Primary and secondary fusion pole-mounted circuit breaker

Abstract

The invention discloses a primary and secondary fusion pole-mounted circuit breaker, which comprises a shell, an isolating switch unit and a vacuum arc-extinguishing chamber unit, a main explosion-proof hole is formed in the bottom wall plate of the shell, and a main explosion-proof assembly is arranged on the bottom wall plate of the shell and below the main explosion-proof hole; an anti-explosion cover is fixed at the lower part of the bottom wall plate and covers the main anti-explosion assembly; the main anti-explosion assembly comprises a main mounting seat and a main anti-explosion sheet, the main mounting seat is annular and fixedly connected with the bottom wall plate, and the main anti-explosion sheet is arranged on the inner side of the main mounting seat and right faces the main anti-explosion hole; the peripheral edge of the main explosion-proof sheet is pressed by the main mounting seat, and a main sealing ring is arranged between the peripheral edge of the main explosion-proof sheet and the bottom wall plate; a through hole is formed in the explosion-proof cover; the explosion-proof structure is integrated at the bottom of the shell, the main explosion-proof sheet is directionally exploded to form a pressure relief channel when the interior of the shell is overpressure, and the external explosion-proof cover provides buffer protection, so that the safety is remarkably improved, and the maintenance is convenient.

Description

Technical Field

[0001] This invention belongs to the field of circuit breaker structural design, and particularly relates to a pole-mounted circuit breaker with built-in isolation that integrates primary and secondary circuit breakers. Background Technology

[0002] Pole-mounted circuit breakers are key protection and control devices for overhead power distribution lines. They are typically installed on poles and are responsible for closing, carrying, and interrupting fault currents. To simplify the line structure, reduce the footprint, and achieve a clear isolation break, the industry commonly adopts a vacuum circuit breaker design with the disconnecting switch built-in. This "built-in isolation" pole-mounted circuit breaker encapsulates the vacuum interrupter and isolating stationary contacts, among other components, within a sealed metal gas-filled housing (filled with SF6 or dry air).

[0003] However, while this compact, integrated design brings structural advantages, it also introduces a long-neglected but potentially high-risk safety issue: the challenge of releasing internal fault arc pressure. When extreme faults occur inside the equipment, such as vacuum interrupter failure, insulation degradation leading to internal flashover, or prolonged current-carrying overheating causing contact point welding, an arc plasma with temperatures reaching thousands of degrees Celsius and pressure escalating rapidly will be instantly generated within the sealed chamber. Because components such as the disconnector are located in the same chamber, the fault energy is completely confined within the casing, and the pressure has nowhere to be released.

[0004] Currently, most traditional primary and secondary integrated pole-mounted circuit breakers on the market still focus on insulation performance, mechanical life, and breaking capacity in their design. For internal arc faults, they mainly rely on the mechanical strength of the casing itself to "passively withstand" them. This design approach has obvious flaws: First, to control the overall weight and cost of the pole-mounted equipment, there is a physical upper limit to the casing strength; second, once the internal pressure exceeds the critical value, the casing (especially the insulating cylinder) will undergo a catastrophic physical explosion. The fragments generated by the explosion (such as epoxy resin sheets and metal parts) will fly at high speed from a height of several meters or even tens of meters, which can easily cause serious secondary accidents such as casualties on the ground, short circuits and tripping of adjacent lines, or even fires, posing a huge safety hazard. Summary of the Invention

[0005] The purpose of this invention is to provide a primary and secondary integrated pole-mounted circuit breaker to solve the safety hazard of existing pole-mounted circuit breakers having a risk of casing explosion due to the inability to reliably release internal fault pressure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a primary and secondary integrated pole-mounted circuit breaker, comprising a housing, and a disconnecting switch unit and a vacuum interrupter unit arranged in series within the housing; a main explosion-proof hole is provided on the bottom wall plate of the housing, and a main explosion-proof assembly is mounted on the bottom wall plate of the housing below the main explosion-proof hole; an explosion-proof cover is fixed to the lower part of the bottom wall plate and covers the outside of the main explosion-proof assembly; the main explosion-proof assembly includes a main mounting base and a main explosion-proof sheet, the main mounting base is annular and fixedly connected to the bottom wall plate of the housing, the main explosion-proof sheet is disposed on the inner side of the main mounting base and faces the main explosion-proof hole; the periphery of the main explosion-proof sheet is pressed by the main mounting base, and a main sealing ring is provided between the periphery of the main explosion-proof sheet and the bottom wall plate; the explosion-proof cover has a through opening.

