector 35 from top to bottom. A tripping actuator 34 is rotatably connected between the upper circuit connector 33 and the lower circuit connector 35. A connecting swing member 38 is connected to the outside of the tripping actuator 34. An interlocking mechanism 32 is fixedly connected to the end of the connecting swing member 38. A hook spring is fixedly connected to the outside of the interlocking mechanism 32. An arc-shaped spring is fixedly connected to the output end of the interlocking mechanism 32. The curved operating handle 31 has a ceramic insulating tube 37 connected to the outer end of the upper connecting member 33. The ceramic insulating tube 37 is connected to the explosion-proof box assembly 5. The safety gate assembly 3 adopts a mechanical linkage tripping structure, which, together with the protection of the ceramic insulating isolation frame 36, ensures the accuracy of mechanical action and avoids the burning of linkage components by electric arc. Its tripping success rate can reach 99.9%, and the number of times the components can withstand electric arc erosion is increased to more than 3 times that of traditional structures. At the same time, the design of the curved operating handle 31 makes it easy for operators to manually reset or cut off the power in an emergency, improving the ease of operation of the device.

[0031] Preferred options are shown in the appendix. Figure 5 The explosion-proof box assembly 5 and the explosion-proof chamber water collection device 6 are fixedly installed inside the detection expansion chamber. The explosion-proof box assembly 5 includes an inductive heating wire assembly 51 and an expansion agent container 52. The expansion agent container 52 is an L-shaped container with a cavity inside the horizontal and vertical sections of the L-shape. The cavity contains a modified graphite expansion agent. Several spray nozzles are arrayed on the outer side of the expansion agent container 52. An installation cavity is provided inside the vertical section of the L-shape. The inductive heating wire assembly 51 is fixedly installed inside the installation cavity. The explosion-proof chamber water collection device 6 is fixedly installed above the explosion-proof box assembly 5. The L-shaped expansion agent container 52 realizes the spatial integration of expansion agent storage and heating component installation. Its arrayed spray nozzles can ensure that the modified graphite expansion agent evenly covers the protected area after expansion. Compared with a single spray nozzle design, the protective coverage area is increased by 2.5 times. The inductive heating wire assembly 51 can achieve precise temperature control heating, ensuring that the expansion agent starts to expand synchronously at the set temperature, improving the consistency of the protective action.

[0032] Preferred options are shown in the appendix. Figure 13 The explosion-proof chamber water collection device 6 includes a fixed isolation plate 61, which is fixedly connected to the back isolation ceramic plate 44. A rubber base 62 is fixedly installed on the fixed isolation plate 61, and a water collection cylinder 63 is fixedly connected to the rubber base 62. A paraffin wax blocker 64 and an adsorption conduit 67 are fixedly installed on the outside of the water collection cylinder 63. The paraffin wax blocker 64 is fixedly connected to the explosion-proof box assembly 5, and the adsorption conduit 67 is fixedly connected to the middle detection assembly 21. A detection probe 66 is fixedly installed above the water collection cylinder 63, and a water-sensing probe 65 is provided at the end of the detection probe 66. The end of the water sensor 65 extends into the water collection cylinder 63, which has a cavity inside. Water-absorbing granules are placed inside the cavity. The explosion-proof chamber water collection device 6 forms a water vapor linkage transfer with the water sensor detection component 2 through the adsorption conduit 67. The water-absorbing granules can achieve efficient adsorption and storage of water vapor. The three-color warning function of the water sensor 65 (green for dryness, yellow for moderate water level, and red for submerged water level) allows operators to intuitively grasp the internal water vapor status, facilitating early maintenance. Simultaneously, the paraffin blocker 64 enables precise triggering of the explosion-proof box component 5, preventing accidental activation of the expanding agent and improving the safety of the device operation.

[0033] Preferred options are shown in the appendix. Figure 13The water-absorbing granules are formulated with the following raw material ratio: 75% anhydrous calcium chloride and 25% expanded graphite. These granules combine moisture absorption and moisture-proofing with arc-extinguishing auxiliary functions. With this ratio, the anhydrous calcium chloride can achieve efficient moisture absorption, and the 25% expanded graphite can solve the problem of calcium chloride easily clumping after absorbing moisture. At the same time, it can assist in arc extinguishing when an electric arc is generated. Its moisture absorption capacity can reach 1.2 times its own weight, and it can quickly form a local insulating layer in a high-temperature electric arc environment. Compared with calcium chloride moisture-absorbing material alone, its comprehensive protective performance is improved by more than 60%.

