Contact arc extinguishing device for a switch

Abstract

The application relates to a contact arc extinguishing device of a switch, belonging to the technical field of low-voltage electrical appliances. The device comprises an arc extinguishing chamber and a contact system, the contact system comprises a moving contact and a static contact, the arc extinguishing chamber is located on one side of the opening direction of the contact system, the arc extinguishing chamber comprises a moving arc leading piece, the contact piece of the moving contact comprises a group of long contact pieces with at least one long contact piece, two groups of short contact pieces located on the two sides of the group of long contact pieces, the moving arc leading piece comprises a middle arc leading part matched with the long contact piece and two lateral arc leading parts matched with the two groups of short contact pieces, and the width of the middle arc leading part is less than or equal to the sum of the widths of the two lateral arc leading parts. The device has the advantages that when an arc is generated on the long contact piece, the arc can smoothly enter the arc extinguishing chamber, and when an arc is generated on the short contact piece, the arc can also smoothly enter the arc extinguishing chamber.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical technology, specifically relating to an arc-extinguishing device for the contacts of a switch. Background Technology

[0002] Switches are crucial electrical appliances in power supply and distribution lines. They interrupt the current carrying the circuit, protecting the lines and electrical equipment. A switch typically includes a contact system, which consists of moving and stationary contacts. When the moving contact actuates, it contacts or separates from the stationary contact, thus enabling the switch to conduct or disconnect. As is known in the industry, when a switch breaks, an electric arc is generated between the moving and stationary contacts. Due to the relatively large energy of the arc, it poses a significant challenge to breaking the switch. Therefore, switches usually include an arc-extinguishing chamber to extinguish the arc generated when the moving and stationary contacts separate. Only when the arc is extinguished is the circuit broken. The role of the arc-extinguishing chamber in ensuring the safe operation of electrical equipment is undeniable.

[0003] In the prior art, the moving contact includes a long contact piece and a short contact piece. The existing arc-inducing piece only cooperates with the long contact piece. However, in the actual switching process, an electric arc often appears on the short contact piece. At this time, how to quickly introduce the arc into the arc-extinguishing chamber has become a problem of concern in the industry. Utility Model Content

[0004] The purpose of this utility model is to provide a contact arc-extinguishing device for a switch. It provides a central arc-extinguishing part that cooperates with a long contact and a lateral arc-extinguishing part that cooperates with a short contact on the moving arc-extinguishing plate. The width of the central arc-extinguishing part 133 is less than or equal to the sum of the widths of the two lateral arc-extinguishing parts 134. This ensures that the arc generated on the long contact can smoothly enter the arc-extinguishing chamber, while also ensuring that the arc generated on the short contact can smoothly enter the arc-extinguishing chamber.

[0005] The purpose of this utility model is achieved as follows: a contact arc-extinguishing device for a switch includes an arc-extinguishing chamber and a contact system. The contact system includes a moving contact and a stationary contact. The arc-extinguishing chamber is located on one side of the contact system in the opening direction. The arc-extinguishing chamber includes a moving arc-inducing plate. The moving contact includes a set of long contact plates with at least one long contact plate and two sets of short contact plates located on both sides of the set of long contact plates. The moving arc-inducing plate includes a central arc-inducing portion that cooperates with the long contact plates and two lateral arc-inducing portions that cooperate with the two sets of short contact plates. The width of the central arc-inducing portion is less than or equal to the sum of the widths of the two lateral arc-inducing portions.

[0006] In a specific embodiment of this utility model, the width of the central arc-drawing portion is greater than or equal to the width of a set of long contact pieces, and less than or equal to 2.5 times the width of a set of long contact pieces.

[0007] In another specific embodiment of this utility model, the widths of the two lateral arc-drawing portions are equal, and the width of the central arc-drawing portion is twice the width of the lateral arc-drawing portions.

[0008] In another specific embodiment of this utility model, both the central arc-drawing portion and the lateral arc-drawing portion are flat.

[0009] In a further specific embodiment of this utility model, both the central arc-drawing portion and the lateral arc-drawing portion are V-shaped. Both the central arc-drawing portion and the lateral arc-drawing portion bend towards the inside of the arc-extinguishing chamber and then bend towards the outside of the arc-extinguishing chamber.

