Arc extinguishing structure of circuit breaker

Abstract

The invention discloses an arc extinguishing structure of a circuit breaker, which belongs to the technical field of circuit breakers and comprises a static contact assembly, a moving contact assembly and a reverse transmission mechanism. The static contact assembly comprises a static end transmission rod which performs synchronous linear movement with the static contact assembly. The moving contact assembly comprises a moving end transmission rod which performs synchronous linear movement with the moving contact assembly. The reverse transmission mechanism comprises a first connecting rod, a second connecting rod and an arc-shaped guide groove, the two ends of the second connecting rod are hinged to the movable end transmission rod and one end of the first connecting rod respectively, the other end of the first connecting rod is hinged to the static end transmission rod, and a guide pin moving under the constraint path of the arc-shaped guide groove is arranged between the two hinged ends of the first connecting rod. The arc-shaped guide groove replaces a traditional multi-connecting-rod or double-guide-rail structure, only a single guide pin is needed to restrain the motion trail, the sliding freedom degree and the force transmission complexity are reduced, and the clamping stagnation risk is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit breakers, and specifically relates to an arc extinguishing structure of a circuit breaker. Background Art

[0002] As a key protection device in the power system, a circuit breaker has a dedicated arc extinguishing device for opening and closing the circuit. It can not only switch the load current, but also connect and withstand the short-circuit current for a certain period of time, and can automatically trip under the action of the protection device to cut off the short-circuit fault. The arc chamber, as the core component of the circuit breaker, has a crucial impact on the arc extinguishing ability in terms of its structural design, mechanical linkage mode, and spatial layout.

[0003] In the traditional pneumatic arc extinguishing structure, a pneumatic chamber is formed between the cylinder and the piston, and they move together with the contacts. During the opening process, the gas in the pneumatic chamber is compressed. After the gas pressure rises, it pushes the air flow through the nozzle, and the arc burns in the nozzle. This solution has two main technical defects: First, the cylinder assembly requires a piston sealing structure with precise fit, which has high requirements for machining accuracy; second, the moving contact system adopts a single-sided linear drive mode, and the entire mechanical stroke needs to be completed during the opening process to reach the effective arc extinguishing pressure, resulting in a relatively long opening action time.

[0004] The patent with the publication number CN106504940A discloses a double-moving contact transmission device for a circuit breaker. The first pull rod is used for power input, and the reverse transmission device is used to transmit the movement and force of the first pull rod parallel and in the opposite direction to the second arc contact. The two arc contacts open and close simultaneously, which improves the relative speed of the static and dynamic arc contacts and significantly reduces the operating work of the mechanism. However, in this transmission device, in order to ensure the linear movement of the second pull rod and the second arc contact, the transmission link structure in Embodiment 1 needs to cooperate with two pins through two linear guide rails respectively. There are two sliding degrees of freedom in one system, and the force transmission path is very complex, with extremely high requirements for the smooth sliding of the transmission link. The transmission link structure in Embodiment 2 additionally adds two link plates, resulting in a significant increase in the number of link rods and the rotational degrees of freedom. The bilateral reverse movement is prone to jamming. The two structural solutions have unstable actions. Summary of the Invention

[0005] The purpose of the present invention is to provide an arc extinguishing structure of a circuit breaker to solve the problems raised in the above-mentioned prior art.

[0006] An arc extinguishing structure of a circuit breaker is provided, including: A static contact assembly, which includes a static end transmission rod that moves linearly synchronously with the static contact assembly; A moving contact assembly, which includes a moving end transmission rod that moves linearly synchronously with the moving contact assembly; Reverse drive mechanism, which includes a first connecting rod, a second connecting rod and an arc-shaped guide groove. Both ends of the second connecting rod are respectively hinged to the moving-end transmission rod and one end of the first connecting rod. The other end of the first connecting rod is hinged to the static-end transmission rod. There is a guide pin between the two hinged ends of the first connecting rod that moves under the constraint path of the arc-shaped guide groove.

