circuit breaker

Abstract

The utility model discloses a circuit breaker relates to electrical protection device technical field, wherein, the circuit breaker static contact forms the bending extension section, and the bending extension section has the overhanging height in the vertical direction, and the static contact point is arranged on the bending extension section, and the electric repulsion between static contact point and dynamic contact point is strengthened, and the dynamic static contact point is accelerated and breaks, and the arc time is shortened to reduce the ablation and energy loss of arc to the contact, the gas cover forms the arc channel, and the gas cover and the bending extension section cooperate and form the sealed chamber to compress the space of arc chamber, and the application of arc extinguishing grid group can further limit short -circuit current and reduce breaking energy, and utilize the gas pressure -maintaining effect and extinguish arc quickly and cool.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, and in particular to a circuit breaker. Background Technology

[0002] Circuit breakers (molded case circuit breakers or frame circuit breakers) are the most important power distribution equipment in low-voltage power distribution systems. The contacts and arc-extinguishing system are crucial components of circuit breakers, directly affecting their electrical life and breaking capacity. Taking frame circuit breakers as an example, they are used in high-voltage DC scenarios, such as energy storage devices, where DC voltages typically reach thousands of volts. When the moving and stationary contacts of a frame circuit breaker break, an electric arc is generated due to gas discharge. Currently, the arc is mainly extinguished by multiple arc-isolating grids, which, driven by the magnetic field and fluid effect within the arc-extinguishing chamber, are divided into multiple short arcs. The metal arc-isolating grids enhance the deionization effect of the arc, thus extinguishing it.

[0003] The electric arc generated by the current needs to be extinguished quickly to prevent equipment damage or fire. However, in existing solutions, the arc enters the arc-extinguishing chamber slowly, resulting in a slow arc-extinguishing speed in the arc-extinguishing chamber, which affects the service life of the circuit breaker contacts and the circuit breaking time. Utility Model Content

[0004] The main purpose of this invention is to propose a circuit breaker that improves the existing arc-extinguishing chamber structure, enabling it to achieve better arc-extinguishing performance within a limited structural space.

[0005] To achieve the above objectives, the circuit breaker proposed in this utility model includes:

[0006] A stationary contact assembly includes a contact substrate and a stationary contact, wherein the end of the contact substrate is provided with a bent extension section that bends toward the other end; the stationary contact is disposed on the mounting surface of the bent extension section.

[0007] An arc-extinguishing chamber assembly includes an arc-extinguishing chamber, an arc-extinguishing grid assembly disposed within the arc-extinguishing chamber, and a gas-generating hood. The gas-generating hood includes an arc-extinguishing baffle and two arc-extinguishing sidewalls disposed opposite to and abutting against the side edge of the bent extension section. The bent extension section, the arc-extinguishing baffle, and the arc-extinguishing sidewalls together enclose and define a sealed cavity.

[0008] In one embodiment, the stationary contact assembly further includes an arc-initiating plate, the arc-initiating plate and the stationary contact being sequentially disposed on the mounting surface along the extending direction of the bent extension section, and the end of the arc-initiating plate extending beyond the free end of the bent extension section; the arc-extinguishing baffle is in contact with the free end of the arc-initiating plate, and the bent extension section, the arc-initiating plate, the arc-extinguishing baffle and the arc-extinguishing sidewall together enclose and define the sealed cavity.

[0009] In one embodiment, the width of the bent extension is smaller than the width of the contact substrate.

[0010] In one embodiment, the width of the arc-inducing plate is greater than or equal to the width of the stationary contact.

[0011] In one embodiment, the length of the arc-inducing plate in the bent extension section is less than or equal to the length of the stationary contact.

[0012] In one embodiment, the length of the arc-initiating plate extending beyond the bent extension is less than or equal to the length of the arc-initiating plate in the bent extension.

[0013] In one embodiment, the contact base plate includes a wiring horizontal plate, a connecting vertical plate, and a mounting horizontal plate, wherein the bent extension section bends from the mounting horizontal plate toward the connecting vertical plate; the contact base plate is also provided with a through slot, which extends from the connection between the mounting horizontal plate and the bent extension section to the connecting vertical plate.

[0014] In one embodiment, the through slot extends to the connection point between the connecting vertical plate and the wiring horizontal plate.