[0008] Preferably, the inner periphery of the main mounting base is provided with a downwardly recessed support step, and the periphery of the main explosion-proof sheet overlaps on the support step.

[0009] Preferably, a main support frame is fixed to the side of the main explosion-proof sheet facing the main explosion-proof hole, and the main support frame has a hollow structure.

[0010] Preferably, the main support frame has an annular portion that matches the shape of the main explosion-proof hole, and the orthographic projection of the annular portion is located within the inner contour range of the main mounting base; the main sealing ring is sleeved on the outer periphery of the annular portion.

[0011] Preferably, the annular portion is provided with an upwardly protruding positioning post, and the edge of the main explosion-proof hole is provided with a positioning groove for insertion into the positioning post.

[0012] Preferably, the periphery of the main explosion-proof sheet and the main sealing ring are pressed between the main mounting base and the bottom wall plate.

[0013] Preferably, a first fastening bolt is welded and fixed to the lower surface of the bottom wall plate, and a first fastening hole is provided on the main mounting base for the first fastening bolt to pass through. After the lower end of the first fastening bolt passes through the first fastening hole, a first fastening nut is screwed on.

[0014] Preferably, a second fastening bolt is welded and fixed to the lower surface of the bottom wall plate of the housing, and a fixing hole is provided on the explosion-proof cover for the lower end of the second fastening bolt to pass through. The second fastening bolt is provided with a downward-facing stop surface, which abuts against the explosion-proof cover. After the lower end of the second fastening bolt passes through the fixing hole, a second fastening nut is screwed and fixed thereon.

[0015] Preferably, the bottom wall plate is further provided with an auxiliary explosion-proof hole, and an auxiliary explosion-proof assembly is installed below the auxiliary explosion-proof hole and on the bottom wall plate of the housing. The auxiliary explosion-proof assembly is located inside the explosion-proof cover. The auxiliary explosion-proof assembly includes an auxiliary mounting base and an auxiliary explosion-proof sheet. The auxiliary mounting base is annularly fixedly connected to the bottom wall plate, and the auxiliary explosion-proof sheet is located inside the auxiliary mounting base and directly opposite the auxiliary explosion-proof hole. The periphery of the auxiliary explosion-proof sheet is pressed tightly by the auxiliary mounting base, and an auxiliary sealing ring is provided between the periphery of the auxiliary explosion-proof sheet and the bottom wall plate. A rigid partition is provided inside the explosion-proof cover to isolate the spaces corresponding to the main explosion-proof sheet and the auxiliary explosion-proof sheet, forming a main pressure relief chamber and an auxiliary pressure relief chamber. Furthermore, a pressure coordination mechanism is also included, the pressure coordination mechanism including a pressure relief chamber located on the main pressure relief chamber. The system includes a movable plate within the pressure chamber, a support plate and a limiting pin disposed within the auxiliary pressure relief chamber, and a flexible cable connecting the movable plate and the limiting pin. The movable plate is located below the main explosion-proof sheet and is supported by the explosion-proof cover via a first return spring. One end of the support plate is hinged to the auxiliary mounting base, and the other end is normally supported and limited by the limiting pin, keeping the support plate in a horizontal supporting state to support the auxiliary explosion-proof sheet. One end of the flexible cable is fixed to the movable plate, and the other end passes through a rigid partition and is connected to the limiting pin. When the main explosion-proof sheet explodes, causing the movable plate to be compressed and moved downward, the flexible cable pulls the limiting pin away from the supporting position, allowing the support plate to flip under the action of gravity or elastic force, thereby removing the support for the auxiliary explosion-proof sheet.