[0007] As a further embodiment of the present invention: At least two moving-end transmission rods are arranged, and a bridge is provided between the multiple moving-end transmission rods. The second connecting rod is hinged to the bridge.

[0008] On the one hand, the bridge plays a role in structural integration, enabling multiple moving-end transmission rods to be connected to form a frame body. The rigid linkage structure of the frame body enhances the lateral bending resistance of the moving-end transmission rods, ensuring that the moving-end transmission rods do not undergo flexural deformation during long-term use. On the other hand, the second connecting rod is hinged to the bridge. The bridge serves as a force transmission bridge between the multiple moving-end transmission rods, converging the forces from multiple paths to the hinge point and transmitting them to the second connecting rod as a unidirectional force, simplifying the force transmission path, minimizing the number of connecting rods to the greatest extent, and avoiding mechanism jamming.

[0009] As a further embodiment of the present invention: There is a sleeve rod provided between at least two moving-end transmission rods, and the static-end transmission rod movably penetrates through the sleeve rod.

[0010] The sleeve rod is sleeved outside the static-end transmission rod, and the moving-end transmission rod and the static-end transmission rod form a nested motion structure. The sleeve rod provides linear motion guidance and radial constraint for the static-end transmission rod, preventing motion deviation, enhancing the stability of the axial movement of the static-end transmission rod, and providing lateral auxiliary support for the static-end transmission rod to resist flexural deformation.

[0011] As a further embodiment of the present invention: The number of the moving-end transmission rods is two, and the moving contact assembly includes a moving-end mounting seat. The two moving-end transmission rods are respectively hinged to the moving-end mounting seat.

[0012] The two moving-end transmission rods are respectively hinged to the moving-end mounting seat to form a symmetric drive structure. The hinge design allows the moving-end transmission rods to finely adjust the angle during movement to compensate for the influence of assembly errors, micro-deformations of the rods, or thermal deformations. In addition, under the limiting action of the static-end transmission rod, the hinge part does not affect the axial movement form of the moving-end transmission rods, eliminating the influence of bending moment on the moving-end transmission rods. The acting force is always transmitted axially, further reducing the adverse effect of jamming between mechanisms.

[0013] As a further embodiment of the present invention: There is a part that fits when closing and a part that connects the cavity between the static contact assembly and the moving contact assembly to the outside when closing between the static contact assembly and the moving contact assembly.

[0014] In the closed state, a relatively sealed cavity structure is formed between the static contact assembly and the moving contact assembly, and only partial communication structures exist to balance the internal and external air pressures, ensuring that there is no need to resist air pressure resistance during the process of the cavity volume shrinking when closing. During the opening process, the gas in the arc heating cavity is heated by the arc, causing the gas to expand and increase pressure rapidly. The gas is output from the communication part and generates a self-energized force on the static contact assembly, which can accelerate the opening of the static contact assembly and the moving contact assembly.

[0015] As a further embodiment of the present invention: the static contact assembly includes a static main contact, the moving contact assembly includes a moving main contact, and a plurality of static end main contact fingers arranged at intervals in the circumferential direction are formed at one end of the static main contact close to the moving main contact.

[0016] The static end main contact fingers are arranged at intervals along the circumference of the static main contact, forming a plurality of independent contact points. During the opening process, an arc is first generated when the moving arc contact and the static arc contact separate, and is attracted to the gap between adjacent static end main contact fingers due to the electric field concentration effect. The interval design of the static end main contact fingers divides a single arc into multiple short arcs. The voltage gradient of each short arc increases, accelerating the arc voltage to rise to the arc extinguishing threshold, and at the same time reducing the energy density of a single arc.

[0017] As a further embodiment of the present invention: a shielding cover is covered on the integrated periphery of several static end main contact fingers of the static main contact.