[0015] In one embodiment, the bent extension is formed by partially separating and bending the contact substrate in the opposite direction, and the through slot is formed on the connecting vertical plate and the mounting horizontal plate at the original separation position.

[0016] In one embodiment, the length of the through slot on the connecting vertical plate is L, where 5mm ≤ L ≤ 15mm.

[0017] In one embodiment, the arc-extinguishing grid assembly is located above the arc-initiating plate, and the arc-extinguishing grid assembly includes a plurality of arc-extinguishing plates stacked vertically along the arc-extinguishing chamber, with an arc-extinguishing gap formed between the arc-initiating plate and the nearest arc-extinguishing plate.

[0018] In one embodiment, the wiring cross plate is further provided with a wiring port and mounting holes for fixing the gas generating hood.

[0019] In one embodiment, the surface of the wiring crossbar also has anti-slip texture.

[0020] The technical solution of this utility model uses a bent extension section formed by the stationary contact, which has a suspended height in the vertical direction. The stationary contact is set on the bent extension section, which enhances the electric repulsion between the stationary and moving contacts, accelerates the breaking of the moving and stationary contacts, and shortens the arcing time, thereby reducing the erosion of the contacts and energy loss caused by the arc. Furthermore, the gas generating hood and the bent extension section work together to form a sealed cavity in the arc extinguishing chamber, which can compress the space of the arc extinguishing chamber and use the gas pressure holding effect to quickly cool and extinguish the arc, reducing energy waste and pollution caused by prolonged arcing. Moreover, the application of the high-impedance arc extinguishing grid can limit the short-circuit current and reduce the breaking energy, reducing carbon emissions during circuit faults, thereby reducing the arc duration. The stationary contact assembly and the arc extinguishing chamber assembly adopt a modular design, which indirectly reduces energy consumption and material loss. Thus, the circuit breaker can improve the arc extinguishing efficiency and save material loss, which is highly related to the ESG green concept. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 A cross-sectional structural schematic diagram of an embodiment of the circuit breaker provided by this utility model;

[0023] Figure 2 A cross-sectional structural schematic diagram of an embodiment of the stationary contact assembly and the arc-extinguishing chamber assembly;

[0024] Figure 3 This is a schematic diagram of one embodiment of the gas generation shroud and contact substrate;

[0025] Figure 4 for Figure 3 Top view in the middle;

[0026] Figure 5 This is a schematic diagram of a structure of an embodiment of a stationary contact assembly.

[0027] Explanation of icon numbers:

[0028] 10. Stationary contact assembly;

[0029] 11. Contact base plate; 11a. Wiring horizontal plate; 11a1. Wiring port; 11a2. Mounting hole; 11a3. Anti-slip texture; 11b. Connecting vertical plate; 11c. Mounting horizontal plate; 11d. Bending extension section; 11d1. Mounting surface; 11e. Through slot;

[0030] 12. Static contact;

[0031] 13. Arc-starting plate;

[0032] 20. Arc-extinguishing chamber assembly; 20a. Arc-extinguishing chamber;

[0033] 30. Gas generating hood; 31. Arc extinguishing baffle; 31a. Arc exit port; 32. Arc extinguishing sidewall; 32a. Arc ignition channel; 32b. Sealed cavity;

[0034] 40. Arc-extinguishing grid assembly; 41. Partition plate; 42. Arc-extinguishing plate; 43. Arc-extinguishing gap;

[0035] 50. Moving contact.

[0036] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0038] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0039] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0040] Circuit breakers (molded case circuit breakers or frame circuit breakers) are the most important power distribution equipment in low-voltage power distribution systems. The contacts and arc extinguishing system are important components of circuit breakers, directly affecting their electrical life and breaking capacity.

[0041] Taking a frame circuit breaker as an example, frame circuit breakers are used in high-voltage DC scenarios, such as energy storage devices, where DC voltage typically reaches thousands of volts. When the moving and stationary contacts of the frame circuit breaker break, an electric arc is generated due to gas discharge. Currently, the arc is mainly extinguished by multiple arc-isolating grids, which are separated into multiple short arcs by the magnetic field and fluid effect in the arc-extinguishing chamber. The arc is then extinguished by the metal arc-isolating grids enhancing the deionization effect of the arc.

