Multifunctional DC circuit breaker

Abstract

The invention relates to the technical field of circuit breakers, and discloses a multifunctional direct-current circuit breaker which comprises a shell, leads arranged at the two ends of the shell, an anti-overload mechanism arranged on one side of the interior of the shell, an anti-short-circuit mechanism arranged at the bottom of the anti-overload mechanism and a tripping mechanism arranged on one side of the anti-short-circuit mechanism. The arc extinguishing mechanism is arranged on one side of the tripping mechanism; the short circuit prevention mechanism is used for preventing short circuit of the line, the overload prevention mechanism is used for preventing overload of the line, and the tripping mechanism is used for tripping when the short circuit prevention mechanism or the overload prevention mechanism is triggered to protect the circuit. Arc extinguishing efficiently adapts to a direct current scene, the arc extinguishing problem that the direct current does not have a natural zero crossing point is solved by assisting an arc striking electrode to actively pull and lengthen the arc and matching a funnel-shaped arc extinguishing grating and an accurate track alignment design, the arc is quickly segmented and extinguished, reignition is avoided, and the arc extinguishing device adapts to a high-voltage large-current scene.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and more particularly to a multifunctional DC circuit breaker. Background Technology

[0002] DC circuit breakers are core protection devices for DC circuits in photovoltaic inverters, energy storage systems, and other applications. However, existing technologies have many shortcomings, making it difficult to meet the application requirements of high efficiency, reliability, and low maintenance. Firstly, low arc extinguishing efficiency is a major pain point. DC current lacks a natural zero-crossing point, and existing technologies mostly rely on arc-extinguishing grids to passively receive the arc, failing to actively guide the arc root. This causes the arc root to remain on the surface of the stationary contacts for a long time, exacerbating contact erosion and oxidation, shortening component lifespan, and even causing arc reignition and incomplete breaking. While some designs add electromagnets and other driving components to assist arc extinguishing, this increases equipment size, cost, and potential failure points (such as electromagnet jamming). Secondly, the protection mechanisms suffer from poor coordination. Overload and short-circuit protection mechanisms often trigger asynchronously, the overload protection mechanism has a delayed thermal deformation response, and the short-circuit protection mechanism lacks sufficient electromagnetic triggering accuracy, easily missing the optimal breaking time and amplifying the impact of the fault. Furthermore, there is insufficient adaptability and economy. Existing equipment cannot withstand the high-frequency breaking operations of new energy scenarios, and frequent contact wear leads to short maintenance cycles and high costs. Therefore, to address the aforementioned pain points, active traction and arc lengthening are achieved through auxiliary arc-initiating electrodes and linkage drive components, while the arc-extinguishing efficiency is improved in conjunction with a "funnel-shaped" grid. The design of elastic contact pieces and contact shapes is optimized to reduce losses, ultimately adapting to high-frequency scenarios and balancing the reliability of disconnection with the economy of operation and maintenance. Summary of the Invention

[0003] In view of the problems of low arc extinguishing efficiency, asynchronous protection, and poor economic adaptability of existing DC circuit breakers, a multifunctional DC circuit breaker is proposed.

[0004] Its purpose is to solve the problems of inefficient arc extinguishing, asynchronous protection, and poor economic adaptability of existing DC circuit breakers, and to achieve efficient arc extinguishing, precise and coordinated protection, adapt to high-frequency scenarios and reduce operation and maintenance costs, so as to meet the reliable operation requirements of DC circuits.

[0005] The technical solution of the present invention is a multifunctional DC circuit breaker, including a housing, leads disposed at both ends of the housing, an overload protection mechanism disposed on one side inside the housing, a short circuit protection mechanism disposed at the bottom of the overload protection mechanism, a tripping mechanism disposed on one side of the short circuit protection mechanism, and an arc extinguishing mechanism disposed on one side of the tripping mechanism.