[0010] In a further specific embodiment of this utility model, the arc-extinguishing chamber includes a pair of side plates and a plurality of grid plates disposed between the pair of side plates, the plurality of grid plates being spaced apart from each other; the moving arc-inducing plate further includes a first part and a second part, the first part being located outside the grid plate array direction, the first part being parallel to and spaced apart from a nearby grid plate, the second part being located below the first part and bending inward toward the interior of the arc-extinguishing chamber, the central arc-inducing part being bent inward toward the interior of the arc-extinguishing chamber from the internal notch in the middle of the second part, and the lateral arc-inducing part being bent inward toward the interior of the arc-extinguishing chamber from the lower edge of the second part.

[0011] In another specific embodiment of this utility model, the gap formed between the central arc-drawing portion and the lateral arc-drawing portion is such that when the moving contact rotates to a position directly opposite the central arc-drawing portion, the distance between the long contact piece and the central arc-drawing portion is less than the width of the gap.

[0012] In yet another specific embodiment of this utility model, a clearance notch is provided on the outer side of the lateral arc-drawing portion.

[0013] In a further specific embodiment of the present invention, the arc-extinguishing chamber further includes a pair of gas-generating elements, which are respectively located at the lower edge of the grid plate and respectively wrap around a pair of grid plate legs of the grid plate.

[0014] In a further specific embodiment of this utility model, the gas generating component further includes a covering portion and an inclined portion. The covering portion extends from one end of the arc-extinguishing chamber corresponding to the stationary contact toward the moving contact. The inclined portion is located on the inner side of the covering portion and on the side of the covering portion away from the stationary contact. The central arc-inducing portion and the inclined portion are staggered.

[0015] Because this utility model adopts the above-mentioned structure, a central arc-inducing part that cooperates with the long contact piece and a lateral arc-inducing part that cooperates with the short contact piece are provided on the moving arc-inducing piece. The width of the central arc-inducing part is less than or equal to the sum of the widths of the two lateral arc-inducing parts. Thus, while ensuring that the electric arc generated on the long contact piece can smoothly enter the arc-extinguishing chamber, the electric arc generated on the short contact piece can also smoothly enter the arc-extinguishing chamber. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the switch described in this utility model; Figure 2 This is a three-dimensional schematic diagram of the moving contact and the arc-extinguishing chamber described in this utility model; Figure 3 This is a schematic diagram of one side of the moving contact and the arc-extinguishing chamber described in this utility model; Figure 4 This is a schematic diagram showing the cooperation between the moving contact and the inside of the arc-extinguishing chamber described in this utility model; Figure 5 This is a schematic diagram illustrating the cooperation between the moving contact and the moving arc-drawing plate described in this utility model; Figure 6 This is a three-dimensional schematic diagram of the moving arc-guiding plate described in this utility model; Figure 7 This is another three-dimensional schematic diagram of the movable arc-drawing plate described in this utility model; Figure 8 for Figure 6 A front view of the centrally located arc-starting plate; Figure 9 This is a three-dimensional schematic diagram of the gas-generating component described in this utility model; Figure 10 This is a side view of the gas-generating component described in this utility model.

[0017] In the diagram: 1. Arc-extinguishing chamber; 11. Side plate; 12. Grid plate; 13. Moving arc-starting plate; 131. First part; 132. Second part; 133. Central arc-starting part; 134. Lateral arc-starting part; 135. Relief notch; 136. Mounting protrusion; 14. Gas-generating component; 141. Extension part; 142. Covering part; 143. Mounting rib; 144. Gas-generating protrusion; 1441. Fin; 145. Stationary contact mating part; 146. Inclined part; 15. Arc-extinguishing cover; 16. Anti-freezing bracket; 2. Moving contact; 21. Contact piece; 211. Long contact piece; 2111. Arc-starting head; 212. Short contact piece; 213. Main contact; 214. Arc contact; 22. Contact support; 23. Outlet bar; 3. Shell; 31. Base; 32. Bottom plate. Detailed Implementation

[0018] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of this utility model should be considered within the protection scope of this utility model.

[0019] In the following description, all directional (or orientational) concepts involving up, down, left, right, front, and back refer to the position of the figure being described, and are intended to facilitate public understanding. Therefore, they should not be construed as a special limitation on the technical solution provided by this utility model.

[0020] like Figure 1 , 2 The switch includes a disconnector and a circuit breaker. The switch comprises an arc-extinguishing chamber 1, a contact system, and a housing 3. The housing 3 includes a base 31 and a bottom plate 32, which are joined together to form the housing 3. Typically, the base 31 and the bottom plate 32 are secured using threaded fastening.