[0042] The electric arc generated by the current needs to be extinguished quickly to prevent equipment damage or fire. However, in existing solutions, the arc enters the arc-extinguishing chamber slowly, resulting in a slow arc-extinguishing speed in the arc-extinguishing chamber, which affects the service life of the circuit breaker contacts and the circuit breaking time.

[0043] This utility model proposes a circuit breaker that raises the stationary contact through a bent extension section. On the one hand, the raised bent extension section generates a stronger electric repulsive force when the moving and stationary contacts are short-circuited, which helps to quickly open the moving and stationary contacts. On the other hand, it makes the internal space of the stationary contact assembly, the arc-extinguishing chamber, and the gas-generating hood more sealed. The sealed space can better maintain gas pressure, which is beneficial for arc extinguishing.

[0044] Please see Figures 1 to 5 In one embodiment of the present invention, the circuit breaker includes a stationary contact assembly 10 and an arc-extinguishing chamber assembly 20. The stationary contact assembly 10 includes a contact base plate 11 and a stationary contact 12. The end of the contact base plate 11 is provided with a bent extension section 11d that bends toward the other end. The stationary contact 12 is disposed on the mounting surface 11d1 of the bent extension section 11d that is opposite to the mounting cross plate 11c. The mounting surface 11d1 and the mounting cross plate 11c have a suspension height in the vertical direction (the bending height of the bent extension section 11d).

[0045] Reference Figure 1 and Figure 2 The arc-extinguishing chamber assembly 20 includes an arc-extinguishing chamber 20a, an arc-extinguishing grid assembly 40 disposed within the arc-extinguishing chamber 20a, and a gas-generating hood 30. The gas-generating hood 30 includes an arc-extinguishing baffle 31 and two arc-extinguishing sidewalls 32 that are disposed opposite to and abut against the side edge of the bent extension section 11d. The bent extension section 11d, the arc-extinguishing baffle 31, and the arc-extinguishing sidewalls 32 together enclose and define a sealed cavity 32b.

[0046] It should be noted that the horizontal extension (left and right direction) is only used to explain the relative positional relationship between the wiring horizontal plate 11a and the connecting vertical plate 11b. It does not necessarily require the wiring horizontal plate 11a to be horizontal in the installed state, nor does it require the wiring horizontal plate 11a to be parallel to the mounting horizontal plate 11c. Similarly, the vertically bent connecting vertical plate 11b does not necessarily have to be perpendicular to the horizontal plane. As long as it is roughly in the up and down direction relative to the mounting horizontal plate 11c in its own extension direction, it is irrelevant whether the connecting vertical plate 11b itself is vertical or not.

[0047] Reference Figure 5 In one embodiment, the contact substrate 11 includes a horizontally extending wiring horizontal plate 11a, a vertically bent connecting vertical plate 11b, and a horizontally extending mounting horizontal plate 11c. The end of the mounting horizontal plate 11c is provided with a bent extension section 11d that bends toward the wiring horizontal plate 11a. The stationary contact 12 is provided on the mounting surface 11d1 of the bent extension section 11d that is away from the mounting horizontal plate 11c. The mounting surface 11d1 and the mounting horizontal plate 11c have a suspension height in the vertical direction.

[0048] Reference Figures 1 to 3 Furthermore, the arc-extinguishing baffle 31 is provided with an arc outlet 31a that connects to the arc-extinguishing chamber 20a, and there is also an arc-initiating channel 32a between the two arc-extinguishing sidewalls 32 that faces the arc-extinguishing grid group 40. The moving contact 50 can abut against or disengage from the stationary contact 12 within the arc-initiating channel 32a.

[0049] Understandably, a circuit breaker typically includes multiple stationary contact assemblies 10, and the moving contact 50 system cooperates with the stationary contact assemblies 10 within the arc-extinguishing chamber 20a. The following description uses one of the stationary contact assemblies 10 and the arc-extinguishing chamber assembly 20 as an example.

