Contact arc extinguishing device

Abstract

A contact arc extinguishing device belongs to the technical field of switching devices. Comprising a contact system and an arc extinguish chamber, the arc extinguish chamber comprises a plurality of grid sheets, a pair of side plates and a spacing plate, the grid sheets are arrayed between the pair of side plates, the spacing plate divides an inner cavity of the arc extinguish chamber into at least one first arc channel and at least one second arc channel, and a static contact of the contact system comprises a conductive block and a static contact fixed on the conductive block. The arc extinguishing device is characterized in that the static contact further comprises an arc striking piece which is fixed on the conductive block and located on one side, facing the arc extinguishing chamber, of the static contact, the arc striking piece comprises a first arc striking part and a second arc striking part, the first arc striking part corresponds to the first arc channel, and the second arc striking part corresponds to the second arc channel. The device has the advantages that reverse electromagnetic force can be prevented from being generated to prevent electric arcs from quickly entering the grid plates, so that the breaking capacity of the switch equipment can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of switching electrical appliances, and particularly relates to a contact arc extinguishing device. Background Art

[0002] In recent years, with the vigorous development of DC transmission projects, the demand for DC switchgear has been increasing, and the requirements for its breaking capacity have also been getting higher and higher. Since there is no natural zero-crossing point for DC current, the difficulty of DC switchgear in interrupting DC current is significantly greater than that of interrupting AC current, especially for high-voltage DC current. In the prior art, large-sized air circuit breakers usually adopt a multi-contact structure, and there are multiple main contacts and arcing contacts. The main contacts are used to carry current, and the arcing contacts are used to interrupt the current while carrying current. Specifically, the arcing contacts extend into the narrow slit of the arc extinguishing assembly to interrupt the circuit current. When the narrow slit is too wide, it is difficult to interrupt due to the weak driving ability of the arc extinguishing system for small current; if the narrow slit is narrowed, it is beneficial to interrupt small current, but when interrupting large short-circuit current, arcing may also occur on the main contacts, and the arc on the main contacts is difficult to enter the narrow slit, which may lead to unreliable interruption. At the same time, if at least two arc channels cooperate with the same arcing piece, interference will occur, affecting the speed of the arc entering the grid piece. In view of the above existing technologies, it is necessary to further optimize the existing contact arc extinguishing device to avoid interference and affect the speed of the arc entering the grid piece. For this reason, the applicant has made a beneficial design, and the technical solution to be introduced below is generated under this background. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a contact arc extinguishing device, which can prevent the generation of reverse electromagnetic force from hindering the arc from quickly entering the grid piece, is beneficial to improving the arcing effect, and improving the breaking capacity of the switchgear.

[0004] The purpose of the utility model is achieved in this way. A contact arc extinguishing device includes a contact system and an arc extinguishing chamber. The arc extinguishing chamber includes several grid pieces, a pair of side plates and a partition plate. The several grid pieces are arrayed between the pair of side plates. The partition plate divides the inner cavity of the arc extinguishing chamber into at least one first arc channel and a second arc channel. The static contact of the contact system includes a conductive block and a static contact point fixed on the conductive block. The static contact also includes an arcing piece fixed on the conductive block and located on the side of the static contact point facing the arc extinguishing chamber. The arcing piece includes a first arcing part and a second arcing part. The first arcing part and the second arcing part are arranged at intervals. The first arcing part corresponds to the first arc channel, and the second arcing part corresponds to the second arc channel.

[0005] In a specific embodiment of the utility model, the partition plate is inserted between the first arcing part and the second arcing part.

[0006] In another specific embodiment of the present utility model, the first arcing portion and the second arcing portion are arranged side by side.

[0007] In yet another specific embodiment of the present utility model, the arcing piece includes an independent first arcing member and a second arcing member. The first arcing portion is located on the first arcing member, and the second arcing portion is located on the second arcing member.

[0008] In still another specific embodiment of the present utility model, the first arcing portion is in a straight strip shape, and the second arcing portion is also in a straight strip shape.

[0009] In still another specific embodiment of the present utility model, the second arcing member includes a mounting portion, a connecting portion, and a head portion. The connecting portion connects the mounting portion and the head portion.

[0010] In yet another specific embodiment of the present utility model, the first arc channel forms a first narrow slit, and the second arc channel forms a second narrow slit and a flared opening.

