Arc extinguishing device for ring main unit

Abstract

The utility model discloses an arc extinguishing device for a ring main unit, which comprises a connecting bottom plate, one end of the upper surface of the connecting bottom plate is provided with a pair of ceramic boxes, cushion blocks are arranged between the ceramic boxes and the connecting bottom plate, and a plurality of arc extinguishing grid sheets are arranged between the pair of ceramic boxes at equal intervals; diffusion through grooves are formed in the arc extinguishing grid pieces and are of an inverted-T-shaped structure, weakening holes are symmetrically formed in the arc extinguishing grid pieces with the diffusion through grooves as the center, the interior of the ceramic box is of a hollow structure, the outer side wall of the cavity is higher than the inner side wall of the cavity, a plurality of installation grooves are formed in the outer side wall of the cavity, and the arc extinguishing grid pieces are arranged in the cavity. And the side walls of the arc extinguishing grid sheets are connected with the mounting grooves. According to the arc extinguishing grid plate, conventional grooves in an existing arc extinguishing grid plate are improved into the convex diffusion through grooves, the arc extinguishing grid plate forms a special-shaped grid plate through the diffusion through grooves, the special-shaped design can better guide an electric arc to move along a preset path, the path length of the electric arc is increased, and therefore the dispersing and cooling effects of the electric arc are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of arc extinguishing for electrical cabinets, and specifically relates to an arc extinguishing device for a ring main unit. Background Art

[0002] When the electrical components in the ring main unit are separated under the condition of carrying current, an arc will be generated. Especially when breaking a large short-circuit current, the energy of the arc is large, and the ablation of the contact is serious. Therefore, in a low-voltage circuit breaker, an arc extinguishing chamber is usually set up to extinguish the arc. The arc extinguishing chamber is generally assembled by an arc extinguishing grid plate group and an insulating clamping plate. The arc extinguishing grid plate group is formed by arranging a plurality of arc extinguishing grid plates made of ferromagnetic materials at intervals. After the arc enters the arc extinguishing grid plates, it will be divided into many series-connected short arcs, and each short arc has a near-pole voltage drop.

[0003] Chinese Patent CN218585913U discloses an arc extinguishing grid plate group of a circuit breaker. In this application, at least one grid plate is a special-shaped grid plate, and a concave notch is provided on the edge of the outlet end side of the base of the special-shaped grid plate. When in use, when the opened arc enters the arc extinguishing grid plate group, the short arc formed between the grid plates is subjected to the Lorentz force in the direction of the notch on the special-shaped grid plate, so that the arc moves towards one end in the direction of the notch, making it easier for the arc to stay inside the grid plates and not stay at the arc inlet end position of the grid plates for a long time, which is beneficial to the cutting of the arc and improves the breaking capacity of the circuit breaker.

[0004] It can be seen from this that in the prior art, in order to make the arc extinguishing grid plates have a better arc extinguishing effect, a notch with a special-shaped structure is usually opened on the arc extinguishing grid plates, so that when the arc enters the arc extinguishing grid plates, it can stay inside the grid plates better under the influence of the Lorentz force, which is beneficial to segmentation. However, the arc has a high temperature, which will cause the grid plates to heat up quickly. Since the arc extinguishing grid plates are usually made of insulating materials, when the temperature rises, its insulating ability will decline, resulting in the arc being more likely to pass through the partition plate, reducing the effective cooling and dispersion of the arc. In addition, the aggregation of high temperature is also likely to cause the material degradation of the arc extinguishing grid plates, affecting the service life of the arc extinguishing grid. Summary of the Utility Model

[0005] The purpose of this part is to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract of the specification and the title of the utility model of this application, to avoid obscuring the purpose of this part, the abstract of the specification, and the title of the utility model. However, such simplifications or omissions cannot be used to limit the scope of the utility model.

[0006] To solve the problems raised in the above background art, the utility model adopts the following technical solutions.