[0006] The short-circuit protection mechanism is used to prevent short circuits in the circuit, the overload protection mechanism is used to prevent overloads in the circuit, and the tripping mechanism is used to trip the circuit when the short-circuit protection mechanism or the overload protection mechanism is triggered, thereby protecting the circuit. The arc extinguishing mechanism is used to extinguish the electric arc generated when the tripping mechanism is triggered. The arc extinguishing mechanism includes an arc extinguishing cavity disposed inside the housing, an arc extinguishing grid disposed inside the arc extinguishing cavity, a moving contact disposed inside the housing, a baffle disposed inside the housing, and a stationary contact disposed on the baffle. The stationary contact is connected to one of the leads.

[0007] Furthermore, the tripping mechanism includes a toggle switch disposed on one side inside the housing, a fixed triangular plate disposed on one side of the toggle switch, a metal connecting piece disposed inside the fixed triangular plate for communicating with the moving contact, and a pull plate disposed between the metal connecting piece and the toggle switch.

[0008] Furthermore, the overload protection mechanism includes a limiting copper sheet disposed inside the housing, a combined piece disposed on one side of the bottom of the limiting copper sheet, a trigger component connected to the bottom of one end of the combined piece, the trigger component being connected to the short-circuit protection mechanism and the tripping mechanism respectively, and the bottom of the short-circuit protection mechanism being engaged with one end of the moving contact in the tripping mechanism.

[0009] Furthermore, the arc extinguishing mechanism also includes a connecting hole penetrating the baffle and the stationary contact, an elastic contact piece disposed within the connecting hole, the elastic contact piece being slidably connected to the side wall of the connecting hole, an auxiliary arc-initiating electrode disposed on the top of the elastic contact piece, a base plate disposed within the arc extinguishing cavity, an oblique groove and a vertical groove disposed on the base plate, a moving rod disposed on one side of the auxiliary arc-initiating electrode, a pushing rod disposed on one side of the moving contact, a pushing plate disposed on one side of the moving contact and the auxiliary arc-initiating electrode, a sliding hole disposed on one side of the pushing plate for the moving rod to move, a pushing hole disposed on the other side of the pushing plate for the pushing rod to move, and a limiting block disposed on one side of the middle of the pushing plate, the limiting block sliding within the vertical groove.

[0010] Furthermore, the elastic contact is a thin copper sheet with elasticity, and its bottom is bent towards the moving contact.

[0011] Furthermore, the width of the pushing hole is greater than the width of the sliding hole, and the diameter of the pushing rod is smaller than the diameter of the moving rod.

[0012] Furthermore, the end of the auxiliary arc-starting electrode is tapered, and a groove is provided on the moving rod on one side of the auxiliary arc-starting electrode to limit and slide in connection with the sliding hole, and the moving rod is limited and slidably connected in the inclined groove.

[0013] Furthermore, the moving contact is hook-shaped, with its bottom abutting against the surface of the stationary contact.

[0014] Furthermore, the center of the arc-extinguishing grid is configured as a "funnel shape", with its width gradually narrowing inward from the inlet.

[0015] Furthermore, the extension line of the translational trajectory of the auxiliary arc-initiating electrode end is aligned with the central inlet of the arc-extinguishing grid.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. Highly efficient arc extinguishing adapts to DC scenarios. By actively pulling and lengthening the arc through the auxiliary arc-initiating electrode, combined with the "funnel-shaped" arc-extinguishing grid and precise trajectory alignment design, it solves the problem of arc extinguishing when the DC current does not have a natural zero-crossing point, quickly divides and extinguishes the arc, avoids reignition, and is suitable for high-voltage and high-current scenarios.

[0017] 2. The auxiliary arc-starting electrode transfers the arc root, and the elastic contact plate ensures conductivity, reducing the erosion of the moving / static contacts; the hook-shaped moving contact and the pointed cone-shaped electrode accelerate the transfer of the arc root, extending the life of the components. It is especially suitable for high-frequency operation in photovoltaic and energy storage, reducing downtime maintenance costs and protecting components to reduce operation and maintenance costs.