[0018] The shielding cover is circumferentially arranged around the periphery of the static end main contact fingers, and uses its own metal conductivity to limit the arc to the core area of the cavity where the static end main contact fingers are located, preventing the arc from spreading outwards. The shielding cover optimizes the electric field distribution around the contact fingers through the voltage equalizing effect, avoiding the arc migrating to the non-arc extinguishing area due to electric field distortion, and ensuring that the arc is stable within the controllable range at the end of the contact fingers.

[0019] As a further embodiment of the present invention: one end of the static end main contact finger close to the moving main contact has an arc-shaped plate recessed towards the axis of the static main contact.

[0020] When the arc-shaped plate contacts the moving main contact, it forces the root of the static end main contact finger to produce elastic deformation, ensuring close contact with the moving main contact. The arc-shaped plate lifts the main structure of the static end main contact finger relative to the moving main contact to maintain separation, avoiding the overall contact between the static end main contact finger and the moving main contact all the time in the closed state, which may lead to the inability of the static end main contact finger to immediately participate in arc diversion and segmentation during opening. The intervals of the arc-shaped plates form air flow nozzles for evenly and stably releasing pressure.

[0021] As a further embodiment of the present invention: the end of the shielding cover has a limiting plate extending towards the axis of the static main contact, and the limiting plate is used to restrict the freedom of movement of the arc-shaped plate towards the axis of the static main contact.

[0022] The limiting plate is used to limit the radial movement range of the arc-shaped plate, especially the freedom of movement towards the axis direction, and plays a structural protection role for the static main contact finger. In addition, the limiting plate forms a shielding occlusion at the end of the static main contact finger, restricting the outward release of the arc at the end of the static main contact finger.

[0023] As a further embodiment of the present invention: a plurality of steps are formed on the periphery of the moving main contact relative to the end of the static main contact finger.

[0024] When the arc-shaped plate contacts the step, it forces the root of the static main contact finger to deform, and then a tight fit is formed between the arc-shaped plate and the step. When the pressure in the cavity between the static contact assembly and the moving contact assembly increases and ejects and releases pressure outward, the air flow will encounter the step to form a thrust, generating a self-energized force on the moving contact assembly, further accelerating the opening of the static contact assembly and the moving contact assembly.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The reverse synchronous movement of the static contact assembly and the moving contact assembly is realized through the first connecting rod, the second connecting rod and the arc-shaped guide groove in the reverse transmission mechanism. The second connecting rod transmits the driving force of the moving end transmission rod to the first connecting rod. The guide pin forms a fixed trajectory under the constraint of the arc-shaped guide groove, forcing the static contact assembly and the moving contact assembly to move in opposite directions when opening, shortening the contact separation time.

[0026] 2. The arc-shaped guide groove replaces the traditional multi-link or double-guide rail structure. Only a single guide pin is required to constrain the movement trajectory, reducing the sliding freedom and the complexity of force transmission, and reducing the risk of jamming. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present drawings or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present drawings. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0028] Figure 1 It is a schematic diagram of the overall structure of the arc extinguishing structure of the circuit breaker; Figure 2 It is a schematic diagram of the reverse conduction mechanism provided by the present invention; Figure 3 It is one of the sectional views of the arc extinguishing structure of the circuit breaker; Figure 4 It is the second sectional view of the arc extinguishing structure of the circuit breaker; Figure 5 For Figure 3 The enlarged view of area A in Figure 6Structural schematic diagram of the static end main contact finger provided by the present invention; Figure 7 One of the working state diagrams of the arc extinguishing structure of the circuit breaker; Figure 8 Another working state diagram of the arc extinguishing structure of the circuit breaker.

[0029] In the figure: 1. Static contact assembly; 11. Static main contact; 12. Static end main contact finger; 121. Arc-shaped plate; 13. Shielding cover; 131. Limit plate; 14. Static arc contact; 2. Moving contact assembly; 21. Moving end mounting seat; 22. Moving main contact; 221. Step; 23. Moving arc contact; 3. Reverse transmission mechanism; 31. First connecting rod; 32. Second connecting rod; 33. Arc-shaped guide groove; 34. Guide pin; 41. Static end transmission rod; 42. Moving end transmission rod; 43. Bridge; 44. Sleeve rod; 5. Pull rod. Specific embodiments

[0030] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described and explained below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0031] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacturing or production changes based on the technical content disclosed in the present application are only conventional technical means and should not be understood that the content disclosed in the present application is insufficient.