[0016] Preferably, the limiting pin is slidably disposed in the guide hole of the auxiliary mounting base and is provided with a second return spring, the second return spring providing a preload force to the limiting pin toward the support position; the auxiliary mounting base or the rigid partition or explosion-proof cover is equipped with a guide pulley, and the flexible cable passes around the guide pulley;

[0017] A torsion spring is provided on the hinge shaft between the support plate and the auxiliary mounting base to provide a downward flipping torque for the support plate.

[0018] The positive effects of this invention are as follows: This invention optimizes the design of the primary and secondary integrated pole-mounted circuit breaker structure. First, by integrating an explosion-proof structure consisting of a main explosion-proof hole, a main explosion-proof component, and an explosion-proof cover at the bottom of the circuit breaker housing, the main mounting base of the main explosion-proof component presses the main explosion-proof sheet and the main sealing ring tightly against the bottom wall plate of the housing, forming a highly reliable static seal under normal conditions, ensuring the airtightness of the equipment during normal operation. Simultaneously, the main explosion-proof sheet, as a pressure relief element, can preferentially directionally burst when the internal fault pressure exceeds the limit, causing the main explosion-proof sheet to detach from the overlap with the main mounting base, thereby forming a pressure relief channel. The external explosion-proof cover provides buffering and protection for this relief process, preventing the main explosion-proof sheet from exploding. This integrated modular design not only effectively reduces the risk of overall housing cracking and improves safety, but also facilitates independent installation and replacement, reducing maintenance costs and complexity. Furthermore, by installing auxiliary explosion-proof components and a pressure coordination mechanism within the same explosion-proof enclosure, graded pressure relief is achieved. Specifically, the main explosion-proof sheet, acting as the first line of defense for rapid response, releases pressure from most common faults. Its priority action simultaneously removes the back support of the auxiliary explosion-proof sheet via flexible cables, dynamically lowering the latter's burst threshold from a preset high value, thus transforming it into a backup defense line for extreme faults. This not only ensures safety through physical redundancy but also prevents accidental activation of the backup channel. In addition, the scheme uses rigid partitions to ensure the independence of the backup channel; the flipped state of the support plate 236 also provides a clear mechanical fault indication, offering a clear reference for operation and maintenance; and all actions are confined within the explosion-proof enclosure 22, preventing the splashing of shattered fragments or moving parts, thereby enhancing safety. Attached Figure Description

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

[0020] Figure 1 This is a front view of the primary and secondary integrated pole-mounted circuit breaker in this invention.

[0021] Figure 2 This is a three-dimensional schematic diagram of the primary and secondary integrated pole-mounted circuit breaker in this invention.

[0022] Figure 3 This is a cross-sectional view of the installation location of the main explosion-proof component in this invention.

[0023] Figure 4 This is an exploded view of the main explosion-proof component in this invention.

[0024] Figure 5This is a three-dimensional schematic diagram of the bottom wall plate in this invention.

[0025] Figure 6 This is a schematic diagram of another embodiment of the present invention.

[0026] Figure 7 for Figure 6 A magnified view of a portion of point A in the middle.

[0027] The reference numerals in the figure are as follows: 1. Housing; 11. Bottom wall plate; 111. Main explosion-proof hole; 111b. Auxiliary explosion-proof hole; 112. Positioning slot; 113. First fastening bolt; 114. First fastening nut; 115. Second fastening bolt; 1151. Stop surface; 116. Second fastening nut; 117. Fixing bracket; 21. Main explosion-proof assembly; 211. Main mounting base; 211b. Auxiliary mounting base; 2111. Support step; 2112. First fastening hole; 212. Main explosion-proof sheet; 212b. Auxiliary explosion-proof sheet; 213. Main sealing ring; 213b, auxiliary sealing ring; 214, main support frame; 2141, annular part; 2142, positioning post; 214b, auxiliary support frame; 22, explosion-proof cover; 221, opening; 222, fixing hole; 225, main pressure relief chamber; 227, rigid partition; 228, auxiliary pressure relief chamber; 231, movable plate; 232, first return spring; 233, second return spring; 234, guide pulley; 235, flexible cable; 236, support plate; 2361, hinge shaft; 2362, buffer pad; 237, limit pin. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention. Example 1