[0034] Preferred options are shown in the appendix. Figure 5 The modified graphite expander has the following raw material ratio: 88% expanded graphite, 10% graphene microflakes, and 2% zinc borate. During preparation, the three raw materials are mixed and expanded at 800-900℃ for 15-20 seconds in an inert gas atmosphere. After cooling, it is sieved through a 100-200 mesh sieve to obtain a modified expander with a higher expansion ratio and stronger insulation properties. It also possesses rapid arc extinguishing, insulation isolation, and explosion-proof buffering functions. The added graphene microflakes in this modified graphite expander ratio enhance the structural strength and insulation performance after expansion, while zinc borate provides flame retardant and arc-suppressing effects. Its expansion ratio can reach 1.8 times that of traditional expanded graphite, and its insulation resistance after expansion can reach 10 Ω·cm. 6 With an Ω or higher, it can achieve millisecond-level arc extinguishing and absorb internal pressure, reducing the risk of shell bursting. Compared with traditional expansion agents, its comprehensive protection effect is improved by more than 3 times.

[0035] Preferred options are shown in the appendix. Figure 5 The front cover 11 is provided with a detection protection cover assembly 13. The detection protection cover assembly 13 includes an observation protection cover 131. The observation protection cover 131 is provided with an observation window 132 and a detection probe hole 133. The observation window 132 has a rectangular opening on its left side. The interlocking mechanism 32 is inserted into the rectangular opening. The detection probe 66 is installed in the detection probe hole 133. The detection protection cover assembly 13 can protect the interlocking mechanism 32 and the detection probe 66 from external dust and moisture corrosion. The observation window 132 allows the operator to view the working status of the interlocking mechanism 32 in real time. The detection probe hole 133 ensures the stable installation of the detection probe 66, improving the protection of the device and the convenience of observation.

[0036] Preferred options are shown in the appendix. Figure 4 The back cover 12 is provided with a back mounting plate. An end waterproof detection component 22 is provided at the connection between the back mounting plate and the back cover 12. The back mounting plate facilitates the quick and easy installation of the device. The end waterproof detection component 22 and the middle detection component 21 form a full-circumference sealing detection, realizing waterproof monitoring at the connection of the shell without dead angles. Compared with the single-sided detection structure, the detection rate of sealing failure is increased to 100%, further ensuring the safe operation of the device in complex environments such as outdoors.

[0037] Specific usage of this invention: When using this device, first install it in the outdoor meter box, then connect the corresponding power cord to the upper conductive plate 41 and lower conductive plate 42 of the power connection cavity to complete the basic assembly for circuit conduction. Compared with traditional circuit breakers, the back mounting plate of this device can be quickly snapped and fixed, improving installation efficiency by 50%. In addition, the end waterproof detection component 22 can monitor the sealing status of the back at the beginning of installation, thus building a strong waterproof defense from the installation stage.

[0038] When this device is in use, factors such as poor sealing of the meter box surface, aging of the shell connection, or external environmental vibration may cause the gap between the front cover 11 and the rear cover 12 to increase, resulting in water vapor infiltration. Traditional circuit breakers rely solely on sealing rings for sealing, which are prone to water ingress and short circuits due to aging, leading to major safety accidents such as fires. However, the middle detection component 21 and the end waterproof detection component 22 of this device are located inside the shell connection, forming a dual protection of full-circuit sealing detection and pre-adsorption. This can not only detect sealing failure at the first time, but also adsorb the small amount of water vapor that seeps in, reducing the risk of internal short circuits by more than 80% from the source.