[0032] However, there will be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters are omitted and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0033] Please refer to Figures 1-4As shown in the figure, the arc extinguishing structure of the circuit breaker in the embodiment of the present invention includes a static contact assembly 1, a moving contact assembly 2, and a reverse transmission mechanism 3. The static contact assembly 1 includes a static end transmission rod 41 that moves linearly synchronously with it. The moving contact assembly 2 includes a moving end transmission rod 42 that moves linearly synchronously with it. The reverse transmission mechanism 3 includes a first connecting rod 31, a second connecting rod 32, and an arc-shaped guide groove 33. Both ends of the second connecting rod 32 are respectively hinged to the moving end transmission rod 42 and one end of the first connecting rod 31. The other end of the first connecting rod 31 is hinged to the static end transmission rod 41. A guide pin 34 that moves under the constraint path of the arc-shaped guide groove 33 is provided between the two hinged ends of the first connecting rod 31.

[0034] One end of the moving contact assembly 2 has a moving end mounting seat 21 that contacts and can slide relatively inside the static contact assembly 1. The moving end transmission rod 42 is arranged on the moving end mounting seat 21. The other end of the moving contact assembly 2 has a pull rod 5 that can drive its movement to control the relative stroke between the moving contact assembly 2 and the static contact assembly 1. A moving arc contact 23 is arranged inside the moving contact assembly 2. The static contact assembly 1 has a static end transmission rod 41 extending towards the reverse transmission mechanism 3 and a static arc contact 14 extending towards the moving arc contact 23. The process of opening and closing is the process of the moving arc contact 23 cooperating with and separating from the static arc contact 14.

[0035] In one embodiment, please refer to Figures 1-4 、 Figures 7-8 As shown in the figure, the moving arc contact 23 and the static arc contact 14 are in an open state. The pull rod 5 pushes the moving contact assembly 2 towards the reverse transmission mechanism 3, thereby driving the moving end transmission rod 42 to axially move towards the reverse transmission mechanism 3, and driving the moving arc contact 23 to move towards the static arc contact 14. The moving end transmission rod 42 applies an axial pressure to one end of the second connecting rod 32. The second connecting rod 32 then transmits the axial force to the first connecting rod 31 to generate a torque forcing the first connecting rod 31 to rotate. At this time, the guide pin 34 on the first connecting rod 31 contacts and presses against the convex arc surface of the arc-shaped guide groove 33. Under the guidance of the convex arc surface of the arc-shaped guide groove 33, the guide pin 34 is forced to move towards the upper end of the arc-shaped guide groove 33. At the same time, when the first connecting rod 31 rotates around the guide pin 34, an axial force is applied to the end hinge of the static end transmission rod 41, forcing the static end transmission rod 41 and the moving end transmission rod 42 to move in the opposite direction. The static end transmission rod 41 then pushes the static arc contact 14 towards the moving arc contact 23. The same-direction movement of the double contacts doubles the relative speed and realizes the closing process faster.

