Arc extinguishing chamber structure of circuit breaker or disconnecting switch

Abstract

The present invention relates to the technical field of low-voltage electrical devices. Disclosed is an arc extinguishing chamber structure of a circuit breaker or a disconnecting switch, which is who

Description

An arc extinguishing chamber structure of a circuit breaker or disconnector Technical Field

[0001] The present invention belongs to the technical field of low-voltage electrical equipment, and in particular relates to an arc extinguishing chamber structure of a circuit breaker or an isolating switch. Background Art

[0002] Circuit breakers and disconnectors are the most important electrical equipment in power distribution systems and new energy systems. As system voltage continues to increase, the performance requirements for circuit protection switches are also getting higher and higher. Miniaturization, high performance, modularization, and high reliability are the main development directions of air circuit breakers and disconnectors at this stage.

[0003] With the development of electric power, the operating voltage of the power system has been continuously improved, with AC voltage as high as AC1500V and DC voltage also increased to DC2500V. At the same time, since the DC system does not have a natural zero-crossing phenomenon relative to the AC system current, it cannot extinguish the arc at the moment when the AC current crosses zero like AC. It can only rely on rapid elongation and cooling of the arc to make the arc voltage exceed the power supply voltage, and then extinguish the arc. Therefore, arc extinguishing is more difficult. However, the miniaturization and high performance requirements of circuit breakers inevitably require that the space occupied by the arc extinguishing chamber structure becomes smaller and smaller, and the arc extinguishing capacity becomes higher and higher. It is difficult for existing arc extinguishing chambers to meet this requirement.

[0004] Summary of the Invention

[0005] The present invention provides an arc extinguishing chamber structure for a circuit breaker or disconnector. By means of overall plug-in assembly, as well as the thickness variation design and arrangement trend of the internal grid plates, the present invention solves the technical problem that the current arc extinguishing chamber does not meet the power system's demand for small-volume and high-performance manufacturing.

[0006] The present invention can be achieved through the following technical solutions:

[0007] An arc extinguishing chamber structure for a circuit breaker or disconnector is assembled as a whole using a plug-in structure. The internal grid plates are arranged in an undulating pattern. The changing curve formed on the bottom surface is designed to match the arc elongation process, and the thickness of each grid plate gradually decreases from thick to thin along the arc elongation direction.

[0008] Furthermore, an arc-striking slope is provided at the end of the moving contact in the circuit breaker, and the changing curved surface formed by the bottom surface of the grid is set to rise-horizontal-rise-horizontal.

[0009] Furthermore, the changing curved surface formed by the bottom surface of the grid is recorded as a first rising section, a first horizontal section, a second rising section and a second horizontal section. The holding point of the second horizontal section cooperates with the moving arc-striking piece on the moving contact side, the lowest point of the first rising section cooperates with the static arc-striking piece on the static contact side, and the highest point of the first rising section is consistent with the highest point of the movement trajectory of the arc-striking slope of the moving contact during the opening process.

[0010] Furthermore, the thickness variation of each grid piece along the direction in which the arc is stretched is provided with two or more gradients.

[0011] Furthermore, the individual gratings are arranged in a row at intervals to form a grating group, and the left and right sides of the grating group are respectively plugged into and assembled with their corresponding side panels. The tops of the grating group and the two side panels are jointly plugged into the recesses at the bottom of the cover, and the bottoms are plugged into the interior of the gas-producing component. The tops and bottoms of the side panels are respectively threadedly connected to the cover and the gas-producing component.

[0012] Furthermore, L-shaped notches are provided on both sides of the tops of the multiple grid plates in the middle of the grid plate group, which form a square recess with the side plates on the corresponding sides. A plug-in that matches it is provided inside each of the square recesses, and the three are fixed by bolts passing through the screw holes on the side walls of the cover, the side plates and the corresponding plug-in.

[0013] Furthermore, a protrusion is provided on the surface of each plug-in that contacts the side panel, and a U-shaped groove that matches the protrusion is provided at a position on each side panel corresponding to the protrusion to limit the front and rear position of the plug-in.

[0014] Furthermore, a plurality of square protrusions extending outward are provided on the left and right sides of each grid plate, and slots for the square protrusions to fit are provided at corresponding positions of each side plate.