[0018] 3. The structure is reliable and the protection is coordinated. Arc extinguishing relies on the mechanical linkage of the moving contact, which does not require additional drive and reduces the number of failure points. The overload protection (bimetallic strip) and short circuit protection mechanism accurately trigger the tripping, and the tripping sequence is reasonable, which improves the overall operation safety and disconnection reliability. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the circuit breaker of the present invention; Figure 2 This is a schematic diagram of the circuit breaker housing separation structure of the present invention; Figure 3 This is a schematic diagram of the overall internal structure of the circuit breaker of the present invention; Figure 4 This is a three-dimensional schematic diagram of the internal structure of the circuit breaker of the present invention; Figure 5 This is a schematic diagram of the overall structure of the arc-extinguishing mechanism of the present invention; Figure 6 This is a three-dimensional structural schematic diagram of the arc-extinguishing grid of the present invention; Figure 7 This is a schematic diagram of the mating structure of the arc extinguishing mechanism of the present invention; Figure 8 This is an exploded structural diagram of the arc-extinguishing mechanism of the present invention; Figure 9 This is a schematic diagram showing the connection structure between the push plate, the moving rod, and the push rod of the present invention.

[0020] In the picture: 1. Housing; 2. Overload protection mechanism; 21. Limiting copper sheet; 22. Combination piece; 23. Trigger assembly; 3. Arc extinguishing mechanism; 301. Arc extinguishing grid; 302. Moving contact; 303. Baffle; 304. Stationary contact; 305. Connecting hole; 306. Elastic contact piece; 307. Auxiliary arc-initiating electrode; 308. Base plate; 309. Angled groove; 310. Vertical groove; 311. Moving rod; 312. Push rod; 313. Push plate; 314. Sliding hole; 315. Push hole; 4. Trip mechanism; 41. Toggle switch; 42. Fixed triangular plate; 43. Metal connecting piece; 44. Pull plate; 5. Slot. Detailed Implementation

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] Example 1, referring to Figures 1-9 This is the first embodiment of the present invention, which provides a multifunctional DC circuit breaker, including a housing 1, leads disposed at both ends of the housing 1, an overload protection mechanism 2 disposed on one side inside the housing 1, a short-circuit protection mechanism disposed at the bottom of the overload protection mechanism 2, a tripping mechanism 4 disposed on one side of the short-circuit protection mechanism, and an arc extinguishing mechanism 3 disposed on one side of the tripping mechanism 4; the short-circuit protection mechanism is used to prevent short circuits in the circuit, the overload protection mechanism 2 is used to prevent overloads in the circuit, and the tripping mechanism 4 is used to trip when the short-circuit protection mechanism or the overload protection mechanism 2 is triggered, thereby protecting the circuit; the arc extinguishing mechanism 3 is used to extinguish the arc generated when the tripping mechanism 4 is triggered, and the arc extinguishing mechanism 3 includes an arc extinguishing cavity opened inside the housing 1, an arc extinguishing grid 301 fixedly connected in the arc extinguishing cavity, a moving contact 302 rotatably connected in the housing 1, a baffle 303 fixedly connected in the housing 1, and a stationary contact 304 abutting against the baffle 303, the stationary contact 304 being connected to one of the leads.