[0011] In a further specific embodiment of the present utility model, the moving contact of the contact system includes a short contact piece, a first long contact piece, and a second long contact piece. The first long contact piece is in contact and cooperation with the first arcing portion, the second long contact piece is in contact and cooperation with the second arcing portion, and the short contact piece is in contact and cooperation with the static contact point.

[0012] In yet another more specific embodiment of the present utility model, during the closing process of the contact system, in the order from first to last: the contact between the first arc contact point of the first long contact piece and the first arcing portion, the contact between the second arc contact point of the second long contact piece and the second arcing portion, the contact between the moving contact point of the moving contact and the static contact point; the separation process of the contact system is opposite to the above order.

[0013] Due to the adoption of the above structure, compared with the prior art, the present utility model has the beneficial effect that by arranging two independent arc channels inside the arc extinguishing chamber, the arcing piece has a first arcing portion and a second arcing portion in its extending direction, and the first arcing portion and the second arcing portion are spaced apart, thereby being able to prevent the generation of a reverse electromagnetic force from hindering the arc from quickly entering the grid piece, and thus being able to improve the breaking capacity of the switchgear. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 An exploded view of the first embodiment related to the present utility model;

[0015] Figure 2 A perspective view of the first embodiment related to the present utility model;

[0016] Figure 3 Internal cross-sectional view of the first embodiment related to the present utility model;

[0017] Figure 4 Structural schematic diagram of the moving contact piece in the first embodiment related to the present utility model;

[0018] Figure 5 Structural schematic diagram of the covering member in the first embodiment related to the present utility model;

[0019] Figure 6 Structural schematic diagram of the orifice plate in the first embodiment related to the present utility model;

[0020] Figure 7 Structural schematic diagram of the moving contact in the second embodiment related to the present utility model;

[0021] Figure 8 Stereogram of the second embodiment related to the present utility model;

[0022] Figure 9 Internal cross-sectional view of the second embodiment related to the present utility model;

[0023] Figure 10 Structural schematic diagram of the first type of arc ignition piece related to the present utility model;

[0024] Figure 11 Structural schematic diagram of the second type of arc ignition piece related to the present utility model;

[0025] Figure 12 Structural schematic diagram of the third type of arc ignition piece related to the present utility model.

[0026] In the figure: 1. Contact system, 11. Moving contact, 111. Short contact piece, 1111. Moving contact point, 112. First long contact piece, 1121. First arc contact point, 113. Second long contact piece, 1131. Second arc contact point, 12. Stationary contact, 121. Stationary contact point, 122. First arc ignition part, 1221. Static arc contact point, 123. Second arc ignition part, 1231. Mounting part, 1232. Connecting part, 1233. Head; 2. Arc extinguishing chamber, 21. Grid piece, 211. Notch, 2111. First notch, 2112. Second notch, 212. Grid piece leg, 213. Main grid piece, 214. End grid piece, 22. Side plate, 221. Gas generating plate, 23. Spacer plate, 231. Second fin, 24. Arc extinguishing cover, 241. Orifice plate, 2411. Ventilation hole, 2412. Protrusion, 2413. Flanging, 242. Cover body, 25. Covering member, 251. First fin, 252. First opposite surface, 253. Second opposite surface, 254. Contact part; 100. First narrow slit, 200. Second narrow slit, 300. Flared opening. Detailed implementation manners

[0027] The following will describe in detail the specific embodiments of the present utility model in conjunction with the accompanying drawings. However, the description of the embodiments does not limit the technical solutions. Any change in form rather than substance based on the concept of the present utility model should be regarded as within the protection scope of the present utility model.

[0028] In the following description, any concepts related to directions (or orientations) such as up, down, left, right, front, and back are in reference to the position state of the figure being described, aiming to facilitate public understanding. Therefore, they should not be construed as special limitations on the technical solutions provided by the present utility model.

[0029] Embodiment 1: Figures 1 to 4 It is a schematic diagram of the first embodiment of the present utility model. Inside the circuit breaker, there are a contact system 1, an arc extinguishing chamber 2, an operating mechanism (not shown in the figure), etc. The operating mechanism is the energy component of the circuit breaker. When the circuit breaker performs closing and opening operations, the contact system 1 is driven by the operating mechanism to close or disconnect. When an arc is generated on the contact system 1, the arc enters the arc extinguishing chamber 2 and is extinguished.