[0050] The main function of the arc-initiating channel 32a is to guide the electric arc into the arc-extinguishing chamber 20a, accelerating arc transfer through magnetic fields or structural design, thereby improving arc-extinguishing efficiency. Within the channel, the arc is confined by the sidewalls of the gas-generating shroud 30, preventing it from spreading to either side, thus concentrating arc energy and improving arc-extinguishing efficiency. Simultaneously, the channel's airtightness helps maintain a local high-pressure environment, further propelling the arc into the arc-extinguishing grid assembly 40 region.

[0051] During short-circuit breaking, the gas-generating material (such as aromatic insulators), i.e., the arc-extinguishing sidewall, decomposes under the high temperature of the electric arc, generating high-pressure gas. The arc-ignition channel 32a directs these gases towards the arc-extinguishing grid assembly 40 area, reducing the arc temperature and disrupting the arc's conductivity through physical cooling and blowing. The arc exit 31a is located on the arc-extinguishing baffle 31 and connects to the arc-extinguishing chamber 20a. During arc extinguishing, the arc exit 31a discharges the arc-extinguishing medium (such as high-pressure gas or ionized substances) to cool and extinguish the arc, achieved through gas blowing or pressure release.

[0052] The contact base plate 11 is Z-shaped, and the bent extension section 11d is L-shaped and bends towards the connecting vertical plate 11b of the contact base plate 11. The mounting surface 11d1 does not include the bent part of the bent extension section 11d. The mounting surface 11d1 is provided with a stationary contact 12. The moving contact 50 can abut against or disengage from the stationary contact 12 in the arc ignition channel 32a. The stationary contact 12 contacts or disconnects from the moving contact to realize the circuit breaker's connection or disconnection of the conductive system.

[0053] In this embodiment, the wiring horizontal plate 11a is higher than the mounting horizontal plate 11c; in other embodiments, the wiring horizontal plate 11a may be lower than the mounting horizontal plate 11c; or the wiring horizontal plate 11a may be flush with the mounting horizontal plate 11c.

[0054] Because there is a vertical gap between the mounting surface 11d1 and the mounting plate 11c, and the bent extension 11d and the mounting plate 11c have a U-shaped structure, the current directions on the bent extension 11d and the mounting plate 11c are opposite. According to the Lorentz force, the current will be subjected to a force in the magnetic field. When the short-circuit current passes through the parallel conductors (moving and stationary contacts), the magnetic fields generated by the reverse currents interact, resulting in a repulsive force (Holm force) between the contacts. The bending structure can increase the equivalent area of ​​the current path, thereby enhancing the repulsive force, accelerating the contact separation, thus shortening the arc duration and reducing the damage of the arc to the contacts.

[0055] Reference Figures 1 to 3 The gas generating hood 30 is set inside the arc extinguishing chamber 20a and forms an arc ignition channel 32a. The bent extension section 11d can also guide the electric arc from the arc ignition channel 32a through the arc extinguishing grid group 40 structure to quickly cool the electric arc. The arc extinguishing gap 43 in the arc extinguishing grid group 40 divides the electric arc into multiple segments, thereby significantly improving the arc extinguishing effect.

[0056] In addition, below the arc-ignition channel 32a, the bent extension section 11d, the arc-extinguishing baffle 31, and the arc-extinguishing sidewall 32 together enclose and define a sealed cavity 32b, which can compress the space of the arc-extinguishing chamber 20a to enhance the pressure holding and gas blowing effect. When the electric arc is generated, the surrounding materials (such as gas-generating materials) are heated and decomposed to produce gas. The high-pressure gas can blow the electric arc, cool it and lengthen it. Because of the presence of the sealed cavity 32b, the space of the arc-extinguishing chamber 20a is compressed, and the generated gas pressure will be higher, thus more effectively blowing the electric arc into the arc-extinguishing grid group 40. Moreover, the high-pressure gas not only blows the arc, but also carries the arc energy to the arc-extinguishing grid group 40. The arc is divided into multiple short arcs by the arc-extinguishing grid group 40, increasing the arc pressure drop and accelerating the arc extinction.

[0057] It should be noted that the upper part of the sealed cavity 32b is formed by the arc-starting plate 13 and the bent extension section 12 in conjunction with the gas generating hood 30. The gas generating hood 30 is a single piece. Therefore, due to the limitations of the manufacturing process, a certain error (such as 0.2mm-1mm) is allowed between the arc-starting plate 13, the bent extension section 12 and the gas generating hood 30, which can also compress the space of the arc-extinguishing chamber 20a.