[0023] Specifically, a DC circuit breaker is a specialized protection and control switching device for DC circuit systems. Its core function is to reliably connect / disconnect DC current during normal circuit operation and to quickly interrupt fault current in the event of overload, short circuit, or other faults, preventing equipment damage or safety accidents (such as fire or insulation breakdown). Compared to AC circuit breakers, the core technical challenge of DC circuit breakers lies in the fact that DC current has no natural zero-crossing point, making arc extinguishing more difficult. Therefore, their structural design and arc extinguishing mechanisms differ significantly. When an overload or short circuit occurs in the circuit system, the overload protection mechanism 2 or the short circuit protection mechanism triggers the tripping mechanism 4 for tripping protection. During the tripping process, the arc extinguishing mechanism 3 extinguishes the arc generated during the tripping. When the tripping mechanism 4 of the moving contact 302 is driven to rotate, the moving contact 302 and the stationary contact 304 separate, and an electric arc is generated between them. As the moving contact 302 rotates, the electric arc moves along the stationary contact 304 and into the arc-extinguishing cavity. It is divided into several short arcs by the arc-extinguishing grid 301, and finally the electric arc disappears within the arc-extinguishing grid 301, thus achieving the arc-extinguishing effect. The arc-extinguishing mechanism 3 can actively "drag" the electric arc generated during the tripping process, allowing its arc root to enter the grid area. This can protect the stationary contact 304 and accelerate the arc-extinguishing process. It is suitable for high-frequency operation scenarios such as photovoltaic inverters and energy storage systems, ensuring reliable tripping while significantly reducing operation and maintenance costs. At the same time, it integrates four core protection functions: overload protection, short-circuit protection, tripping, and arc-extinguishing energy dissipation, achieving a multi-functional protection effect for DC circuit breakers.

[0024] Reference Figures 2-3 The tripping mechanism 4 includes a toggle switch 41 rotatably connected to one side of the housing 1, a fixed triangular plate 42 fixedly connected to one side of the toggle switch 41, a metal connecting piece 43 for communicating with the moving contact 302 inside the fixed triangular plate 42, and a pull plate 44 hinged between the metal connecting piece 43 and the toggle switch 41. The pull plate 44 is used to drive the toggle switch 41 to reset.

[0025] Specifically, the tripping mechanism 4 is existing technology. It trips by being triggered by the overload protection mechanism 2 and the short-circuit protection mechanism, thus achieving circuit breaking. Under normal operating conditions, the toggle switch 41 is in the toggle position, and the leads at both ends, the overload protection mechanism 2, the short-circuit protection mechanism, and the tripping mechanism 4 are all connected, making the entire circuit continuous. When a short circuit or overload occurs, the short-circuit protection mechanism or the overload protection mechanism 2 activates, causing the triggering mechanism to rotate the moving contact 302 to break the circuit. This is only a brief explanation of the working process; the overload protection mechanism 2, the short-circuit protection mechanism, and the triggering mechanism are all existing technologies and will not be described in detail.

[0026] Reference Figure 3The overload protection mechanism 2 includes a limiting copper plate 21 fixed inside the housing 1, and a combination piece 22 fixedly connected to one side of the bottom of the limiting copper plate 21. A trigger component 23 (existing technology, not described in detail) is connected to the bottom of one end of the combination piece 22. The trigger component 23 is connected to the short circuit protection mechanism and the tripping mechanism 4 respectively, and the bottom of the short circuit protection mechanism is engaged with one end of the moving contact 302 in the tripping mechanism 4.

[0027] Specifically, the overload protection mechanism 2 is triggered by the combination plate 22 to trip the circuit breaker mechanism 4. The combination plate 22 is composed of two metal plates with different thermal conductivity. When an overload occurs, a large amount of heat will be generated, causing the combination plate 22 to bend and deform, thereby triggering the circuit breaker mechanism 4 to trip.