[0007] An arc extinguishing device for a ring main unit, comprising a connecting base plate. At one end of the upper surface of the connecting base plate, a pair of ceramic boxes are installed. There are cushion blocks between the ceramic boxes and the connecting base plate. A plurality of arc extinguishing grid sheets are arranged at equal intervals between the pair of ceramic boxes. Diffusion through slots are formed in the arc extinguishing grid sheets, and the diffusion through slots are in a convex-shaped structure. Weakening holes are symmetrically formed in the arc extinguishing grid sheets with the diffusion through slots as the center. The interior of the ceramic box is a hollow structure, and the outer side wall of the cavity is higher than its inner side wall. A plurality of installation slots are formed in the outer side wall of the cavity. The arc extinguishing grid sheets are placed in the cavity, and the side walls of the arc extinguishing grid sheets are connected to the installation slots.

[0008] Preferably, a plurality of partition plates are provided in the cavity of the ceramic box, and the partition plates divide the arc extinguishing grid sheets placed in the cavity into multiple groups; the slot widths of the plurality of installation slots are different from each other.

[0009] Preferably, a notch is formed at the upper end of the outer side wall of the cavity. The notch communicates with the end of the installation slot, and clamping blocks are integrally connected to both sides of the upper end of the arc extinguishing grid sheet. The clamping blocks are clamped in the notch, and the upper surface of the clamping blocks is flush with the end face of the notch.

[0010] Preferably, feet are integrally provided on both sides of the lower end of the arc extinguishing grid sheet. When the arc extinguishing grid sheet is inserted into the installation slot, its feet abut against the inner wall of the installation slot.

[0011] Preferably, the weakening holes are integrally in a hollowed-out shape; the weakening holes are composed of a plurality of arc-shaped through holes, and there are multiple circles of arc-shaped through holes. The arc-shaped through holes in the same circle form a circular through hole-shaped structure.

[0012] Preferably, a knife switch is rotatably connected to one end of the upper surface of the connecting base plate by a pin seat, and a contact is provided at the other end of the upper surface of the connecting base plate. The knife switch and the contact are on the same straight line, and the knife switch is directly below the protruding end of the diffusion through slot.

[0013] Preferably, the ceramic box and the arc extinguishing grid sheets together form an arc extinguishing grid, and the arc extinguishing grid is placed in the vacuum chamber of the ring main unit.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] (1) In the present application, the conventional slots on the existing arc extinguishing grid sheets are improved into convex-shaped diffusion through slots. Through the diffusion through slots, the arc extinguishing grid sheets form special-shaped grid sheets. The special-shaped design can better guide the arc to move along a predetermined path, increasing the path length of the arc, thereby improving the dispersion and cooling effect of the arc. Through the special shape design, the special-shaped arc extinguishing grid sheets can provide more contact areas during the movement of the arc, which can improve the distribution and transfer of heat, help reduce the temperature of the arc extinguishing grid sheets, and can convert the arc energy into heat energy and dissipate it more quickly.

[0016] (2) The present application also symmetrically provides weakening holes on the arc extinguishing grid plates. The weakening holes are circular hollow structures. The airflow introduced through the hollow weakening holes can directly cool the arc path, promote the flow of the surrounding air, increase the convective heat dissipation effect, improve the cooling speed of the arc, help quickly take away the heat generated by the arc, and thus reduce the temperature of the arc extinguishing grid plates; effective cooling can reduce the thermal stress caused by high temperature, extend the service life of the arc extinguishing grid plates, and reduce the risk of structural damage caused by thermal expansion.

[0017] (3) At the same time, the existence of the hollow weakening holes may change the movement trajectory of the arc, making it more difficult for the arc to penetrate the grid plates, thereby enhancing the dispersion effect of the arc. Without affecting the structural strength and function, the hollow weakening holes formed by removing some materials can reduce the material usage to a certain extent. The hollow weakening holes can reduce the weight of the arc extinguishing grid plates, which helps to achieve the miniaturization and lightweight of the equipment.