[0039] When water vapor drips through the gaps onto the central detection component 21, the component first isolates and adsorbs the vapor. The accumulated moisture is then transported through the adsorption conduit 67 to the inside of the water collection cylinder 63, where it is efficiently adsorbed and stored by water-absorbing granular balls (75% anhydrous calcium chloride and 25% expanded graphite). These granular balls can absorb up to 1.2 times their own weight in moisture, and the 25% expanded graphite prevents calcium chloride from clumping after absorbing moisture. Furthermore, it assists in extinguishing arcs when they are generated. Its overall protective performance is more than 60% better than that of a single calcium chloride absorbent material. As water vapor accumulates, the water level in the collection cylinder 63 gradually rises. The water sensor 65 will then issue a three-color warning based on the water level (green when dry, yellow when the water level is moderate, and red when the water level is submerged), allowing operators to visually monitor the internal moisture level and initiate maintenance work in advance.

[0040] When the water vapor inside the water collection cylinder 63 is collected to a certain amount and the water sensor 65 turns red, the detection probe 66 will send an electrical control signal to start the inductive heating wire assembly 51. After the inductive heating wire assembly 51 is started, it begins to heat up precisely. When the temperature is heated to 160°C, the heat will melt the ceramic insulating tube 37, so that the upper connection part 33 of the safety gate assembly 3 and the interior of the expansion agent container 52 form a communication channel. At the same time, the temperature will melt the paraffin blocker 64, releasing the triggering restriction on the expansion agent container 52. During this process, the paraffin central shaft on the upper connecting piece 33 will also melt simultaneously, causing the hook spring on the outside of the interlocking mechanism 32 to be in a disengaged state. The tension of the hook spring will drive the connecting swing piece 38 to move, thereby pulling the tripping actuator 34 to rotate downward, realizing the disengagement and power cut-off of the tripping actuator 34 from the upper connecting piece 33 and the lower connecting piece 35. The response time of this mechanical linkage tripping structure can be controlled within 50ms, and the tripping success rate reaches 99.9%. Moreover, the ceramic insulating isolation frame 36 can prevent arc erosion of the linkage components, and the number of arc erosion resistance of the components is more than 3 times that of the traditional structure.

[0041] After the entire equipment is powered off, the modified graphite expanding agent (88% expanded graphite, 10% graphene micro-flakes, and 2% zinc borate) in the expanding agent container 52 will enter the heating and expansion stage under the continuous heating of the inductive heating wire assembly 51. The expansion ratio of this modified expanding agent is 1.8 times that of traditional expanded graphite. After expansion, it will be uniformly sprayed outward through the array of spray nozzles on the outside of the container, and its protective coverage area is 2.5 times that of a single spray nozzle design. After spraying, the modified graphite expanding agent will quickly form a loose and porous carbonaceous layer. On the one hand, it can quickly fill the arc gap and isolate air, achieving millisecond-level arc extinguishing and effectively preventing the internal components of the circuit breaker from being burned by the arc; on the other hand, the insulation resistance of the expanded material can reach 10 Ω·cm. 6 With an expansion capacity of Ω or higher, it can temporarily isolate the fault area, preventing arc reignition or further expansion of the short circuit fault. Graphene microsheets can improve the structural strength and insulation performance of the expansion layer, while zinc borate can play an auxiliary role in flame retardancy and arc suppression. At the same time, its expansion process can absorb the internal pressure generated by the arc and high temperature, and together with the explosion-proof chamber structure, it reduces the risk of shell rupture. Compared with traditional expansion agents, its comprehensive protection effect is improved by more than 3 times, fully ensuring the operational safety of the circuit breaker under humid fault conditions.

[0042] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A molded case circuit breaker with stable sealing effect, comprising a plastic housing assembly (1), wherein the plastic housing assembly (1) includes a front cover (11) and a rear cover (12), characterized in that: A water sensor assembly (2) is provided at the connection between the front cover (11) and the rear cover (12). An explosion-proof box assembly (5) and an explosion-proof chamber water collection device (6) are provided inside the plastic shell assembly (1). The water-sensing detection component (2) is used to detect the sealing performance of the front cover (11) and the rear cover (12) and to adsorb the infiltrated water vapor; The explosion-proof chamber water collection device (6) is linked with the water sensing component (2) to realize water vapor adsorption and transfer. When the water vapor in the explosion-proof chamber water collection device (6) accumulates to a certain amount, the modified graphite expansion agent in the explosion-proof box component (5) can be triggered to complete the expansion insulation protection.