[0028] Reference Figures 4-9 The arc-extinguishing mechanism 3 also includes a connecting hole 305 penetrating through the baffle 303 and the stationary contact 304, an elastic contact piece 306 slidably connected in the connecting hole 305, the elastic contact piece 306 slidingly connected to the side wall of the connecting hole 305, an auxiliary arc-initiating electrode 307 fixedly connected to the top of the elastic contact piece 306, a base plate 308 fixed in the arc-extinguishing cavity, an oblique groove 309 and a vertical groove 310 formed on the base plate 308, a movable rod 311 fixed to one side of the auxiliary arc-initiating electrode 307, and a moving contact 302 fixed to one side. The push rod 312, the push plate 313 set on one side of the moving contact 302 and the auxiliary arc-starting electrode 307, the sliding hole 314 opened on one side of the push plate 313 for the moving rod 311 to move, the push hole 315 opened on the other side of the push plate 313 for the pushing rod 312 to move, and the limiting block fixed on one side of the middle part of the push plate 313, the limiting block slides in the vertical groove 310. The moving rod 311, the push rod 312, the push plate 313, etc. can all be made of insulating material to avoid affecting the arc extinguishing process.

[0029] Specifically, when the arc-extinguishing mechanism 3 is working, when the moving contact 302 rotates, it separates from the stationary contact 304, and an electric arc is generated between them. The electric arc moves as the moving contact 302 rotates. When the moving contact 302 rotates, the push rod 312 at its bottom rotates within the push hole 315. Since the limiting block on one side of the push plate 313 slides within the vertical groove 310, when the push rod 312 rotates within the push hole 315, it causes the push plate 313 to move along the direction of the vertical groove 310. When the push plate 313 moves upward, it will simultaneously drive the moving rod 311 to move upward. Since the moving rod 311 is simultaneously limited in the inclined groove 309 and the sliding hole 314, the auxiliary arc-initiating electrode 307 moves along the inclined groove 309. When the auxiliary arc-initiating electrode 307 brings the arc root close to the arc-extinguishing grid 301, it simultaneously lengthens the arc. When the arc is closest to the extinguishing grid, it can be stretched into a thinner and longer shape, which makes it easier for several grid plates to separate the thin arc and accelerate the arc extinguishing process. When the auxiliary arc-starting electrode 307 moves, the elastic contact 306 also moves. In the initial stage of movement, the elastic contact is always connected to the stationary contact 304, which facilitates the arc to move to the auxiliary arc-starting electrode 307. When the auxiliary arc-starting electrode 307 moves to its final position, the elastic contact 306 disengages from the stationary contact 304, cuts off the auxiliary circuit, avoids the auxiliary arc-starting electrode 307 from being energized for a long time, eliminates the risk of leakage, energy loss or component mis-triggering, eliminates secondary arcs, and prevents the generation of new arcs due to residual potential difference between the auxiliary electrode and the stationary contact 304, ensuring complete arc extinguishing.

[0030] On the one hand, the auxiliary arc-initiating electrode 307 actively "pulls" the arc root by moving obliquely, preventing the arc from lingering at the separation point of the moving / stationary contact 304 and forcibly guiding the arc root to the arc-extinguishing grid 301. On the other hand, the linkage structure (the push plate 313 drives the moving rod 311) actively lengthens the arc while initiating it, changing the arc from a "short and thick" shape to a "slender and long" shape. This not only increases the arc resistance (reducing the current density) but also allows for a larger contact area between the arc and the arc-extinguishing grid 301, making the arc enter more smoothly. In traditional arc-extinguishing structures, the arc root (the part with the highest temperature and most concentrated energy) tends to adhere to the surface of the stationary contact 304 for a long time, causing the stationary contact 304 to be ablated by high temperature and the contact surface to be oxidized, thereby reducing the conductivity of the contact and shortening the replacement cycle. By setting an auxiliary arc-starting electrode 307, the high conductivity and high temperature resistance of the electrode are used to "accept" the arc root, transferring the arc root from the stationary contact 304 to itself. At the same time, the sliding design of the elastic contact piece 306 ensures that the auxiliary arc-starting electrode 307 always maintains a reliable electrical connection with the stationary contact 304 when it moves, avoiding temporary circuit interruption or poor contact caused by arc ignition. This significantly reduces the amount of ablation of the stationary contact 304 and the moving contact 302, extends the life of the contacts, and indirectly reduces the operation and maintenance replacement costs of the equipment (especially suitable for high-frequency disconnection scenarios such as photovoltaics and energy storage, reducing the number of downtime maintenance).