[0036] In one embodiment, please refer to Figures 1-4 、 Figures 7-8As shown, the moving arc contact 23 and the static arc contact 14 are in the closed state. The pull rod 5 pulls the moving contact assembly 2 to move away from the reverse transmission mechanism 3, thereby driving the moving end transmission rod 42 to axially move away from the reverse transmission mechanism 3 and driving the moving arc contact 23 to move away from the static arc contact 14. The moving end transmission rod 42 applies a pulling force to one end of the second connecting rod 32, and the second connecting rod 32 then transmits the axial force to the first connecting rod 31 to generate a torque forcing the first connecting rod 31 to rotate. At this time, the guide pin 34 on the first connecting rod 31 contacts and presses against the concave arc surface on the other side of the arc-shaped guide groove 33. Under the guidance of the concave arc surface of the arc-shaped guide groove 33, the guide pin 34 is forced to move downward along the arc-shaped guide groove 33. At the same time, when the first connecting rod 31 rotates around the guide pin 34, an axial force is applied to the end hinge of the static end transmission rod 41, forcing the static end transmission rod 41 and the moving end transmission rod 42 to move in the opposite direction. The static end transmission rod 41 then drives the static arc contact 14 to move away from the moving arc contact 23. The reverse movement of the double contacts doubles the relative speed, realizes the opening process faster, and accelerates the arc extinguishing process.

[0037] The above embodiment provides the opening and closing process of the single moving end transmission rod 42 solution, while multiple moving end transmission rods 42 can be arranged in the present invention, and the multiple moving end transmission rods 42 are synchronously driven under the drive of the moving contact assembly 2. A bridge 43 is arranged between the multiple moving end transmission rods 42, and the second connecting rod 32 is hinged to the bridge 43.

[0038] The bridge 43 connects multiple moving end transmission rods 42, and converges the driving forces of each rod to a single hinge point at the top of the bridge 43. The bridge 43 disengages the hinge point of the second connecting rod 32 from the end of the single moving end transmission rod 42 and raises it to the top of the bridge 43, forming a long force arm structure. After the hinge point is lifted, the acting point of the driving force of the second connecting rod 32 is far from the fulcrum of the moving end transmission rod 42, equivalently extending the length of the force arm, magnifying the moment, and significantly improving the transmission efficiency.

[0039] When the original single rod hinge point is located at the end of the moving end transmission rod 42, there is an excessive angle between the force transmission direction of the second connecting rod 32 and the axis of the moving end transmission rod 42, which is prone to generate lateral component forces. After raising the hinge point, the force transmission direction of the second connecting rod 32 is closer to the axis of the moving end transmission rod 42, but there is still an acute angle between the second connecting rod 32 and the static end transmission rod 42 towards the first connecting rod 31 direction, ensuring that when closing, the second connecting rod 32 applies a radially outward thrust to the hinge point of the first connecting rod 31, driving the guide pin 34 to move radially outward against the resistance of the arc-shaped guide groove 33, and ensuring that when opening, the second connecting rod 32 applies a radially inward pulling force to the hinge point of the first connecting rod 31, driving the guide pin 34 to move radially inward against the resistance of the arc-shaped guide groove 33, reducing the ineffective component forces by optimizing the force application form.

[0040] The extension structure of the bridge 43 can significantly increase the sectional moment of inertia of the frame body and enhance the bending resistance in the direction of some sections. In addition, the additional moving-end transmission rods 42 converge the stress transmission paths through the bridge 43 and form a single acting force transmitted to the second connecting rod 32. Although the structural strength of the frame body is enhanced by adding rods and the flexural deformation of the structural system is suppressed, the number of degrees of freedom of the entire mechanism is not increased, and the smooth operation of the mechanism is not affected.

[0041] Furthermore, a sleeve rod 44 is arranged between the multiple moving-end transmission rods 42. The sleeve rod 44 is sleeved outside the static-end transmission rod 41 to form a nested guiding structure. The inner wall of the sleeve rod 44 is in clearance fit with the static-end transmission rod 41 to form a lateral auxiliary support, allowing only the static-end transmission rod 41 to slide axially and restricting the radial displacement of the static-end transmission rod 41. Without an additional guide rail or slider structure, the sleeve rod 44 integrates the guiding function through the moving-end transmission rod 42, reducing the system complexity.

[0042] Even further, the number of the moving-end transmission rods 42 is preferably two to prevent a significant offset of the axis of the sleeve rod 44 caused by uneven thermal deformation of each rod when the number of rods is too large. The moving contact assembly 2 includes a moving-end mounting seat 21. The two moving-end transmission rods 42 are respectively hinged to the moving-end mounting seat 21, and the hinged rotation degrees of freedom of the multiple moving-end transmission rods 42 are in the same direction.