[0018] (4) In the present application, using a ceramic box as the outer shell of the arc extinguishing grid plates has a very high resistivity, can provide excellent insulation protection, prevent the arc from penetrating or bypassing the arc extinguishing grid, can maintain its physical and chemical stability in a high-temperature environment, is not prone to thermal expansion or deformation, and is suitable for use under extreme conditions where high-energy arcs are generated. Generally, ceramic materials have good chemical stability, can resist the erosion of harmful gases and particles generated by the arc, extend the service life, and have relatively high hardness and strength, can withstand the mechanical stress during switch operation, and are not easily damaged. Description of the Drawings

[0019] Figure 1 is the three-dimensional structure of the arc extinguishing device in the present utility model Figure 1 .

[0020] Figure 2 is the three-dimensional structure of the arc extinguishing device in the present utility model Figure 2 .

[0021] Figure 3 is the disassembled structure diagram of the arc extinguishing device in the present utility model.

[0022] Figure 4 is the assembly schematic diagram of the arc extinguishing device in the present utility model.

[0023] Figure 5 is the assembly schematic cross-sectional view of the arc extinguishing device in the present utility model.

[0024] Figure 6 is the structure diagram of the arc extinguishing grid plates in the present utility model.

[0025] The corresponding relationship between the labels of each figure and the component names in the figure is as follows:

[0026] 100, Connecting base plate; 101, Knife switch; 102, Contact; 103, Ceramic box; 1031, Installation groove; 1032, Partition; 1033, Spacer; 104, Arc extinguishing grid; 1041, Diffusion through slot; 1042, Weakening hole; 1043, Foot; 1044, Block. Detailed implementation mode

[0027] In order to make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific implementation mode of the present utility model will be given in conjunction with the accompanying drawings of the specification.

[0028] In the following description, many specific details are set forth in order to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0029] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation mode of the present utility model. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments. The present utility model provides the following embodiments.

[0030] Figure 1 and Figure 2 The arc extinguishing device for the ring main unit in this embodiment. The arc extinguishing device in this embodiment includes a connecting base plate 100. One end of the upper surface of the connecting base plate 100 is provided with a pair of ceramic boxes 103. A plurality of arc extinguishing grids 104 are arranged at equal intervals between the pair of ceramic boxes 103. The ceramic boxes 103 and the arc extinguishing grids 104 together form an arc extinguishing grid, and the arc extinguishing grid is placed in the vacuum chamber of the ring main unit. Among them, the arc extinguishing grids 104 are usually made of conductive materials such as copper or aluminum and are designed with multiple gaps. These gaps are normally closed, but when the circuit needs to be disconnected, they can be quickly opened by mechanical or electromagnetic force to form a sufficient gap to cut off the current. When current passes through these gaps, due to the ionization and thermal effect of the gas, an arc will be generated. The design of the arc extinguishing grid should be able to quickly cool the arc and make it extinguish. The ceramic box 103 has a very high resistivity, can provide excellent insulation protection, prevent the arc from penetrating or bypassing the arc extinguishing grids 104, and can maintain its physical and chemical stability in a high-temperature environment, and is not prone to thermal expansion or deformation. The connecting base plate 100, as a basic component, is used to provide installation points for other components. And usually the materials of the connecting base plate 100 and the ceramic box 103 are different. Therefore, in order to insulate and delay heat transfer, a spacer 1033 is provided between the ceramic box 103 and the connecting base plate 100 in this application.

[0031] Figure 6 This is the structure diagram of the arc extinguishing grid sheet 104 in this embodiment. In this embodiment, a diffusion through slot 1041 is provided on the arc extinguishing grid sheet 104. The diffusion through slot 1041 has a convex shape. Through the diffusion through slot 1041, the arc extinguishing grid sheet 104 forms a special-shaped grid sheet. The special-shaped design can better guide the arc to move along a predetermined path, increasing the path length of the arc, thereby improving the dispersion and cooling effect of the arc. Weakening holes 1042 are symmetrically provided on the arc extinguishing grid sheet 104 with the diffusion through slot 1041 as the center. The weakening holes 1042 are overall in a hollow shape; the weakening holes 1042 are composed of multiple arc-shaped through holes, and there are multiple circles of arc-shaped through holes. The arc-shaped through holes in the same circle form a circular through hole-shaped structure. The weakening holes 1042 are in a circular hollow shape. The air flow introduced through the hollow-shaped weakening holes 1042 can directly cool the arc path, promote the flow of the surrounding air, increase the convective heat dissipation effect, improve the cooling speed of the arc, help quickly take away the heat generated by the arc, thereby reducing the temperature of the arc extinguishing grid sheet 104; effective cooling can reduce the thermal stress caused by high temperature and extend the service life of the arc extinguishing grid sheet 104.