[0015] Two extension legs are provided at the bottom of each grid plate. The extension legs at the same position are inserted into the same gas producing component. The cross section of the gas producing component is a U-shaped structure. The width of the internal cavity matches the width of the extension legs. The internal cavity is provided with slots that match each extension leg.

[0016] One side surface of the gas producing component is a gas producing surface, and the other side surface is a mounting surface. The mounting surface is inserted between the side plate and the grid sheet and is connected to the side plate through threads.

[0017] A method for assembling an arc extinguishing chamber structure of a circuit breaker or disconnector based on the above-mentioned method comprises inserting the square protrusions on one side of each grid into the corresponding slots of one of the side plates in turn, and then inserting the slots of the other side plates into the square protrusions on the other side of each grid plate to realize the plug-in assembly of the grid plate and the two side plates, and then assembling the two plug-ins from top to bottom into the corresponding square recesses, and then clamping the cover on the top of the grid plate and the side plate, and fixing the cover, side plate and plug-ins together with bolts, and finally inserting the two gas-generating parts into the corresponding extension feet of each grid plate from bottom to top, and fixing the gas-generating parts and the side plates together with bolts to complete the assembly of the entire arc extinguishing chamber.

[0018] The beneficial technical effects of the present invention are as follows:

[0019] 1. The arc extinguishing chamber structure of the present invention is assembled by plug-in assembly as a whole, minimizing the external installation space of each component and providing as much space as possible for the installation of internal grids to prepare for improving the arc extinguishing ability. At the same time, the thicker grids are concentrated near the arc generation point, and the thinner grids are concentrated in the area where the arc extinguishing is about to end, so as to maximize the acceleration of heat absorption and cooling of the arc. The arrangement trend of the grids is also made to match the changing trend of arc elongation, so as to accelerate the arc absorption speed, reduce arc leakage, and improve the arc extinguishing ability, thereby meeting the existing power system's demand for small-volume and high-performance manufacturing of arc extinguishing chambers.

[0020] 2. Taking into account the relative positional relationship between the moving contact, the moving arc-striking piece, the static arc-striking piece and the arc extinguishing chamber, the changing surface during the arc elongation process shows a rise-fall-rise-fall trend. Based on this, the grids are arranged so that the changing surface formed by their bottom surfaces is consistent with the above trend, corresponding to the entire arc elongation process, and the distance between the two is controlled to ensure that the arc can be quickly and completely sucked into the arc extinguishing chamber as much as possible, thereby accelerating the arc extinguishing.

[0021] 3. By relying on the added plug-in to act as a nut fixing, the cover and the side plate can be stably fixed together so that the two side plates can firmly clamp the grid therein without riveting. This can effectively avoid the risk of the grid tilting and becoming unstable due to the weakening of the riveting strength caused by the high temperature during the arc extinguishing process, thereby improving the reliability of the arc extinguishing chamber. At the same time, the gas-producing parts are assembled to the extension legs by plug-in and then fixed with bolts, which improves the assembly convenience of the gas-producing parts. The components of the entire arc extinguishing chamber are mainly plug-in and supplemented by threaded fixing. By cleverly combining the two, the space occupied by the arc extinguishing chamber shell can be effectively reduced, leaving as much internal space as possible for grid assembly. At the same time, the efficiency of assembly and maintenance can be improved, and the production and maintenance costs can be reduced.

[0022] 4. The arc extinguishing chamber structure of the present invention has strong versatility, good practicality, simple overall structure, and is easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic diagram of the overall structure of the present invention;

[0024] FIG2 is a schematic diagram of a changing curved surface of the bottom surface of the grid plate of the present invention;

[0025] FIG3 is a schematic diagram of the structure of the plug-in and the square recess of the present invention;

[0026] FIG4 is a schematic cross-sectional view of the overall structure of the present invention;

[0027] FIG5 is a schematic structural diagram of a gas generating member according to the present invention;