[0043] The hinged design of the moving-end transmission rod 42 and the moving-end mounting seat 21 allows the transmission rod to rotate with a single degree of freedom around the hinge point, forming a flexible joint structure. During the opening and closing processes, the moving-end transmission rod 42 may undergo slight deformation due to assembly errors, thermal expansion, or mechanical loads, resulting in sliding jamming between the sleeve rod 44 and the static-end transmission rod 41. When the moving-end transmission rod undergoes slight flexural deformation, the hinge point allows the moving-end transmission rod 42 to rotate around the axis, releasing local stress and avoiding plastic deformation caused by rigid connection. The hinged design does not limit the axial movement degree of freedom of the moving-end transmission rod 42. Even if the rod undergoes a slight change in length due to thermal expansion, it can still be adaptively adjusted through hinged rotation to ensure that the driving force is transmitted along the axis.

[0044] It should be noted here that the hinge only allows the moving-end transmission rod 42 to rotate around a single axis and does not introduce additional translational or rotational degrees of freedom to the entire transmission system. The driving force of the moving-end transmission rod 42 is always transmitted axially, and the hinged rotation is only used to compensate for minor angular deviations.

[0045] It should be further noted that the guide pin 34 slides within the arc-shaped guide groove 33. The movement trajectory of the guide pin 34 is restricted by the arc-shaped guide groove 33, and only allows the first link 31 and the second link 32 to convert the axial driving force of the moving-end transmission rod 42 into the reverse axial movement of the static-end transmission rod 41 through the cooperative movement along a fixed path, thereby enabling the reverse transmission mechanism 3 to form a self-sustaining structure. Although there is a formally rotation-free end between the moving-end transmission rod 42 and the moving-end mounting seat 21, under the support of the reverse transmission mechanism 3, the static-end transmission rod 41 only bears the acting force of the first link 31 all the time, and the moving-end transmission rod 42 will not collapse under the self-sustaining force and apply force to the rod body of the static-end transmission rod 41, avoiding the radial force on the static-end transmission rod 41 from causing flexural deformation.

[0046] Between the static contact assembly 1 and the moving contact assembly 2, there are parts that fit together during closing and parts that connect the cavity between the static contact assembly 1 and the moving contact assembly 2 to the outside during closing. During opening, the moving arc contact 23 separates from the static arc contact 14 to generate an arc. The high-temperature arc light quickly heats the arc extinguishing gas (such as SF6 or air) in the cavity, causing the gas volume to expand rapidly. The semi-closed space makes it impossible for the gas to be discharged immediately after heating and expansion, forming a high-pressure environment. In the closed state, the cavity is balanced with the external air pressure through a partial connection structure. During opening, the high-pressure gas is ejected directionally through the connection structure, and the reaction force of the ejected gas is applied to the static contact assembly 1 or the moving contact assembly 2, forming a self-energy opening force. The self-energy thrust is superimposed on the mechanical bidirectional driving force, increasing the contact separation speed and significantly reducing the arc extinguishing time. In addition, when the high-pressure gas is ejected from the connection structure, it forms a directional gas blast that directly acts on the root of the arc, accelerating the arc extinction.

[0047] In one embodiment, please refer to Figures 3-6 As shown, the static contact assembly 1 includes a static main contact 11, and the moving contact assembly 2 includes a moving main contact 22. At one end of the static main contact 11 close to the moving main contact 22, a plurality of static-end main contact fingers 12 are formed at intervals along the circumferential direction, forming a structure with alternating multi-contact fingers and gaps. The connection part between the cavity between the static contact assembly 1 and the moving contact assembly 2 and the outside is formed between the gap structures of the static-end main contact fingers 12.