2. The molded case circuit breaker according to claim 1, characterized in that: The plastic shell (1) is internally fixed with a back isolation ceramic plate (44) and a middle ceramic isolation plate (43), which divide the internal space of the shell into a power connection cavity, a power isolation cavity and a detection expansion cavity; the power connection cavity is located behind the power isolation cavity and the detection expansion cavity, and the power isolation cavity is located to the left of the detection expansion cavity.

3. The molded case circuit breaker according to claim 2, characterized in that: The power connection cavity is equipped with a conductive component (4), which includes an upper conductive plate (41) and a lower conductive plate (42). A gap is left between the upper conductive plate (41) and the lower conductive plate (42), and a safety gate component (3) is fixed in the gap.

4. The molded case circuit breaker according to claim 3, characterized in that: The safety gate assembly (3) is located in the power isolation cavity and includes a ceramic insulating isolation frame (36). An upper connection member (33) and a lower connection member (35) are fixed on the ceramic insulating isolation frame (36) from top to bottom, and a tripping actuator (34) is rotatably connected between the two. The release actuator (34) is connected to a connecting swing piece (38) on the outside. The end of the connecting swing piece (38) is connected to a chain mechanism (32). The chain mechanism (32) is connected to a hook spring on the outside and an arc-shaped operating handle (31) at its output end. The outer end of the upper connecting piece (33) is connected to a ceramic insulating tube (37), and the ceramic insulating tube (37) is connected to the explosion-proof box assembly (5).

5. The molded case circuit breaker according to claim 4, characterized in that: An explosion-proof box assembly (5) and an explosion-proof chamber water collection device (6) are fixed inside the detection expansion chamber. The explosion-proof box assembly (5) includes an inductive heating wire assembly (51) and an L-shaped expansion agent container (52). The expansion agent container (52) has a modified graphite expansion agent built into its horizontal vertical section cavity and an array of spray nozzles on its outer side. The inductive heating wire assembly (51) is built into its vertical section mounting cavity. The explosion-proof chamber water collection device (6) is located above the explosion-proof box assembly (5).

6. The molded case circuit breaker according to claim 5, characterized in that: The explosion-proof chamber water collection device (6) includes a fixed isolation plate (61) that is fixedly connected to the back isolation ceramic plate (44), and a water collection cylinder (63) is connected to the fixed isolation plate (61) via a rubber base (62). A paraffin blocker (64) and an adsorption conduit (67) are fixed on the outside of the water collection cylinder (63). The paraffin blocker (64) is connected to the explosion-proof box assembly (5), and the adsorption conduit (67) is connected to the middle detection assembly (21) of the water sensing detection assembly (2). A detection probe (66) is fixed above the water collection cylinder (63). The water sensor (65) at the end of the detection probe (66) extends into the water collection cylinder (63). The water collection cylinder (63) contains water-absorbing granular balls.

7. The molded case circuit breaker according to claim 6, characterized in that: The water-absorbing granules are composed of 75% anhydrous calcium chloride and 25% expanded graphite by weight, and have both moisture-absorbing and moisture-proof functions as well as arc-extinguishing auxiliary functions.

8. The molded case circuit breaker according to claim 7, characterized in that: The modified graphite expander is composed of 88% expanded graphite, 10% graphene micro flakes and 2% zinc borate by weight. Its preparation process is as follows: after the raw materials are mixed, they are expanded at a high temperature of 800-900℃ for 15-20 seconds in an inert gas atmosphere, and after cooling, they are passed through a 100-200 mesh sieve. It has the functions of rapid arc extinguishing, insulation and isolation and explosion-proof buffer.

9. The molded case circuit breaker according to claim 1, characterized in that: The front cover (11) is provided with a detection protection cover assembly (13), including an observation protection cover (131), the observation protection cover (131) is provided with an observation window (132) and a detection probe (133); the observation window (132) has a rectangular opening on the left side with an interlocking mechanism (32), and the detection probe (133) has a built-in detection probe (66).

10. The molded case circuit breaker according to claim 1, characterized in that: The back cover (12) is provided with a back mounting plate, and the connection between the back mounting plate and the back cover (12) is provided with an end waterproof detection component (22).

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