[0058] The technical solution of this utility model is that the bent extension section 11d and the mounting plate 11c form a U-shaped structure. The current directions on the bent extension section 11d and the mounting plate 11c are opposite. The arc is guided by a magnetic field, and the contact repulsion accelerates separation, thereby shortening the arc duration and reducing the damage of the arc to the contacts. The arc is extinguished by lengthening the arc. Furthermore, the bent extension section 11d can also guide the arc to the arc extinguishing grid group 40 structure in conjunction with the arc ignition channel 32a, dividing it into multiple short arcs for extinguishing. In addition, the gas generating hood 30 seals the bent extension section 11d to form a sealed cavity 32b and an arc ignition channel 32a, compressing the space of the arc extinguishing chamber 20a to enhance the pressure holding and air blowing effect, achieving rapid arc extinguishing. Thus, this solution achieves superior arc extinguishing performance within a limited structural space by lengthening the arc, using a magnetic field to drive the arc, dividing it into multiple short arcs, and cooling multiple arc extinguishing methods.

[0059] Furthermore, to enhance the arc guiding effect, enabling the arc to transfer more quickly from the contact to the arc-extinguishing chamber 20a, reducing contact erosion, and allowing the contacts to repel more quickly, the stationary contact assembly 10 also includes an arc-initiating plate 13. The arc-initiating plate 13 and the stationary contact 12 are sequentially arranged on the mounting surface 11d1 along the extension direction of the bent extension section 11d, with the end of the arc-initiating plate 13 extending beyond the free end of the bent extension section 11d. The arc-extinguishing baffle 31 is in close contact with the free end of the arc-initiating plate 13. The bent extension section 11d, the arc-initiating plate 13, the arc-extinguishing baffle 31, and the arc-extinguishing sidewall 32 together enclose and define the sealed cavity 32b.

[0060] The arc-starting plate 13 is designed to optimize the magnetic field distribution through magnetic materials (such as ferromagnetic alloys). When a short-circuit current passes through, the arc current will be subjected to the Lorentz force in the magnetic field, which forces the arc to move rapidly toward the arc-extinguishing grid group 40, thereby preventing the arc from stagnating on the contact surface and reducing contact erosion.

[0061] When the stationary contact 12 breaks, the electric arc generated will move along the arc-starting plate 13 to the arc-extinguishing grid group 40, thereby ensuring the breaking performance of the circuit breaker.

[0062] Specifically, the width of the arc-starting plate 13 is greater than or equal to the width of the stationary contact 12. As the moving contact 50 moves away from the stationary contact, the arc is conducted from the position of the stationary contact 12 to the arc-starting plate 13, and then to the arc-extinguishing grid group 40 located above the arc-starting plate 13. The fact that the width of the arc-starting plate 13 is greater than the width of the stationary contact 12 is conducive to the diffusion of the arc. This makes it easier for the arc in the arc-starting channel 32a to be guided and diffused, and makes it easier for the arc to be guided to the arc-extinguishing grid group 40, thereby improving the arc-extinguishing performance.

[0063] Specifically, the arc-starting plate 13 is disposed close to the stationary contact 12, and in one embodiment, the stationary contact 12 is made of silver alloy. In order to reduce energy loss during energization and improve resistance to arc erosion, the contact point is usually plated with silver or made of silver alloy (such as silver nickel or silver tin oxide).

[0064] In one embodiment, the arc-initiating plate is made of a ferromagnetic material to create a magnetic reinforcement effect, and its layout near the silver alloy contact of the stationary contact can significantly enhance the magnetic field strength in the contact area. When the circuit breaker breaks, the arc root needs to be quickly transferred from the stationary contact 12 to the arc-initiating plate to avoid burning of the stationary contact 12; and the enhanced magnetic field causes the arc to be rapidly stretched and guided to the arc-extinguishing chamber 20a under the action of the Lorentz force.

[0065] In other embodiments, both the arc-starting plate and the stationary contact are made of silver alloy.