[0048] When the moving arc contact 23 separates from the static arc contact 14, the arc is forced to be divided into multiple short arcs by the gaps of the static-end main contact fingers 12. The voltage gradient of each short arc increases, accelerating the arc voltage to reach the arc extinguishing threshold. The gaps of the static-end main contact fingers 12 directly connect the cavity to the outside, and the high-pressure gas blows the root of the arc on the contact fingers through the gaps, forming the main arc extinguishing air flow. The interval arrangement of the static-end main contact fingers 12 forms multiple independent contact points. During closing, the moving main contact 22 contacts the end of the static-end main contact finger 12, forcing the root of the contact finger to produce elastic deformation, forming an adaptive contact pressure to ensure accurate alignment when the contacts are closed and avoid skewing.

[0049] Furthermore, a shielding cover 13 is integrally covered around the static main contact 11 on the periphery of a number of static end main contact fingers 12. The annular space formed between the shielding cover 13 and the static end main contact fingers 12 serves as a diversion channel for high-pressure gas. During opening, the cavity gas jets out at high speed through this channel. The direction of the channel is parallel to the axis of the contacts of the static end main contact fingers 12, and the gas flow directly impacts the root of the contact arc, longitudinally stretching the arc. The circumferential enclosure design of the shielding cover 13 simultaneously realizes physical isolation of the arc and directional diversion of the gas flow, eliminating the need for additional diversion plates or insulating partitions, resulting in a compact structure and high functional integration.

[0050] In a specific embodiment, a number of static end main contact fingers 12 are connected to each other at one end to form an integral structure. The integral end of the static end main contact fingers 12 is sleeved around the periphery of the static main contact 12. The shielding cover 13 is press-fitted onto the periphery of the static end main contact fingers 12 to fix the static end main contact fingers 12, ensuring uniform deformation of the multiple static end main contact fingers 12. There is a fitting part and a separated part between the shielding cover 13 and the static end main contact fingers 12. The separated part provides a deformable space for the static end main contact fingers 12. The sidewall structure formed by the end side of the static main contact 11, the end side of the static end main contact fingers 12, and the end side of the inward extension part of the shielding cover 13 provides a working surface for the high-pressure gas to exert a thrust force on the static contact assembly 1.

[0051] Furthermore, one end of the static end main contact finger 12 close to the moving main contact 22 has an arc-shaped plate 121 that is recessed towards the axis of the static main contact 11. The arc-shaped plate 121 is recessed towards the axis of the static main contact 11. When contacting the moving main contact 21, elastic deformation occurs at the root of the contact finger due to the lever effect, forming a continuous self-adaptive contact pressure.

[0052] The arc-shaped plate 121 raises the main structure of the static end main contact finger 12, maintaining a small gap with the moving main contact 21. During closing, only the arc-shaped plate 121 contacts the moving main contact 21, and the main body of the contact finger is in a separated state from the moving main contact 21. During opening, it ensures that the main body of the contact finger quickly participates in arc extinguishing. The arc is divided and diverted at the initial stage of opening, preventing the arc from concentrating on burning the contact point and shortening the arc extinguishing time.

[0053] A number of steps 221 are formed around the periphery of the moving main contact 22 and are arranged opposite to the ends of the static end main contact fingers 12. During closing, the step 211 of the moving main contact 21 presses the arc-shaped plate 121, and the elastic deformation of the root of the contact finger absorbs the mechanical impact. When the opening action occurs, during the separation process of the arc-shaped plate 121 from the step 211, the elastic restoring force of the arc-shaped plate 121 is quickly released, applying a reverse thrust to the step 211 to accelerate the reset, ensuring the immediacy of the opening action.

[0054] In addition, during opening, the high-pressure gas in the cavity jets out at high speed through the gap of the static-end main contact finger 12 or the nozzle of the arc-shaped plate 121, directly impacting the surface of the step 211 on the periphery of the moving main contact 21. The impact force of the gas on the step 211 is converted into a self-energizing thrust that pushes the moving main contact 21 to move in the reverse direction.