[0032] Figure 3 and Figure 4 This is the exploded view of the arc extinguishing device in this embodiment. The interior of the ceramic box 103 in this embodiment is a hollow structure, which is convenient for placing the arc extinguishing grid sheet 104. And the hollow design can also avoid heat accumulation to a certain extent. Further, in order to enable the ceramic box 103 to better fix the arc extinguishing grid sheet 104, in this embodiment, the outer side wall of the cavity of the ceramic box 103 is higher than its inner side wall, so as to use the higher outer side wall to constrain the arc extinguishing grid sheet 104, so that the arc extinguishing grid sheet 104 is fixed in the ceramic box 103. At the same time, in order to further strengthen the connection stability between the outer side wall of the ceramic box 103 and the arc extinguishing grid sheet 104, in this embodiment, multiple installation slots 1031 are provided on the outer side wall of the cavity. The arc extinguishing grid sheet 104 is placed in the cavity, and the side wall of the arc extinguishing grid sheet 104 is connected to the installation slots 1031. The arc extinguishing grid sheet 104 is inserted into the installation slots 1031, so that the arc extinguishing grid sheet 104 is fixed and constrained.

[0033] Refer to Figure 5In the present application, a plurality of partitions 1032 are provided in the cavity of the ceramic box 103. The partitions 1032 divide the arc-extinguishing grids 104 placed in the cavity into a plurality of groups. The plurality of arc-extinguishing grids 104 divide the arc into a plurality of paths, so that the arc is weakened and extinguished. Furthermore, in order to optimize the control and extinguishing performance of the arc, the present application designs the slot widths of the plurality of mounting grooves 1031 to be of different widths, and inserts a plurality of arc-extinguishing grids 104 into the mounting grooves 1031 with a larger width, so that the arc-extinguishing grids 104 fit together. The purpose of this design is that the arc-extinguishing grids 104 arranged separately can guide the arc to move along a specific path, increase the path length of the arc, and thus improve the dispersion and cooling effect of the arc, and the arc-extinguishing grids 104 fitted together may restrict the movement of the arc at certain stages, and help the arc to extinguish faster.

[0034] Furthermore, in order to ensure that the arc-extinguishing grid 104 is better connected and fixed to the ceramic box 103, the present application provides a notch at the upper end of the outer wall of the cavity of the ceramic box 103, the notch is connected to the end of the mounting groove 1031, and the upper ends of the arc-extinguishing grid 104 are integrally connected with clamping blocks 1044 on both sides, the clamping blocks 1044 are clamped in the notch, the upper surface of the clamping blocks 1044 is flush with the end face of the notch, and the fixation of the arc-extinguishing grid 104 is strengthened by the engagement of the clamping blocks 1044 with the notch.

[0035] At the same time, while ensuring that the arc-extinguishing grid 104 can be fixed relatively stably, the contact between the arc-extinguishing grid 104 and the ceramic box 103 is reduced as much as possible, thereby weakening the heat transfer to the ceramic box 103. The present application provides top feet 1043 on both sides of the lower end of the arc-extinguishing grid 104. When the arc-extinguishing grid 104 is inserted into the mounting groove 1031, its top feet 1043 abut against the inner wall of the mounting groove 1031.