[0066] Specifically, the thickness of the arc-inducing plate 13 is the same as the thickness of the stationary contact 12, the surface of the arc-inducing plate 13 is flush with the surface of the stationary contact 12, and a first vertical suspension gap is formed between the bent extension section 11d and the mounting horizontal plate 11c; a second vertical suspension gap is formed between the arc-inducing plate 13 and the mounting horizontal plate 11c, and the height of the second suspension gap is greater than that of the first suspension gap.

[0067] Traditional arc-starting plate designs typically provide more installation space for the arc-extinguishing grid assembly 40 through warping (such as bending or tilting), while simultaneously guiding the arc into the arc-extinguishing chamber 20a through the tilting angle. In this design, the surface of the arc-starting plate 13 is flush with the surface of the stationary contact 12 (the arc-starting plate 13 is a flat plate). The Z-shaped stacked structure of the stationary contact assembly 10 (connection horizontal plate 11a, connection vertical plate 11b, and mounting horizontal plate 11c) forms a stepped suspended space gap, achieving stepped arc guidance without the need for arc-starting plate warping. The second suspended space gap is also higher, directly providing a vertical expansion channel for the arc and reducing the need for warping guidance.

[0068] Furthermore, the length of the arc-starting plate 13 in the bent extension section 11d is less than or equal to the length of the stationary contact 12; and the length of the arc-starting plate 13 extending beyond the bent extension section 11d is less than or equal to the length of the arc-starting plate 13 in the bent extension section 11d. The flat plate design of the arc-starting plate covers the area of ​​the stationary contact 12, and its width and extension direction have been optimized for magnetic field distribution through a stepped main plate structure, so that the arc can be effectively driven to the arc-extinguishing chamber 20a on the surface of the flat plate without relying on the additional magnetic field generated by warping. In addition, the flat plate structure simplifies the arc-starting plate structure, avoids material stress concentration and assembly errors that may be caused by bending, and improves the reliability and space utilization of the arc-starting plate. This improves the stability of the arc-extinguishing system.

[0069] In this embodiment, the width of the bent extension 11d is smaller than the width of the mounting plate 11c, and the width of the arc-initiating plate 13 is greater than the width of the stationary contact 12, equal to (with an error within 1 mm) the width of the mounting plate 11c. On the one hand, the wider arc-initiating plate 13 can provide a larger conductive contact area, reducing the probability of the arc stagnating on the stationary contact 12 and guiding the arc to quickly enter the arc-extinguishing grid. On the other hand, the arc-initiating plate 13 has a larger surface area, which is beneficial for dispersing the heat generated by the high temperature of the arc and reducing the risk of local overheating. However, an excessively large arc-initiating plate 13 would exceed actual needs, increasing cost and space occupation.

[0070] Reference Figure 4 The narrow bend extension 11d makes the contact area between the stationary contact 12 and the moving contact 50 more concentrated, the current path contracts during disconnection, the generated Lorentz force is stronger, and the contact separation is accelerated. Reducing the width of the bend extension 11d can reduce the opening size of the arc extinguishing chamber 20a (width of the arc ignition channel 32a), and together with the side wall of the gas generating shroud 30, a tighter sealed cavity 32b is formed, which enhances the gas pressure holding effect to assist in arc extinguishing, reduces material usage, lowers costs and improves assembly flexibility.

[0071] Reference Figure 5 In order to improve breaking capacity and reduce material costs, the contact substrate 11 is further provided with a through slot 11e, which extends from the connection between the mounting horizontal plate 11c and the bent extension section 11d to the connecting vertical plate 11b.

[0072] In one embodiment, the bent extension 11d is formed by bending the part of the contact substrate 11 in the opposite direction after separation, and a through slot 11e is formed on the connecting vertical plate 11b and the mounting horizontal plate 11c at the original separation position.

[0073] When the bent extension 11d is formed at the end of the mounting plate 11c through a reverse bending process, the material undergoes plastic deformation. If it is bent directly (through the slot 11e), stress concentration will occur in the bending area, making it difficult to precisely control the bending angle, and the height between the bent extension 11d and the mounting plate 11c will be unstable; unexpected cracks may appear at the bending point, damaging the structural strength.

[0074] In other embodiments, the through slot 11e is formed by cutting the contact substrate 11.