[0030] The structure of the primary and secondary integrated pole-mounted circuit breaker in this embodiment of the invention is as follows: Figures 1 to 5As shown, it includes a housing 1, and a disconnecting switch unit and a vacuum interrupter unit arranged in series within the housing 1; a main explosion-proof hole 111 is provided on the bottom wall plate 11 of the housing 1, and a main explosion-proof assembly 21 is mounted on the bottom wall plate 11 of the housing 1 below the main explosion-proof hole 111; an explosion-proof cover 22 is fixed to the lower part of the bottom wall plate 11 and covers the outside of the main explosion-proof assembly 21; the main explosion-proof assembly 21 includes a main mounting base 211 and a main explosion-proof sheet 212, preferably the main explosion-proof sheet 212 is made of stainless steel, such as with a thickness of 0. 0.3mm, 0.4mm, or 0.5mm; the main mounting base 211 is annular and fixedly connected to the bottom wall plate 11; the main explosion-proof sheet 212 is located on the inner side of the main mounting base 211 and is directly opposite the main explosion-proof hole 111; the periphery of the main explosion-proof sheet 212 is pressed by the main mounting base 211, and a main sealing ring 213 is clamped between the periphery of the main explosion-proof sheet 212 and the bottom wall plate 11, the main sealing ring 213 being made of rubber or silicone; the explosion-proof cover 22 has a through hole 221 for depressurization.

[0031] This embodiment integrates a main explosion-proof structure at the bottom of the circuit breaker housing 1, consisting of a main explosion-proof hole 111, a main explosion-proof component 21, and an explosion-proof cover 22. In this main explosion-proof structure, the main mounting base 211 presses the main explosion-proof sheet 212 and the main sealing ring 213 tightly against the bottom wall plate 11 of the housing 1, forming a highly reliable static seal under normal conditions, ensuring the airtightness of the equipment during normal operation. At the same time, the main explosion-proof sheet 212, as a pressure relief element, can preferentially burst in a directional manner when the internal fault pressure exceeds the limit, causing the main explosion-proof sheet 212 to detach from the overlap with the main mounting base 211, thereby forming a pressure relief channel. The externally installed explosion-proof cover 22 provides buffering and protection for this relief process, preventing the main explosion-proof sheet 212 from exploding. This integrated modular design not only effectively reduces the risk of the housing 1 exploding as a whole and improves safety, but also facilitates independent installation and replacement, reducing maintenance costs and complexity.

[0032] The explosion-proof working principle in this embodiment is as follows: Under normal working conditions, the internal pressure of the housing 1 is normal, and the pressure acting on the inner side of the main explosion-proof sheet 212 is lower than its burst threshold. The main explosion-proof sheet 212 is kept sealed by the main sealing ring 213 under the clamping force of the main mounting base 211, and the explosion-proof cover 22 provides external protection. When the housing 1 experiences internal arcing or other faults, the internal pressure rises sharply and is concentrated on the main explosion-proof sheet 212 through the main explosion-proof hole 111. Once the pressure exceeds its design burst value, the edge of the main explosion-proof sheet 212 is partially or completely detached from the main mounting base 211, thereby opening the pressure relief channel. The high-pressure hot gas then rushes out and enters the buffer space formed by the explosion-proof cover 22. After expansion and deceleration, the pressure is quickly released through the opening 221, thereby protecting the integrity of the housing structure.

[0033] See Figure 3 and Figure 4 The inner periphery of the main mounting base 211 is provided with a downwardly recessed support step 2111, and the periphery of the main explosion-proof sheet 212 overlaps on the support step 2111. This design provides an upward support step 2111 on the inner periphery of the main mounting base 211, allowing the periphery of the main explosion-proof sheet 212 to overlap, providing a stable annular bearing surface for the main explosion-proof sheet 212. This ensures that the main explosion-proof sheet 212 does not shift or twist during installation, and that the pressure can be evenly distributed across its entire effective surface.