[0021] The contact system includes a moving contact 2 and a stationary contact (not shown in the figure). The moving contact 2 is mounted on the base 31, while the stationary contact is mounted on the base plate 32. Specifically, the moving contact 2 is rotatably mounted, while the stationary contact is fixedly mounted. After the moving contact 2 actuates, it makes contact with or separates from the stationary contact. The arc-extinguishing chamber 1 is located on one side of the contact system in the opening direction.

[0022] like Figure 2 The arc-extinguishing chamber 1 includes a pair of side plates 11 and multiple grid plates 12 disposed between the pair of side plates 11. The multiple grid plates 12 are spaced apart from each other. The arc-extinguishing chamber 1 also includes a moving arc-initiating plate 13, a deionization component, and an arc-extinguishing cover 15. One end of the moving arc-initiating plate 13 is placed outside the array of grid plates 12 and spaced apart from a nearby grid plate 12. The other end is bent and extends into the interior of the arc-extinguishing chamber 1, forming the extension end of the moving arc-initiating plate 13. The moving arc-initiating plate 13 is located on the side corresponding to the moving contact 2. The deionization component is used to deionize the gas at the outlet side of the grid plate 12. Typically, the deionization component should include a perforated plate (not shown in the figure). The perforated plate is located at the outlet side of the grid plate 12 and is adjacent to the grid plate 12.

[0023] The deionization component includes a deionization bracket 16, which is a frame in shape, and the filter unit of the deionization component is installed inside it. A pair of side plates 11 are fixed to both sides of the deionization bracket 16.

[0024] The arc-extinguishing cover 15 is located at the top of the arc-extinguishing chamber 1, and has an exhaust hole thereon. The gas inside the arc-extinguishing chamber 1 is discharged to the outside of the arc-extinguishing chamber 1 through the exhaust hole on the arc-extinguishing cover 15.

[0025] like Figure 3 , 4 The moving contact 2 includes a contact piece 21, a contact support 22, and a lead-out bar 23. Multiple contact pieces 21 are mounted on the contact support 22, typically hinged together by a pivot, allowing the contact pieces 21 to swing with the contact support 22 while also enabling a certain angle of rotational engagement. The lead-out bar 23 is fixed inside the housing 3, with one end extending outside the housing 3. A conductive flexible connection (not shown in the figure) is provided between the lead-out bar 23 and the contact piece 21 to achieve electrical connection. This conductive flexible connection ensures electrical connection between the contact piece 21 and the lead-out bar 23 without affecting the swinging of the contact piece 21.

[0026] The contact pieces 21 are multiple and arranged side by side. Each contact piece 21 includes long contact pieces 211 and short contact pieces 212. Preferably, each contact piece 21 includes a group of long contact pieces 211, each having at least one long contact piece 211. This group of long contact pieces 21 is located in the center of the contact piece 21 array. Specifically, in this embodiment, there are two long contact pieces 211, adjacent to each other, forming one group. The short contact pieces 212 are divided into two groups, with each group of short contact pieces 212 located on either side of a group of long contact pieces 211. More specifically, in this embodiment, five short contact pieces 212 form one group, that is, ten short contact pieces 212 form two groups.

[0027] See you later Figure 3 and Figure 4 The arc-extinguishing chamber 1 further includes a pair of gas-generating elements 14, which are respectively located at the lower edge of the grid plate 12. Preferably, the pair of gas-generating elements 14 respectively wrap around a pair of grid plate legs of the grid plate 12. The pair of gas-generating elements 14 are arranged opposite to each other, forming a flared opening. The flared opening cooperates with the contact plate 21 to form a flared opening that is wider at the bottom and narrower at the top. Here, the flared opening refers to the portion that narrows on both sides in the upward direction, excluding the straight portion with a constant width or the enlarged portion that increases in the upward direction.

[0028] For the purposes of this invention, the flared opening may refer only to a portion of the space formed by the pair of gas-generating components 14 facing each other, rather than the entire space formed by the pair of gas-generating components 14 facing each other. For example, the flared opening may be located at the lower edge, middle, or upper edge of the space formed by the pair of gas-generating components 14 facing each other.