[0031] In addition, the arc extinguishing action relies entirely on the rotational driving force of the moving contact 302, eliminating the need for additional electromagnets, motors, or other driving components. The absence of electronic components or additional power sources reduces potential points of failure due to "drive failure" (such as electromagnet jamming or motor power failure). Furthermore, it is adaptable to challenging arc extinguishing scenarios in DC circuits, expanding its application range. The core challenge in DC circuit arc extinguishing is the lack of a natural zero-crossing point for the current, making the arc more difficult to extinguish (AC arcs can be extinguished naturally by using a zero-crossing point). This mechanism's design specifically addresses this issue. The "traction and elongation" action of the auxiliary arc-initiating electrode 307 allows the arc to quickly enter the arc-extinguishing grid 301 and be completely extinguished, preventing repeated reignition of the arc near the contact, reducing secondary arc hazards, and improving equipment operational safety.

[0032] Example 2, refer to Figure 5 and Figures 7-9 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the elastic contact 306 is a thin copper sheet with elasticity, and its bottom is bent toward the moving contact 302.

[0033] Specifically, the thin copper sheet combines high conductivity and elasticity to ensure reliable conduction between the auxiliary arc-initiating electrode 307 and the stationary contact 304 when the auxiliary arc-initiating electrode 307 moves, ensuring smooth transfer of the arc root. The bottom bends towards the moving contact 302, providing a larger deformation space for the contact piece (to accommodate the movement of the auxiliary arc-initiating electrode 307) and facilitating the connection of the arc. The elastic properties ensure that the elastic contact piece 306 always fits tightly against the wall of the connection hole 305, reducing contact resistance and preventing additional arcs from being generated due to poor contact during the transfer process.

[0034] Reference Figure 9 The width of the pushing hole 315 is greater than the width of the sliding hole 314, and the diameter of the pushing rod 312 is smaller than the diameter of the moving rod 311.

[0035] Specifically, when the push rod 312 rotates within the push hole 315, due to the smaller size of the push rod 312 and the larger size of the push hole 315, the push plate 313 does not move during the initial rotation of the moving contact 302. That is, during the initial opening phase, the auxiliary electrode does not move, while the moving contact 302 rotates, allowing the arc to be quickly introduced onto the auxiliary arc-initiating electrode 307. During the initial opening phase, the auxiliary electrode remains stationary, its position directly opposite the separation point of the moving contact 302. The electric field is concentrated and stable, enabling it to quickly "capture" the arc generated when the moving contact 302 separates from the stationary contact 304, allowing the arc root to preferentially adhere to the auxiliary electrode (rather than remaining on the stationary contact 304). This avoids arc drift and arc root rebound that could burn the stationary contact 304 due to initial auxiliary electrode movement, reducing stationary contact 304 wear from the source, ensuring the arc root's preferential and stable transfer, protecting the stationary contact 304, achieving a reasonable timing sequence of "arc initiation first, then extension," and improving arc extinguishing reliability.

[0036] Reference Figures 8-9The end of the auxiliary arc-starting electrode 307 is tapered. A groove 5 is provided on the moving rod 311 on one side of the auxiliary arc-starting electrode 307 and is limited and slidably connected to the sliding hole 314. The moving rod 311 is limited and slidably connected in the inclined groove 309.

[0037] Specifically, the high electric field intensity at the tip allows for rapid attraction of the arc root using the "tip discharge effect," ensuring that the arc preferentially attaches to the auxiliary arc-initiating electrode 307 during the initial opening phase. This accelerates the transfer of the arc root from the stationary contact 304 to the auxiliary electrode, reducing the erosion of the stationary contact 304. The dual limiting of the slot 5 and the oblique slot 309 ensures accurate trajectory.