[0034] Continue reading Figure 3 and Figure 4 A main support frame 214 is fixed to the side of the main explosion-proof sheet 212 facing the main explosion-proof hole 111. For example, the main support frame 214 is bonded to the main explosion-proof sheet 212. The main support frame 214 has a hollow structure and an annular portion 2141 that matches the shape of the main explosion-proof hole 111. The orthographic projection of the annular portion 2141 is located within the inner contour range of the main mounting base 211 (i.e., the annular portion 2141). (The outer diameter of the main support 214 is smaller than the inner diameter of the main mounting base 211). Through the coordinated action of the main support frame 214 and the support step 2111, the overall rigidity and stability of the main explosion-proof sheet 212 under normal pressure are enhanced, further ensuring its reliable operation. In addition, the main sealing ring 213 is sleeved on the outer periphery of the annular portion 2141, so that during assembly, the main sealing ring 213 can be first sleeved on the periphery of the annular portion 2141, and then the whole assembly can be installed into the main mounting base 211, which is convenient for assembly. Preferably, the main support frame 214 is made of plastic material, such as nylon.

[0035] See Figure 4 and Figure 5 The annular portion 2141 is provided with an upwardly protruding positioning post 2142, and the edge of the main explosion-proof hole 111 is provided with a positioning slot 112 that is inserted into the positioning post 2142. The positioning post 2142 and the positioning slot 112 cooperate to position the main support frame 214, ensuring the stability of the installation.

[0036] In this embodiment, the periphery of the main explosion-proof sheet 212 and the main sealing ring 213 are pressed between the main mounting base 211 and the bottom wall plate 11, thereby forming a continuous and tight static sealing line between the periphery of the main explosion-proof sheet 212, the main sealing ring 213 and the bottom wall plate 11, so as to ensure the airtightness of the main explosion-proof hole 11 during long-term operation.

[0037] In this embodiment, a first fastening bolt 113 is welded and fixed to the lower surface of the bottom wall plate 11, so that the first fastening bolt does not need to penetrate the bottom wall plate 11, thus ensuring the sealing of the installation part of the first fastening bolt 113; the main mounting base 211 is provided with a first fastening hole 2112 for the first fastening bolt 113 to pass through, and the lower end of the first fastening bolt 113 passes through the first fastening hole 2112 and is screwed with a first fastening nut 114, thereby fixing the main mounting base 211 to the lower surface of the bottom wall plate 11.

[0038] See Figure 3 and Figure 4 A second fastening bolt 115 is welded and fixed to the lower surface of the bottom wall plate 11 of the housing 1. In this way, the second fastening bolt 115 does not need to penetrate the bottom wall plate 11, so as to ensure the sealing of the installation part of the second fastening bolt 115. The explosion-proof cover 22 is provided with a fixing hole 222 for the lower end of the second fastening bolt 115 to pass through. The second fastening bolt 115 is provided with a downward-facing stop surface 1151. The stop surface 1151 abuts against the explosion-proof cover 22. After the lower end of the second fastening bolt 115 passes through the fixing hole 222, a second fastening nut 116 is screwed and fixed, thereby fixing the explosion-proof cover 22 to the lower surface of the bottom wall plate 11.

[0039] See Figure 1 and Figure 2 As shown, the lower surface of the bottom wall plate 11 is fixed with fixing brackets 117 on both sides of the explosion-proof cover 22, and the lower edge of the explosion-proof cover 22 is higher than the lower edge of the fixing brackets 117. The built-in isolating circuit breaker can be fixed by the fixing brackets 117 during installation. When the built-in isolating circuit breaker is subjected to a side collision during transportation and installation, the fixing brackets 117 will resist the force before the protruding explosion-proof cover 22, so as to avoid the explosion-proof cover 22 from being directly impacted and damaged. Example 2