[0075] Specifically, the length of the through slot 11e on the connecting vertical plate 11b is L, where 5mm ≤ L ≤ 15mm. In order to ensure that the bending extension 11d has sufficient height, L is greater than or equal to 5mm. The height of L determines the position of the fulcrum when the bending section bends, and the bending fulcrum moves towards the inside of the second horizontal plate.

[0076] When L = 5mm, it satisfies the installation of the arc-starting plate 13 and the stationary contact 12. As L continues to increase, material costs can be further reduced and competitiveness can be improved. The through slot 11e extends to the connection point between the connecting vertical plate 11b and the wiring horizontal plate 11a. For example, the length of L after extending to the connecting vertical plate 11b is 13mm, 14mm, 15mm, etc.

[0077] Furthermore, the arc-extinguishing grid assembly 40 is located above the arc-starting plate 13. Of course, in other designs, the arc-extinguishing grid assembly 40 adopts a staggered layout, with the end of the arc-starting plate 13 pointing towards the arc-extinguishing grid assembly 40. Alternatively, the arc-extinguishing grid assembly 40 can be arranged to the side or rear.

[0078] Reference Figure 1 and Figure 2 Specifically, the arc-extinguishing grid assembly 40 includes multiple arc-extinguishing plates 42 stacked vertically along the arc-extinguishing chamber 20a. The multiple arc-extinguishing plates 42 have arc-extinguishing gaps 43 between them for cutting the electric arc. An arc-extinguishing gap 43 is also formed between the arc-initiating plate 13 and the closest arc-extinguishing plate 42. In other words, the arc-initiating plate 13 can serve as one of the arc-extinguishing plates 42 in the arc-extinguishing grid assembly 40. The arc-initiating plate directly serves as the first layer of the arc-extinguishing grid, reducing the arc transfer distance from the contact to the arc-extinguishing grid, shortening the distance between the stationary contact and the arc-extinguishing chamber 20a, significantly improving arc-initiating efficiency, allowing the arc to enter the arc-extinguishing grid area more quickly, and reducing contact erosion time. Furthermore, the integrated design of the arc-initiating plate and the arc-extinguishing grid assembly 40 saves space, simplifies assembly, optimizes the internal layout of the circuit breaker, and improves the sealing and gas pressure holding capacity of the arc-extinguishing chamber 20a.

[0079] Reference Figure 2The arc-extinguishing grid assembly 40 is fixed on two partitions 41. The gas-generating hood 30 of the partition 41 is formed by a gas-generating baffle (with an arc-extinguishing baffle wall 31) and a gas-generating side plate (with an arc-extinguishing side plate 32) in a U-shaped groove. The two partitions 41 place the arc-extinguishing grid assembly 40 in the U-shaped groove. The stationary contact assembly 10 is placed at the bottom of the housing, and the gas-generating hood 30 is placed on the stationary contact assembly 10. The gas-generating baffle is fixed on the wiring cross plate 11a because the width of the mounting cross plate 11c is greater than that of the bent extension section 11d. The width of the gas generating hood 30 forms a relief groove. The bottom of the gas generating hood 30 is on the mounting plate 11c. The bent extension section 11d and the arc-starting plate 13 are at the edge of the relief groove, so that a sealed cavity 32b is formed below the bent extension section 11d and the arc-starting plate 13. The upper cover of the circuit breaker covers the housing and forms an arc-extinguishing chamber 20a between the gas generating baffle and the gas generating side plate. The arc-extinguishing grid assembly 40 is placed between the gas generating baffle and the gas generating side plate, and the arc-extinguishing plate 42 is inclined towards the arc outlet 31a.

[0080] Specifically, the wiring horizontal plate 11a is also provided with a wiring port 11a1 and a mounting hole 11a2 for fixing the gas generating hood 30; the wiring port 11a1 completes the stable transmission of electrical energy or signals through a metal conductor; the use of crimping or screw fastening technology ensures low contact resistance and withstands large current; the mounting hole 11a2 is used by the wiring horizontal plate 11a to fix external components (such as the gas generating hood 30, terminal cover or equipment housing), and the gas generating hood 30, arc extinguishing chamber 20a and other accessories are fixed to the wiring horizontal plate 11a by screws or clips to ensure the compactness and vibration resistance of the overall structure.