[0028] Among them, 1-grid, 2-side plate, 21-U-shaped groove, 3-cover, 4-plug-in, 41-bump, 5-gas-generating part, 51-gas-generating surface, 52-mounting surface. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0030] As shown in Figure 1, the present invention proposes an arc extinguishing chamber structure for a circuit breaker or disconnector. The structure is assembled as a whole using a plug-in structure. The internal grid plates 1 are arranged in an undulating pattern. The changing curve formed on their bottom surfaces matches the arc elongation process, and the thickness of each grid plate 1 gradually decreases from thick to thin along the arc elongation direction. In this way, the overall plug-in structure is assembled to minimize the installation space outside the components, providing as much space as possible for the installation of internal grid plates to prepare for improved arc extinguishing capability. At the same time, the thicker grid plates are concentrated near the arc generation point to maximize heat absorption and cool the arc. The arrangement of the grid plates is also aligned with the changing trend of arc elongation to accelerate arc absorption, reduce arc leakage, and improve arc extinguishing capability, thereby meeting the existing power system's demand for small-volume, high-performance arc extinguishing chambers.

[0031] The details are as follows:

[0032] Usually, the arc extinguishing chamber of a DC circuit breaker adopts a magnetic blowing method to extinguish the arc. Its moving contact is composed of a combination of multiple short contact pieces and long contact pieces. At the same time, an arc-striking slope is provided at the end of the long contact piece so that the arc can be quickly transferred to the arc-striking slope, so that the arc is stretched obliquely upward. At the same time, static arc-striking pieces and moving arc-striking pieces are provided on the side of the arc extinguishing chamber close to the static contact and the side of the moving contact, so as to introduce the arc into the arc extinguishing chamber for arc extinguishing. In this way, in the process of opening the moving and static contacts, the arc is stretched obliquely upward from the contact point between the static and moving contacts to the arc-striking slope of the moving contact, which is the first rising section. Driven by the operating mechanism, the moving contact rotates to move away from the static contact. At this time, the arc passes the highest point and begins to descend until the opening is completed, which is the first descending section. Then the arc transitions to the arc-striking slope. The moving arc-striking piece with the same slope is the second rising section. Finally, the arc is reversely led back to the arc extinguishing chamber through the moving arc-striking piece, and there will be a reverse rising trend, which is the second descending section. Therefore, the changing surface during the arc elongation process is recorded as A, which is mostly rising-falling-rising-falling. The changing surface formed by the bottom surface of the grid 1 at the corresponding position is recorded as B, and can also be set to rising-falling-rising-falling, so that the changing surfaces A and B have basically the same trend, and the head end of the first rising section is connected to the static arc-striking piece, and the tail end of the second descending section is connected to the moving arc-striking piece, and the distance between the two is limited at the same time, so as to ensure that the arc can be quickly sucked into the arc extinguishing chamber, and cooperate with the moving arc-striking piece and the static arc-striking piece to make the starting end and the ending end of the arc both introduced into the arc extinguishing chamber, reducing arc leakage.

[0033] As shown in Figure 2, while ensuring that the spacing between the changing surfaces A and B is relatively stable, considering that the end of the moving contact mostly moves along a circular trajectory, when the opening starts, that is, the moving and static contacts are at the just-opening position, the end of the moving contact may not be at the highest point of its circular trajectory, but the arc will still first transition to the end of the moving contact and then move along the circular trajectory. Therefore, the highest point of the first rising section can extend to the highest point of the circular trajectory. At the same time, the opening stroke is relatively small, and the circular motion trajectory of the end of the moving contact can be approximated as a straight line, that is, the first descending section can be replaced by the first horizontal section, and in order to transition the arc from the arc-starting inclined surface of the moving contact to the moving arc-starting plate, the slopes of the two need to be designed to be consistent. Therefore, the second descending section can also be replaced by the second horizontal section. In this way, when the trend of the changing surface B is closer to the trend of the changing surface A, the arc extinguishing ability can be guaranteed, the complexity of the grid arrangement can be simplified, and the manufacturing cost can be further reduced.