[0040] This embodiment is a further optimization based on Embodiment 1: See [link / reference] Figure 6 and Figure 7As shown, an auxiliary explosion-proof hole 111b is also provided on the bottom wall plate 11 of the housing 1. An auxiliary explosion-proof component is installed below the auxiliary explosion-proof hole 111b. The auxiliary explosion-proof component is located inside the explosion-proof cover 22. A pressure coordination mechanism is also installed inside the explosion-proof cover 22. The auxiliary explosion-proof component includes an auxiliary mounting base 211b, an auxiliary explosion-proof sheet 212b, and an auxiliary sealing ring 213b. The auxiliary sealing ring 213b is made of rubber or silicone. Preferably, the auxiliary explosion-proof sheet 212b is made of stainless steel, and its thickness can be set to 0. 0.3mm, 0.4mm, or 0.5mm; the auxiliary mounting base 211b is annular and is fixedly connected to the bottom wall plate 11 by means of, for example, bolts; the auxiliary explosion-proof sheet 212b is located on the inner side of the auxiliary mounting base 211b and is directly opposite the auxiliary explosion-proof hole 111b; the periphery of the auxiliary explosion-proof sheet 212b is pressed by the auxiliary mounting base 211b, and at the same time, an auxiliary sealing ring 213b is clamped between the periphery of the auxiliary explosion-proof sheet 212b and the bottom wall plate 11, thereby forming a reliable static seal.

[0041] A rigid partition 227 is fixedly installed inside the explosion-proof cover 22. The rigid partition 227 divides the interior of the explosion-proof cover 22 into two chambers: one is the main pressure relief chamber 225 surrounding the main explosion-proof component 21, and the other is the auxiliary pressure relief chamber 228 surrounding the auxiliary explosion-proof component. The rigid partition 227 forms a barrier between the two chambers to prevent a large amount of gas from rushing into the auxiliary pressure relief chamber 228 when the main pressure relief chamber 225 is depressurized, thus avoiding interference with the operation of the auxiliary explosion-proof component.

[0042] The pressure coordination mechanism includes a movable plate 231 disposed in the main pressure relief chamber 225, a support plate 236 and a limiting pin 237 disposed in the auxiliary pressure relief chamber 228, and a flexible cable 235 connecting the movable plate 231 and the limiting pin 237. The movable plate 231 is located below the main explosion-proof sheet 212 and can move up and down. The movable plate 231 is supported by the explosion-proof cover 22 by a first return spring 232. Specifically, a guide post can be provided at the bottom of the movable plate 231. After the lower end of the guide post passes through the explosion-proof cover 22, a retaining spring is provided for stop and limit. The first return spring 232 is sleeved on the guide post, and its upper and lower ends act on the movable plate 231 and the explosion-proof cover 22, respectively. One end of the support plate 236 is hinged to the auxiliary mounting base 2. On 11b, the other end is supported and limited by the limiting pin 237 under normal conditions, so that the support plate 236 maintains a horizontal support state to support the auxiliary explosion-proof sheet 212b; one end of the flexible cable 235 is fixedly connected to the movable plate 231, and the other end passes through the rigid partition 227 and is connected to the limiting pin 237; when the main explosion-proof sheet 212 explodes and causes the movable plate 231 to be compressed and moved downward, the flexible cable 235 pulls the limiting pin 237 away from the support position, so that the support plate 236 flips under the action of gravity or elastic force, thereby removing the upward support for the auxiliary explosion-proof sheet 212b; in this scheme, by setting the main and auxiliary explosion-proof sheets and setting the pressure coordination mechanism in the same explosion-proof cover 22, the purpose of graded pressure relief is achieved.