[0038] Reference Figures 7-8 The moving contact 302 is hook-shaped, and its bottom abuts against the surface of the stationary contact 304.

[0039] Specifically, the hook shape facilitates the smooth and rapid transfer of the electric arc.

[0040] The middle part of the arc-extinguishing grid 301 is set in a "funnel shape", and its width gradually narrows inward from the inlet.

[0041] Specifically, the funnel-shaped design (wide entrance, inward contraction) in the middle of the arc extinguishing grid 301 expands the arc capture range through the wide entrance to prevent escape, and the contraction section forces the arc to converge and be oriented to ensure that it is accurately divided by the grid. At the same time, the spatial constraint enhances cooling and deionization to accelerate arc extinguishing, and forms a one-way channel to prevent arc rebound and reignition. Overall, it greatly improves the arc extinguishing efficiency and reliability, and is especially suitable for the high-efficiency arc extinguishing requirements in high-voltage and high-current scenarios.

[0042] Reference Figures 5-7 The extension line of the translational trajectory of the end of the auxiliary arc-initiating electrode 307 is aligned with the center inlet of the arc-extinguishing grid 301.

[0043] Specifically, this design precisely guides the electric arc into the arc-extinguishing grid 301, preventing it from deviating or drifting away. It fits the central inlet of the arc-extinguishing grid 301, eliminating the need for arc direction adjustment and accelerating arc extinguishing. The remaining structure is the same as in Embodiment 1.

[0044] Based on embodiments 1-2, the working principle of the present invention is as follows: When the circuit is normal, the toggle switch 41 of the tripping mechanism 4 is in the conducting state, and the current forms a circuit through the lead wire, the overload protection mechanism 2, the short circuit protection mechanism, the tripping mechanism 4, the moving contact 302, and the stationary contact 304; In case of fault, overload will cause the bimetallic composite plate 22 of the overload protection mechanism 2 to bend due to heat, and short circuit will trigger the short circuit protection mechanism. Both of these will drive the tripping mechanism 4 to operate, causing the moving contact 302 to rotate around the axis and separate from the stationary contact 304. When the circuit breaker is opened, the arc extinguishing mechanism 3 is activated. The moving contact 302 rotates, causing the push rod 312 to move within the push hole 315. Due to the constraint of the limit block, the push plate 313 moves upward along the vertical groove 310, driving the moving rod 311 and the auxiliary arc-initiating electrode 307 to move along the inclined groove 309. Initially, the elastic contact 306 remains in contact with the stationary contact 304. The auxiliary arc-initiating electrode 307 (with a pointed conical end) captures the arc root by means of the tip effect, preventing the stationary contact 304 from being burned. Subsequently, the auxiliary electrode elongates the arc, and its translational trajectory is aligned with the center entrance of the arc extinguishing grid 301. The arc is introduced into the "funnel-shaped" grid, and after being divided into short arcs by the grid, it is quickly extinguished. After the auxiliary electrode is in place, the elastic contact 306 disengages from the stationary contact 304 to cut off the auxiliary circuit, eliminating secondary arcs. The whole system achieves efficient arc extinguishing and component protection, making it suitable for high-difficulty DC arc extinguishing scenarios.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multifunctional DC circuit breaker, comprising a housing (1), leads disposed at both ends of the housing (1), an overload protection mechanism (2) disposed on one side inside the housing (1), a short-circuit protection mechanism disposed at the bottom of the overload protection mechanism (2), and a tripping mechanism (4) disposed on one side of the short-circuit protection mechanism, characterized in that, It also includes an arc extinguishing mechanism (3) located on one side of the tripping mechanism (4); The short-circuit protection mechanism is used to prevent short circuits in the circuit, the overload protection mechanism (2) is used to prevent overloads in the circuit, and the tripping mechanism (4) is used to trip the circuit when the short-circuit protection mechanism or the overload protection mechanism (2) is triggered, thus protecting the circuit. The arc extinguishing mechanism (3) is used to extinguish the electric arc generated when the tripping mechanism (4) is triggered. The arc extinguishing mechanism (3) includes an arc extinguishing cavity disposed inside the housing (1), an arc extinguishing grid (301) disposed inside the arc extinguishing cavity, a moving contact (302) disposed inside the housing (1), a baffle (303) disposed inside the housing (1), and a stationary contact (304) disposed on the baffle (303). The stationary contact (304) is connected to one of the leads.