[0034] In order to further improve the arc extinguishing ability, the thickness of each grid 1 gradually decreases from thick to thin along the direction of arc elongation. At the beginning of arc extinguishing, the energy contained in the arc is very large. With the help of thick grid 1, this energy can be absorbed as quickly as possible and converted into heat energy. As the arc is elongated, the energy it contains gradually weakens. Therefore, the closer to the end of arc extinguishing, the thickness of grid 1 can gradually become smaller. This setting is more in line with the energy change trend of the arc than the conventional equal thickness setting, and is more conducive to concentrating the advantage to absorb the energy in the initial stage of the arc and accelerate arc extinguishing.

[0035] Taking into account the practical feasibility of manufacturing, the thickness variation of the grid plate 1 can be set to have multiple gradients, preferably two gradients or three gradients.

[0036] In order to provide more space for the installation of the grid 1, it is necessary to minimize the space occupied by the shell in the arc extinguishing chamber. Therefore, we design a plug-in structure to realize the assembly of various components. First, each grid 1 is evenly spaced and plugged into the two side plates 2 by plugging. A plurality of outwardly extending square protrusions can be provided on the left and right sides of each grid 1, such as two. A slot that cooperates with the square protrusion is provided at a corresponding position of each side plate 2. The plug-in is realized by the cooperation between the square protrusion and the slot.

[0037] Then assemble the cover 3. Considering that the total mass of the grid group formed by arranging multiple grid plates 1 is large, and the thickness of the side plate 2 is small, it is not suitable as a locking threaded hole. Therefore, we add a plug-in 4 between the side plate 2 and the grid group 1. As shown in Figure 3, both sides of the top of the multiple grid plates in the middle of the grid group can be designed with L-shaped notches, which can form a square recess with the side plate 2 on the corresponding side. The inner cavity of these two square recesses cooperates with the plug-in 4, and then the three are fixed by means of bolts passing through the screw holes on the side wall of the cover, the side plate and the corresponding plug-in 4. Considering the convenience of assembly, the width of the square recess can be matched with the width of the plug-in 4 to limit the position of the plug-in 4 in the left and right directions. The plug-in 4 is positioned so that it can be fixed to the inner recess of the square body. At the same time, a protrusion 41 is provided on the side of each plug-in 4 that contacts the side plate 2, and a U-shaped groove 21 is provided on each side plate 2 at the position corresponding to the protrusion 41. In this way, the plug-in 4 can be assembled into the inner recess of the square body by placing the protrusion into the U-shaped groove 21 and pressing the plug-in 4 from top to bottom. The cooperation between the protrusion 41 and the U-shaped groove 21 can also define the front and rear position of the plug-in 4. In this way, through multi-directional fixation, the cover 3 and the side plate 2 can be stably fixed together, thus eliminating the need for riveting and achieving complete fixation of multiple grids 1. This can effectively avoid the risk of grid tilting and instability caused by the high temperature during the arc extinguishing process due to the weakening of the riveting strength, thereby improving the reliability of the arc extinguishing chamber. In addition, the plug-in 4 can be integrated with the cover 3 or pre-assembled inside the cover 3 to enhance the fit and tightness between the cover 3, the side plate 2 and the grid group.

[0038] In order to facilitate the assembly of the gas-producing parts 5, as shown in Figures 1, 4, and 5, the cross-section of each gas-producing part 5 is a U-shaped structure, the width of the internal cavity matches the width of the extension foot, and a slot that matches the extension foot of each grid plate 1 is provided in the internal cavity. One of the side surfaces of the gas-producing part 5 is a gas-producing surface 51, and the other side surface is a mounting surface 52. The gas-producing part 5 is inserted from bottom to top into the extension foot on the corresponding side, so that the extension foot on the same side is assembled together into the slot inside the same gas-producing part 5, and its mounting surface 52 is inserted between the side plate 2 and the grid plate 1, and can be connected to the side plate 2 by bolts.

[0039] The present invention also provides an assembly method for the arc extinguishing chamber structure of the circuit breaker or disconnector described above, wherein the square protrusions on one side of each grid plate are sequentially inserted into the corresponding slots of one of the side plates, and then the slots of the other side plate are inserted into the square protrusions on the other side of each grid plate to achieve plug-in assembly of the grid plate and the two side plates. The protrusions of the two plug-ins are then aligned with the U-shaped slots, and the plug-ins are pressed from top to bottom to assemble them into the corresponding square recesses. The cover is then clamped on the top of the grid plate and the side plate to define the front-back, left-right, and up-down positions of the grid plate and the side plate, and the cover, side plate, and plug-in are fixed together with bolts to achieve stable assembly.