[0029] Furthermore, the gas-generating component 14 includes an extension 141. A pair of extensions 141 extend toward the contact piece 21, with the space between them forming a front cavity. The pair of extensions 141 extend past both sides of the side-by-side contact pieces 21, thereby ensuring that the electric arc generated on the contact piece 21 is located within the cavity of the flared opening. Specifically, the extension 141 extends past the head of the short contact piece 212, and the head of the short contact piece 212 is located within the front cavity. Preferably, the arc contact point 214 on the short contact piece 212 is located within the front cavity. The aforementioned statement that the arc contact point 214 on the short contact piece 212 is located within the front cavity means that the arc contact point 214 on the short contact piece 212 remains within the front cavity throughout its entire movement. Meanwhile, the head of the long contact piece 211 is located within the flared opening, specifically within the 1 / 2 region of the enlarged side of the flared opening.

[0030] The flared opening is located between the stationary contact and the extended end of the moving arc-drawing plate 13. Alternatively, the flared opening extends from the stationary contact side toward the moving arc-drawing plate 13 and is offset from the moving arc-drawing plate 13.

[0031] The above-described configuration enables the electric arc to be focused and allows it to enter the grid plate 12 through the flared opening; and the flared opening also accelerates the airflow, facilitating the rapid entry of the electric arc into the grid plate 12.

[0032] like Figure 5 This is a schematic diagram showing the interaction between the movable arc-drawing plate 13 and the movable contact 2. Both the long contact plate 211 and the short contact plate 212 are provided with a main contact 213 and an arc contact 214. The arc contact 214 is located above the main contact 213, that is, the arc contact 214 is located on the side of the main contact 213 closer to the grid plate 12. The arc contact 214 is located within the front cavity held by a pair of extensions 141.

[0033] Combination Figure 3 In this embodiment, the arc contact point 214 of the long contact piece 211 is also located below the flared opening. That is, the arc contact points 214 of both the long contact piece 211 and the short contact piece 212 are located below the flared opening.

[0034] The long contact piece 211 has an extended arc-inducing head 2111. After the long contact piece 211 and the short contact piece 212 are installed, the arc-inducing head 2111 is located on the side of the head of the short contact piece 212 closer to the grid plate 12, that is, the arc-inducing head 2111 is higher than the head of the short contact piece 212. The arc-inducing head 2111 is sickle-shaped and extends and curves towards the back side of the long contact piece 211.

[0035] See Figure 6 The movable arc-inducing plate 13 is machined from a metal plate. Alternatively, it can be machined from a metal casting. The movable arc-inducing plate 13 includes a first part 131, a second part 132, a central arc-inducing part 133, and a lateral arc-inducing part 134. The first part 131 is located on the outer side of the array of grid plates 12 in the array direction, and is parallel to and spaced apart from one of the adjacent grid plates 12. The second part 132 is located below the first part 131 and bends inward toward the interior of the arc-extinguishing chamber 1. The second part 132 has an internal notch in the middle of its bottom. The central arc-drawing part 133 bends inward from the internal notch of the second part 132 into the arc-extinguishing chamber 1, while the lateral arc-drawing part 134 bends inward from the lower edge of the second part 132 into the arc-extinguishing chamber 1. There is a height difference between the central arc-drawing part 133 and the lateral arc-drawing part 134. Specifically, the central arc-drawing part 133 is located above the lateral arc-drawing part 134, while the lateral arc-drawing part 134 is located below the central arc-drawing part 133. The central arc-drawing part 133 is configured to cooperate with the long contact piece 211, while the lateral arc-drawing part 134 is configured to cooperate with the short contact piece 212.

[0036] See you later Figure 6 Preferably, the lateral arc-drawing portions 134 are a pair, located on either side of the central arc-drawing portion 133. The central arc-drawing portion 133 is V-shaped, and similarly, the lateral arc-drawing portions 134 are also V-shaped. That is, the central arc-drawing portion 133 bends inward toward the arc-extinguishing chamber 1 and then bends outward toward the arc-extinguishing chamber 1. Similarly, the lateral arc-drawing portions 134 bend inward toward the arc-extinguishing chamber 1 and then bend outward toward the arc-extinguishing chamber 1.

[0037] More preferably, a clearance notch 135 is provided on the outer side of the lateral arc-inducing part 134. The presence of the clearance notch 135 allows the moving arc-inducing piece 13 to avoid other parts inside the arc-extinguishing chamber 1 during installation.

[0038] Mounting protrusions 136 are also provided at intervals on both sides of the moving arc-guiding plate 13. The mounting protrusions 136 are used to mount the moving arc-guiding plate 13 between the pair of side plates 11.