2. The multifunctional DC circuit breaker according to claim 1, characterized in that The tripping mechanism (4) includes a toggle switch (41) disposed on one side inside the housing (1), a fixed triangular plate (42) disposed on one side of the toggle switch (41), a metal connecting piece (43) disposed inside the fixed triangular plate (42) for communicating with the moving contact (302), and a pull plate (44) disposed between the metal connecting piece (43) and the toggle switch (41).

3. The multifunctional DC circuit breaker according to claim 2, characterized in that The overload protection mechanism (2) includes a limiting copper plate (21) disposed inside the housing (1), a combination plate (22) disposed on one side of the bottom of the limiting copper plate (21), a trigger component (23) connected to the bottom of one end of the combination plate (22), the trigger component (23) being connected to the short circuit protection mechanism and the tripping mechanism (4) respectively, and the bottom of the short circuit protection mechanism being engaged with one end of the moving contact (302) inside the tripping mechanism (4).

4. The multifunctional DC circuit breaker according to claim 1, characterized in that The arc-extinguishing mechanism (3) further includes a connecting hole (305) penetrating through the baffle (303) and the stationary contact (304), an elastic contact piece (306) disposed in the connecting hole (305), the elastic contact piece (306) being slidably connected to the side wall of the connecting hole (305), an auxiliary arc-starting electrode (307) disposed on the top of the elastic contact piece (306), a base plate (308) disposed in the arc-extinguishing cavity, an oblique groove (309) and a vertical groove (310) disposed on the base plate (308), and an auxiliary arc-starting electrode (307). A movable rod (311) on one side, a push rod (312) on one side of the movable contact (302), a push plate (313) on one side of the movable contact (302) and the auxiliary arc-starting electrode (307), a sliding hole (314) on one side of the push plate (313) for the movable rod (311) to move, a push hole (315) on the other side of the push plate (313) for the push rod (312) to move, and a limiting block on one side of the middle part of the push plate (313), the limiting block sliding in the vertical groove (310).

5. The multifunctional DC circuit breaker according to claim 4, characterized in that The elastic contact (306) is a thin copper sheet with elasticity, and its bottom is bent toward the moving contact (302).

6. The multifunctional DC circuit breaker according to claim 4, characterized in that The width of the pushing hole (315) is greater than the width of the sliding hole (314), and the diameter of the pushing rod (312) is smaller than the diameter of the moving rod (311).

7. The multifunctional DC circuit breaker according to claim 4, characterized in that The end of the auxiliary arc-starting electrode (307) is tapered. A groove (5) is provided on the moving rod (311) on one side of the auxiliary arc-starting electrode (307) and is limited and slidably connected to the sliding hole (314). The moving rod (311) is limited and slidably connected in the inclined groove (309).

8. The multifunctional DC circuit breaker according to claim 1, characterized in that The moving contact (302) is hook-shaped, and its bottom abuts against the surface of the stationary contact (304).

9. The multifunctional DC circuit breaker according to claim 1, characterized in that The arc-extinguishing grid (301) is configured in a funnel shape in the middle, with its width gradually narrowing inward from the inlet.

10. The multifunctional DC circuit breaker according to claim 7, characterized in that, The extension line of the translational trajectory of the end of the auxiliary arc-initiating electrode (307) is aligned with the central entrance of the arc-extinguishing grid (301).

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