[0043] The working principle of the scheme in this embodiment is as follows: When a fault occurs inside the circuit breaker, the pressure rises suddenly, causing the main explosion-proof sheet 212 to burst. The high-pressure gas flow released instantly and the main explosion-proof sheet impact the movable plate 231 downward. The movable plate 231 moves downward against the resistance of the first return spring 232 and is converted into a pulling force on the limit pin 237 through the flexible cable 235. When the pulling force overcomes the preload provided by the second return spring 233, the limit pin 237 is pulled out from the support position to release the limit on the support plate 236. Then, the support plate 236, driven by its own weight and / or a preset elastic element (such as a torsion spring), quickly flips downward around the hinge shaft 2361. The support plate 236 flips away from the auxiliary explosion-proof sheet 212b, and the bottom support of the auxiliary explosion-proof sheet 212b is removed. At this time, the auxiliary explosion-proof sheet 212b is only fixed by the auxiliary mounting base 211b pressing the auxiliary sealing ring, and its explosion resistance is significantly reduced, entering the "easily triggered" standby state. If the fault is not eliminated after the main pressure relief, the internal pressure will rise again, and the auxiliary explosion-proof sheet 212b will burst, opening the redundant pressure relief channel.

[0044] Furthermore, an auxiliary support frame 214b is fixed to the side of the auxiliary explosion-proof sheet 212b facing the auxiliary explosion-proof hole 111b; the auxiliary support frame 214b and the main support frame 214 have the same structure and installation method, which will not be described in detail here.

[0045] As a preferred embodiment, the limiting pin 237 is slidably disposed in the guide hole of the auxiliary mounting base 211b and is provided with a second return spring 233. The second return spring 233 provides a preload force to the limiting pin 237 toward the support position, ensuring that the limiting pin 237 can stably support the support plate 236 in the non-triggered state.

[0046] To more effectively transmit tension and change the direction of force, a guide pulley 234 is mounted on the rigid partition 227, and the flexible cable 235 passes around the guide pulley 234. In actual operation, the guide pulley 234 can also be mounted on the auxiliary mounting base 211b or the explosion-proof cover 22. The flexible cable 235 passes around the guide pulley 234 and then connects to the limiting pin 237. The introduction of the guide pulley 234 efficiently converts the downward pulling force of the movable plate 231 into a horizontal pulling force on the limiting pin 237 and reduces the frictional force when the flexible cable 235 moves.

[0047] In addition, a torsion spring (not shown in the figure) is coaxially sleeved on the hinge shaft 2361 of the support plate 236. One end of the torsion spring is fixed on the auxiliary mounting base 211b, and the other end acts on the support plate 236. Under normal conditions, the torsion spring is pre-tightened and stores elastic potential energy. When the limit pin 237 is pulled away, the torsion spring can provide the support plate 236 with a driving torque to make it flip downward, so that the support plate 236 flips downward quickly without relying on gravity, thus improving the reliability of operation.

[0048] The upper surface of the support plate 236 is provided with a buffer pad layer 2362. The buffer pad layer 2362 has a certain compressive deformation capacity and can adaptively fit, distributing the supporting effect of the support plate 236 to the entire supported area of ​​the auxiliary explosion-proof sheet 212b, avoiding excessive local pressure. Moreover, as a soft medium, the buffer pad layer 2362 can eliminate hard contact between the support plate 236 (usually a metal part) and the auxiliary explosion-proof sheet 212b (stainless steel sheet), protecting the integrity of the surface of the auxiliary explosion-proof sheet 212b.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A primary and secondary integrated pole-mounted circuit breaker, comprising a housing, and a disconnecting switch unit and a vacuum interrupter unit arranged in series within the housing; characterized in that, A main explosion-proof hole is provided on the bottom wall plate of the housing, and a main explosion-proof assembly is installed on the bottom wall plate below the main explosion-proof hole. An explosion-proof cover is fixed to the lower part of the bottom wall plate and covers the outside of the main explosion-proof assembly. The main explosion-proof assembly includes a main mounting base and a main explosion-proof sheet. The main mounting base is annular and fixedly connected to the bottom wall plate of the housing. The main explosion-proof sheet is located inside the main mounting base and faces the main explosion-proof hole. The periphery of the main explosion-proof sheet is pressed tightly by the main mounting base, and a main sealing ring is provided between the periphery of the main explosion-proof sheet and the bottom wall plate. The explosion-proof cover has a through opening.

2. The primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that, The inner periphery of the main mounting base is provided with a downwardly recessed support step, and the periphery of the main explosion-proof sheet overlaps on the support step.