[0081] Specifically, the surface of the wiring cross plate 11a also has anti-slip texture 11a3. The anti-slip texture 11a3 is a threaded or anti-slip tooth design to prevent the components from shifting due to mechanical vibration during equipment operation.

[0082] In summary, this solution enhances the electrodynamic repulsion force through the design of the stationary contact bending extension section 11d, accelerating the breaking of the moving and stationary contacts and shortening the arcing time, thereby reducing the erosion of the contacts and energy loss caused by the arc. Furthermore, the arc extinguishing chamber 20a adopts a closed space design and a gas generating hood 30 design, utilizing the gas pressure holding effect to quickly cool and extinguish the arc, reducing energy waste and pollution caused by prolonged arcing. Moreover, the application of high-impedance grid assembly can limit short-circuit current and reduce breaking energy, reducing carbon emissions during circuit faults, thereby reducing the arc duration. The contact assembly adopts a modular design, indirectly reducing energy consumption and material losses. Thus, the circuit breaker can improve arc extinguishing efficiency and save material losses, which is highly relevant to the ESG green concept.

[0083] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A circuit breaker, characterized in that, include: A stationary contact assembly includes a contact substrate and a stationary contact, wherein the end of the contact substrate is provided with a bent extension section that bends toward the other end; the stationary contact is disposed on the mounting surface of the bent extension section. An arc-extinguishing chamber assembly includes an arc-extinguishing chamber, an arc-extinguishing grid assembly disposed within the arc-extinguishing chamber, and a gas-generating hood. The gas-generating hood includes an arc-extinguishing baffle and two arc-extinguishing sidewalls disposed opposite to and abutting against the side edge of the bent extension section. The bent extension section, the arc-extinguishing baffle, and the arc-extinguishing sidewalls together enclose and define a sealed cavity.

2. The circuit breaker as described in claim 1, characterized in that, The stationary contact assembly further includes an arc-initiating plate, and the arc-initiating plate and the stationary contact are sequentially arranged on the mounting surface along the extension direction of the bent extension section, with the end of the arc-initiating plate extending beyond the free end of the bent extension section; the arc-extinguishing baffle is in contact with the free end of the arc-initiating plate, and the bent extension section, the arc-initiating plate, the arc-extinguishing baffle, and the arc-extinguishing sidewall together enclose and define the sealed cavity.

3. The circuit breaker as described in claim 2, characterized in that, The width of the bent extension is smaller than the width of the contact substrate; And / or, the width of the arc-initiating plate is greater than or equal to the width of the stationary contact; And / or, the length of the arc-inducing plate in the bent extension section is less than or equal to the length of the stationary contact point; And / or, the length of the arc-initiating plate extending beyond the bent extension is less than or equal to the length of the arc-initiating plate in the bent extension.

4. The circuit breaker as described in claim 1, characterized in that, The contact base plate includes a wiring horizontal plate, a connecting vertical plate and a mounting horizontal plate connected in sequence, and the bent extension section bends from the mounting horizontal plate toward the connecting vertical plate. The contact base plate is also provided with a through slot, which extends from the connection between the mounting horizontal plate and the bent extension section to the connecting vertical plate.

5. The circuit breaker as described in claim 4, characterized in that, The through slot extends to the connection point between the connecting vertical plate and the wiring horizontal plate.

6. The circuit breaker as described in claim 4, characterized in that, The bent extension is formed by partially separating the contact substrate and bending it in the opposite direction, and the through slot is formed on the connecting vertical plate and the mounting horizontal plate at the original separation position.

7. The circuit breaker as claimed in claim 4, characterized in that, The length of the through slot on the connecting vertical plate is L, 5mm≤L≤15mm.

8. The circuit breaker as claimed in claim 4, characterized in that, The wiring cross plate is also provided with a wiring port and mounting holes for fixing the gas generating hood.

9. The circuit breaker as claimed in claim 4, characterized in that, The surface of the wiring cross plate also has anti-slip texture.

10. The circuit breaker as claimed in claim 2, characterized in that, The arc-extinguishing grid assembly is located above the arc-initiating plate; the arc-extinguishing grid assembly includes multiple arc-extinguishing plates stacked vertically along the arc-extinguishing chamber, and an arc-extinguishing gap is formed between the arc-initiating plate and the closest arc-extinguishing plate.

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