[0036] See also Figure 1 and Figure 2 For the sake of a brief and intuitive explanation, the arc extinguishing device in the present application works as follows: a knife 101 is rotatably connected to one end of the upper surface of the connecting base plate 100 by a pin seat, and a contact 102 is provided at the other end of the upper surface of the connecting base plate 100, and the knife 101 and the contact 102 are on the same straight line, and the knife 101 is located directly below the protruding end of the diffusion groove 1041, wherein the knife 101 and the contact 102 represent the switch of the line, the purpose is to better disclose the working process of the arc extinguishing device in the present application, but the knife 101 and the contact 102 are not limited to the structure and installation method in the present application, and the components in the ring network cabinet that play the same role as the knife 101 and the contact 102 in the present application can replace the knife 101 and the contact 102.

[0037] The above content further elaborates on the present utility model in combination with specific embodiments. It cannot be determined that the specific implementation of the present utility model is only limited to these descriptions. For those of ordinary skill in the technical field to which the present utility model pertains, without departing from the concept of the present utility model, several simple deductions or substitutions can still be made, and all should be regarded as falling within the protection scope determined by the claims submitted for the present utility model.

Claims

1. An arc extinguishing device for a ring main unit, comprising a connecting base plate (100), a pair of ceramic boxes (103) being mounted on one end of the upper surface of the connecting base plate (100), a cushion block (1033) being arranged between the ceramic box (103) and the connecting base plate (100), a plurality of arc extinguishing grids (104) being arranged at equal intervals between the pair of ceramic boxes (103), Features: The arc extinguishing grid (104) is provided with a diffusion groove (1041), the diffusion groove (1041) is in a convex structure, weakening holes (1042) are symmetrically provided on the arc extinguishing grid (104) with the diffusion groove (1041) as the center, the interior of the ceramic box (103) is a hollow structure, and the outer wall of the cavity is higher than the inner wall thereof, a plurality of mounting grooves (1031) are provided on the outer wall of the cavity, the arc extinguishing grid (104) is placed in the cavity, and the side wall of the arc extinguishing grid (104) is connected to the mounting groove (1031).

2. The arc extinguishing device for a ring main unit according to claim 1, characterized in that: A plurality of partitions (1032) are arranged in the cavity of the ceramic box (103), and the partitions (1032) divide the arc-extinguishing grids (104) arranged in the cavity into a plurality of groups; the groove widths of the plurality of installation grooves (1031) are different from each other.

3. The arc extinguishing device for a ring main unit according to claim 2, characterized in that: A notch is provided at the upper end of the outer wall of the cavity, the notch is in communication with the end of the mounting groove (1031), and clamping blocks (1044) are integrally connected to both sides of the upper end of the arc extinguishing grid (104), the clamping blocks (1044) are clamped in the notch, and the upper surface of the clamping block (1044) is flush with the end surface of the notch.

4. The arc extinguishing device for a ring main unit according to claim 3, characterized in that: Top feet (1043) are integrally provided on both sides of the lower end of the arc-extinguishing grid (104); when the arc-extinguishing grid (104) is inserted into the installation groove (1031), the top feet (1043) abut against the inner wall of the installation groove (1031).

5. The arc extinguishing device for a ring main unit according to claim 4, characterized in that: The weakening hole (1042) is hollow as a whole; the weakening hole (1042) is composed of a plurality of arc-shaped through holes, and the arc-shaped through holes are provided with a plurality of circles, and the arc-shaped through holes in the same circle form a circular through hole structure.

6. The arc extinguishing device for a ring main unit according to claim 1, characterized in that: A knife gate (101) is rotatably connected to one end of the upper surface of the connecting base plate (100) by means of a pin seat, and a contact point (102) is provided at the other end of the upper surface of the connecting base plate (100). The knife gate (101) and the contact point (102) are on the same straight line, and the knife gate (101) is located directly below the protruding end of the diffusion slot (1041).

7. The arc extinguishing device for a ring main unit according to claim 1, characterized in that: The ceramic box (103) and the arc extinguishing grid piece (104) together form an arc extinguishing grid, and the arc extinguishing grid is placed in the vacuum chamber of the ring main unit.

Images