[0040] Finally, insert the two gas-generating parts into the corresponding extension legs of each grid from bottom to top, and use bolts to fix the gas-generating parts and side plates together to complete the assembly of the entire arc extinguishing chamber. When the gas-generating parts are damaged, just remove the bolts and the gas-generating parts can be pulled out and replaced.

[0041] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is limited by the appended claims.

Claims

1. An arc extinguishing chamber structure of a circuit breaker or a disconnector, characterized in that: The whole is assembled with a plug-in structure, and the internal grid plates are arranged in undulating shapes. The changing curved surface formed on the bottom surface is designed to match the arc elongation process, and the thickness of each grid plate gradually decreases along the arc elongation direction.

2. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 1, characterized in that: The end of the moving contact in the circuit breaker is provided with an arc-striking inclined surface, and the changing curved surface formed by the bottom surface of the grid is set to rise-horizontal-rise-horizontal.

3. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 2, characterized in that: The changing curved surface formed by the bottom surface of the grid is recorded as a first rising section, a first horizontal section, a second rising section and a second horizontal section. The holding point of the second horizontal section cooperates with the moving arc-striking piece on the moving contact side, the lowest point of the first rising section cooperates with the static arc-striking piece on the static contact side, and the highest point of the first rising section is consistent with the highest point of the movement trajectory of the arc-striking slope of the moving contact during the opening process.

4. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 1, characterized in that: The thickness variation of each grid sheet along the direction in which the arc is stretched is arranged to have two or more gradients.

5. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 1, characterized in that: The grid plates are arranged in a row at intervals to form a grid plate group. The left and right sides of the grid plate group are respectively plugged and assembled with the corresponding side plates. The grid plate group and the tops of the two side plates are jointly plugged into the recesses at the bottom of the cover, and the bottoms are plugged into the interior of the gas-producing part. The tops and bottoms of the side plates are respectively connected to the cover and the gas-producing part with corresponding threads.

6. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 5, characterized in that: L-shaped notches are provided on both sides of the tops of the multiple grid plates in the middle of the grid plate group, which form a square recess with the side plates on the corresponding sides. A plug-in matching it is provided inside each of the square recesses, and the three are fixed by bolts passing through the screw holes on the side wall of the cover, the side plate and the corresponding plug-in.

7. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 6, characterized in that: A protrusion is arranged on one surface of each plug-in unit that contacts the side plate, and a U-shaped groove matching with the protrusion is arranged at a position of each side plate corresponding to the protrusion to limit the front and rear position of the plug-in unit.

8. The arc extinguishing chamber structure of a circuit breaker or disconnector according to claim 5, characterized in that: A plurality of square protrusions extending outward are arranged on the left and right sides of each grid plate, and a slot hole matching the square protrusion is arranged at a corresponding position of each side plate. Two extension pins are arranged at the bottom of each grid plate, and the extension pins at the same position are inserted into the same gas producing part together. The cross section of the gas producing part is a U-shaped structure, the width of the internal cavity matches the width of the extension pins, and the internal cavity is provided with slots matching each extension pin. One side surface of the gas producing component is a gas producing surface, and the other side surface is a mounting surface. The mounting surface is inserted between the side plate and the grid sheet and is connected to the side plate through threads.

9. An assembly method of an arc extinguishing chamber structure of a circuit breaker or disconnector according to any one of claims 1 to 8, characterized in that: Insert the square protrusion on one side of each grid into the corresponding slot of one of the side panels in turn, and then insert the slot of the other side panel into the square protrusion on the other side of each grid to realize the plug-in assembly of the grid and the two side panels. Then assemble the two plug-ins from top to bottom into the corresponding square recesses, and then clamp the cover on the top of the grid and the side panel, and fix the cover, side panel and plug-in together with bolts. Finally, insert the two gas-producing parts from bottom to top into the corresponding extension feet of each grid, and fix the gas-producing parts and the side panel together with bolts to complete the assembly of the entire arc extinguishing chamber.

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