[0039] See Figure 7 This illustrates another structure of the moving arc plate 13, which is similar to... Figure 6 The difference between the movable arc-drawing plate 13 shown is that the central arc-drawing portion 133 and the lateral arc-drawing portion 134 are both flat and do not bend outward to form a V-shape.

[0040] See Figure 8 The width of the central arc-drawing portion 133 is 'a', and the width of the lateral arc-drawing portions 134 is 'b'. The width of the gap formed between the central arc-drawing portion 133 and the lateral arc-drawing portions 134 is 'c'. Preferably, the width of the central arc-drawing portion 133 is less than or equal to the sum of the widths of the two lateral arc-drawing portions 134. More preferably, the widths of the two lateral arc-drawing portions 134 are equal, and the width 'a' of the central arc-drawing portion 133 is twice the width 'b' of the lateral arc-drawing portions 134.

[0041] After the arc-extinguishing chamber 1 and the moving contact 2 are installed, when the moving contact 2 is rotated to a position directly opposite the central arc-initiating part 133, the distance between the long contact piece 211 and the central arc-initiating part 133 is less than the width c of the notch. Specifically, the distance between the top surface of the arc-initiating head 2111 of the long contact piece 211 and the central arc-initiating part 133 is less than the width c of the notch, thereby preventing the arc from jumping from the central arc-initiating part 133 to the lateral arc-initiating part 134.

[0042] In this embodiment, the width 'a' of the central arc-initiating portion 133 is greater than or equal to the width of a set of long contact pieces 211, and less than or equal to 2.5 times the width of a set of long contact pieces 211. In the above description, after installation, the width of the set of long contact pieces 211 in the width direction, i.e., the direction in which the contact pieces 21 are arranged side-by-side, is the width of the set of long contact pieces 211. This structure ensures that the arc generated on the short contact piece 212 can smoothly enter the arc-extinguishing chamber 1, while preventing the arc from retreating from the central arc-initiating portion 133 to the lateral arc-initiating portion 134 and causing breakdown on the short contact piece 212.

[0043] like Figure 8 , 9 This is a schematic diagram of the gas-generating component 14. The gas-generating component 14 is typically made of a gas-generating insulating material. In addition to the extension 141, the gas-generating component 14 also includes a covering portion 142, a mounting rib 143, a gas-generating protrusion 144, a stationary contact mating portion 145, and an inclined portion 146.

[0044] The covering portion 142 is used to cover the grid legs of the grid plate 12. The covering portion 142 extends inward from the end of the arc-extinguishing chamber 1 corresponding to the stationary contact. That is, the covering portion 142 extends from the end of the arc-extinguishing chamber 1 corresponding to the stationary contact towards the moving contact 2. The inclined portion 146 is located on the inner surface of the covering portion 142 and on the side of the covering portion 142 away from the stationary contact. The central arc-inducing portion 133 extends beyond the pair of inclined portions 146, that is, the central arc-inducing portion 133 intersects with the inclined portions 146, while the lateral arc-inducing portion 134 is located below the inclined portions 146. Even when the moving arc-inducing plate 13 does not have the lateral arc-inducing portion 134, and the central arc-inducing portion 133 is interspersed with the inclined portions 146 on the covering portion 142, it can still ensure that the arc fully enters the grid plate 12.

[0045] The mounting rib 143 extends from the side of the covering portion 142 near the grid plate 12 into the arc extinguishing chamber 1 and is fixedly installed with the side plate 11.

[0046] The gas-generating protrusion 144 extends inward from the inner side of a pair of gas-generating elements 14. In this embodiment, the gas-generating protrusion 144 is composed of multiple spaced-apart fins, ensuring that airflow passes through the gaps between adjacent fins. In this embodiment, the number of fins is preferably six, but in practical applications it is not limited to this number; for example, it can be two, three, etc. Furthermore, in this embodiment, the fins are sheet-like. However, for the purposes of this invention, the gas-generating protrusion 144 can be of other shapes, such as a raised edge, arranged columnar protrusions, or other protrusions forming a raised shape. Each pair of gas-generating elements 14 is provided with a gas-generating protrusion 144. The gas-generating protrusion 144 can be individually formed and then installed on the covering portion 142 of the gas-generating element 14. The gas-generating protrusion 144 and the covering portion 142 can be integrally formed.