[0055] The end of the shielding cover 13 is provided with a limiting plate 131 extending towards the axis of the static main contact 11. During opening, an arc is generated at the end of the static-end main contact finger 12. The shielding of the limiting plate 131 confines the arc within the core area between the end of the contact finger and the moving main contact 21, preventing the arc from spreading outwards to the outer edge of the shielding cover 13 or the wall of the arc extinguishing chamber.

[0056] It should be noted that this application is not limited to the above embodiments. The above embodiments are only examples. Embodiments with the same structure in essence as the technical idea and achieving the same effect within the scope of the technical solution of this application are all included in the technical scope of this application. In addition, within the scope of not departing from the main idea of this application, various deformations that those skilled in the art can think of applied to the embodiments, as well as other ways constructed by combining some constituent elements in the embodiments, are also included in the scope of this application.

Claims

1. An arc extinguishing structure for a circuit breaker, characterized in that, Comprising: A static contact assembly (1), which includes a static end transmission rod (41) that moves linearly in synchronization with the static contact assembly (1); A moving contact assembly (2), which includes a moving end transmission rod (42) that moves linearly in synchronization with the moving contact assembly (2); A reverse transmission mechanism (3), which includes a first connecting rod (31), a second connecting rod (32), and an arc-shaped guide groove (33). Both ends of the second connecting rod (32) are respectively hinged to the moving end transmission rod (42) and one end of the first connecting rod (31). The other end of the first connecting rod (31) is hinged to the static end transmission rod (41). A guide pin (34) that moves under the constraint path of the arc-shaped guide groove (33) is provided between the two hinged ends of the first connecting rod (31).

2. The arc extinguishing structure of a circuit breaker according to claim 1, characterized in that, At least two moving end transmission rods (42) are arranged, and a bridge (43) is provided between the multiple moving end transmission rods (42). The second connecting rod (32) is hinged to the bridge (43).

3. The arc extinguishing structure of a circuit breaker according to claim 2, characterized in that, There is at least one sleeve rod (44) provided between at least two moving end transmission rods (42), and the static end transmission rod (41) movably penetrates through the sleeve rod (44).

4. A circuit breaker arc extinguishing structure according to claim 3, characterized in that, The number of the moving end transmission rods (42) is two, and the moving contact assembly (2) includes a moving end mounting seat (21). The two moving end transmission rods (42) are respectively hinged to the moving end mounting seat (21).

5. A circuit breaker arc extinguishing structure according to claim 1, characterized in that, There is a part that fits when closing and a part that communicates the cavity between the static contact assembly (1) and the moving contact assembly (2) with the outside when closing between the static contact assembly (1) and the moving contact assembly (2).

6. A circuit breaker arc extinguishing structure according to claim 5, characterized in that, The static contact assembly (1) includes a static main contact (11), and the moving contact assembly (2) includes a moving main contact (22). A plurality of static end main contact fingers (12) arranged at intervals in the circumferential direction are formed at one end of the static main contact (11) close to the moving main contact (22).

7. The arc extinguishing structure of a circuit breaker according to claim 6, characterized in that, A shielding cover (13) is covered on the integrated periphery of the plurality of static end main contact fingers (12) of the static main contact (11).

8. The arc extinguishing structure of a circuit breaker according to claim 7, characterized in that, One end of the static end main contact finger (12) close to the moving main contact (22) has an arc-shaped plate (121) that is recessed toward the axis of the static main contact (11).

9. The arc extinguishing structure of a circuit breaker according to claim 8, characterized in that, The end of the shielding cover (13) has a limiting plate (131) that extends toward the axis of the static main contact (11). The limiting plate (131) is used to restrict the degree of freedom of the arc-shaped plate (121) to move toward the axis of the static main contact (11).

10. A circuit breaker arc extinguishing structure according to claim 7, characterized in that, A plurality of steps (221) are formed on the periphery of the moving main contact (22) opposite to the ends of the static end main contact fingers (12).

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