3. The primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that, The main explosion-proof sheet is fixed with a main support frame on the side facing the main explosion-proof hole, and the main support frame has a hollow structure.

4. The primary and secondary integrated pole-mounted circuit breaker according to claim 3, characterized in that, The main support frame has an annular portion that is adapted to the shape of the main explosion-proof hole, and the orthographic projection of the annular portion is located within the inner contour range of the main mounting base; the main sealing ring is sleeved on the outer periphery of the annular portion.

5. The primary and secondary integrated pole-mounted circuit breaker according to claim 4, characterized in that, The annular portion is provided with an upwardly protruding positioning post, and the edge of the main explosion-proof hole is provided with a positioning groove for insertion into the positioning post.

6. The primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that, The periphery of the main explosion-proof sheet and the main sealing ring are pressed between the main mounting base and the bottom wall plate.

7. The primary and secondary integrated pole-mounted circuit breaker according to claim 6, characterized in that, The bottom wall plate is welded and fixed with a first fastening bolt. The main mounting base is provided with a first fastening hole for the first fastening bolt to pass through. The lower end of the first fastening bolt passes through the first fastening hole and is screwed with a first fastening nut.

8. The primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that, The bottom wall plate of the housing is welded and fixed with a second fastening bolt. The explosion-proof cover is provided with a fixing hole for the lower end of the second fastening bolt to pass through. The second fastening bolt is provided with a downward-facing stop surface, which abuts against the explosion-proof cover. After the lower end of the second fastening bolt passes through the fixing hole, a second fastening nut is screwed and fixed.

9. The primary and secondary integrated pole-mounted circuit breaker according to claim 1, characterized in that, The bottom wall plate is also provided with an auxiliary explosion-proof hole, and an auxiliary explosion-proof component is installed below the auxiliary explosion-proof hole and on the bottom wall plate of the shell. The auxiliary explosion-proof component is located inside the explosion-proof cover. The auxiliary explosion-proof component includes an auxiliary mounting base and an auxiliary explosion-proof sheet; the auxiliary mounting base is annularly fixedly connected to the bottom wall plate, and the auxiliary explosion-proof sheet is located on the inner side of the auxiliary mounting base and is directly opposite the auxiliary explosion-proof hole; the periphery of the auxiliary explosion-proof sheet is pressed by the auxiliary mounting base, and an auxiliary sealing ring is provided between the periphery of the auxiliary explosion-proof sheet and the bottom wall plate. The explosion-proof cover has a rigid partition inside, which isolates the spaces corresponding to the main explosion-proof sheet and the auxiliary explosion-proof sheet, forming a main pressure relief chamber and an auxiliary pressure relief chamber. It also includes a pressure coordination mechanism, which includes a movable plate disposed in the main pressure relief chamber, a support plate and a limiting pin disposed in the auxiliary pressure relief chamber, and a flexible cable connecting the movable plate and the limiting pin. The movable plate is located below the main explosion-proof sheet and is supported by the explosion-proof cover by the first reset spring; One end of the support plate is hinged to the auxiliary mounting base, and the other end is supported and limited by the limiting pin under normal conditions, so that the support plate maintains a horizontal support state to support the auxiliary explosion-proof sheet. One end of the flexible cable is fixed to the movable plate, and the other end passes through the rigid partition and is connected to the limiting pin. When the main explosion-proof sheet explodes, causing the movable plate to be compressed and moved downward, the flexible cable pulls the limiting pin away from the support position, so that the support plate flips under the action of gravity or elastic force, thereby removing the support for the auxiliary explosion-proof sheet.

10. The primary and secondary integrated pole-mounted circuit breaker according to claim 9, characterized in that, The limiting pin is slidably disposed in the guide hole of the auxiliary mounting base and is provided with a second return spring. The second return spring provides a preload force to the limiting pin toward the support position. The auxiliary mounting base or the rigid partition or explosion-proof cover is equipped with a guide pulley, and the flexible cable passes around the guide pulley. A torsion spring is provided on the hinge shaft between the support plate and the auxiliary mounting base to provide a downward flipping torque for the support plate.

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