[0047] Preferably, the gas-generating protrusion 144 is located only on the covering portion 142. Specifically, the gas-generating protrusion 144 is located only on the side of the arc-extinguishing chamber 1 facing the stationary contact. More specifically, the gas-generating protrusion 144 corresponds to one end of the stationary contact and extends towards the moving contact 2. The extension length of the gas-generating protrusion 144 is not required; typically, the extension length of the gas-generating protrusion 144 is less than the dimension of the covering portion 142 in the same direction.

[0048] In this embodiment, the flange of the fin is triangular in shape, preferably a triangle with rounded corners at the top. The flange of the fin can also be other shapes, such as an arc shape.

[0049] When the flange of the fin is triangular, the angle between its lower edge and the horizontal line of the arc-extinguishing chamber 1 is α. The angle α is greater than or equal to 5º and less than or equal to 35º, preferably greater than or equal to 10º and less than or equal to 25º, thereby reducing the obstruction to the airflow.

Claims

1. A contact arc-extinguishing device for a switch, comprising an arc-extinguishing chamber (1) and a contact system, wherein the contact system comprises a moving contact (2) and a stationary contact, the arc-extinguishing chamber (1) is located on one side of the contact system in the opening direction, the arc-extinguishing chamber (1) comprises a moving arc-inducing piece (13), and the contact piece (21) of the moving contact (2) comprises a set of long contact pieces (211) having at least one long contact piece (211) and two sets of short contact pieces (212) located on both sides of the set of long contact pieces (211), characterized in that: The moving arc-drawing plate (13) includes a central arc-drawing portion (133) that cooperates with the long contact plate (211) and two lateral arc-drawing portions (134) that cooperate with the two sets of short contact plates (212). The width of the central arc-drawing portion (133) is less than or equal to the sum of the widths of the two lateral arc-drawing portions (134).

2. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: The width of the central arc-drawing portion (133) is greater than or equal to the width of the set of long contact pieces (211), and less than or equal to 2.5 times the width of the set of long contact pieces (211).

3. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: The two lateral arc-drawing portions (134) have equal widths, and the width of the central arc-drawing portion (133) is twice the width of the lateral arc-drawing portions (134).

4. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: Both the central arc-drawing portion (133) and the lateral arc-drawing portion (134) are flat.

5. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: Both the central arc-drawing part (133) and the lateral arc-drawing part (134) are V-shaped. Both the central arc-drawing part (133) and the lateral arc-drawing part (134) bend towards the inside of the arc-extinguishing chamber (1) and then bend towards the outside of the arc-extinguishing chamber (1).

6. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: The arc-extinguishing chamber (1) includes a pair of side plates (11) and multiple grid plates (12) disposed between the pair of side plates (11), with the multiple grid plates (12) spaced apart from each other; the moving arc-inducing plate (13) also includes a first part (131) and a second part (132), the first part (131) is located outside the array direction of the grid plates (12), the first part (131) is parallel and spaced apart from a grid plate (12) nearby, the second part (132) is located below the first part (131) and bends into the arc-extinguishing chamber (1), the central arc-inducing part (133) is formed by bending into the arc-extinguishing chamber (1) from the internal gap in the middle of the second part (132), and the lateral arc-inducing part (134) is formed by bending into the arc-extinguishing chamber (1) from the lower edge of the second part (132).

7. The contact arc-extinguishing device for a switch according to claim 6, characterized in that: A gap is formed between the central arc-drawing portion (133) and the lateral arc-drawing portion (134). When the moving contact (2) rotates to a position directly opposite the central arc-drawing portion (133), the distance between the long contact piece (211) and the central arc-drawing portion (133) is less than the width of the gap.

8. The contact arc-extinguishing device for a switch according to claim 1, characterized in that: There is a clearance notch (135) on the outer side of the lateral arc-drawing portion (134).

9. The contact arc-extinguishing device for a switch according to claim 6, characterized in that: The arc-extinguishing chamber (1) further includes a pair of gas-generating elements (14), which are located at the lower edge of the grid plate (12) and respectively wrap around a pair of grid plate legs of the grid plate (12).

10. The contact arc-extinguishing device of a switch according to claim 9, characterized in that: The gas generating component (14) further includes a covering part (142) and an inclined part (146). The covering part (142) extends from one end of the arc-extinguishing chamber (1) corresponding to the stationary contact to the moving contact (2). The inclined part (146) is located on the inner side of the covering part (142) and is located on the side of the covering part (142) away from the stationary contact. The central arc-inducing part (133) and the inclined part (146) are staggered.

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