[0030] The contact arc extinguishing device is composed of the contact system 1 and the arc extinguishing chamber 2. The contact system 1 includes a moving contact 11 and a static contact 12. The moving contact 11 is a swinging component, and the static contact 12 is fixedly arranged. That is, the moving contact 11 realizes contact or separation from the static contact 12 through its own swinging.

[0031] The moving contact 11 includes a short contact piece 111 and a first long contact piece 112. The short contact piece 111 and the first long contact piece 112 are arranged side by side. There is a moving contact point 1111 on the short contact piece 111. There is a first arc contact point 1121 on the first long contact piece 112. When the short contact piece 111 and the first long contact piece 112 are installed, the head of the first long contact piece 112 has a greater extension length relative to the head of the short contact piece 111. The first arc contact point 1121 is located above the moving contact point 1111 in the extending direction of the contact piece. For the moving contact 11, except for the first long contact piece 112, other contact pieces are the remaining contact pieces of the moving contact 11. To ensure that an arc is generated on the first long contact piece 112, the separation of the first long contact piece 112 from the static contact 12 is the latest.

[0032] The static contact 12 described above includes a conductive block and a static contact point 121 fixedly arranged on the conductive block. The static contact point 121 is used for contact cooperation with the moving contact point 1111 on the short contact piece 111. An arc guide piece is further arranged on the conductive block. The arc guide piece is fixed on the conductive block and is located on the side of the static contact point 121 facing the arc extinguishing chamber 2. Specifically for the arc guide piece, the arc guide piece includes a first arc guiding part 122 and a second arc guiding part 123. The first arc guiding part 122 and the second arc guiding part 123 are arranged side by side and at intervals. More specifically, the arc guide piece includes an independent first arc guiding member and a second arc guiding member. The first arc guiding part 122 is arranged on the first arc guiding member, and the second arc guiding part 123 is arranged on the second arc guiding member.

[0033] The arc extinguishing chamber 2 described above includes grid pieces 21, side plates 22, spacer plates 23 and an arc extinguishing cover 24. A plurality of grid pieces 21 are arrayed between the pair of side plates 22. Preferably, the grid pieces 21 are installed between the pair of side plates 22 by riveting. The spacer plate 23 is located inside the cavity of the arc extinguishing chamber 2 and divides the cavity of the arc extinguishing chamber 2 into at least two arc channels. The arc channels include at least one first arc channel and one second arc channel. The first long contact piece 112 extends into the first arc channel, and the remaining contact pieces on the moving contact 11 correspond to the second arc channel. The diameter of the first arc channel is smaller than the diameter of the second arc channel. The above diameter can also be referred to as width, that is, the width of the first arc channel is smaller than the width of the second arc channel. The arc extinguishing cover 24 is located on the air outlet side of the grid pieces 21. Specifically, the spacer plate 23 and a nearby side plate 22 form a first arc channel, and the spacer plate 23 and a far side plate 22 form a second arc channel. Of course, the first arc channel and the second arc channel are not limited to being formed by the spacer plate 23 and the side plate 22. It can also be that: the spacer plate 23 is composed of multiple pieces, and the first arc channel or / and the second arc channel are formed by multiple spacer plates 23.

[0034] The first arc guiding part 122 of the first arc guiding member corresponds to the first arc channel, and the second arc guiding part 123 of the second arc guiding member corresponds to the second arc channel. Preferably, the first arc guiding part 122 is in a straight strip shape, which helps the arc to enter the grid pieces 21 along the first arc channel. The second arc guiding member includes a mounting part 1231, a connecting part 1232 and a head part 1233. The connecting part 1232 connects the mounting part 1231 and the head part 1233. The mounting part 1231 is fixed on the conductive block, and the head part 1233 is located at one end of the arrayed grid pieces 21. More preferably, the mounting part 1231 is trapezoidal, the connecting part 1232 is an arched and slender strip shape, and the head part 1233 is in a shape of a rectangular with a missing corner.

[0035] Under the above structure, the first arc contact point 1121 on the first long contact piece 112 is in contact and cooperation with the arc ignition piece. In this embodiment, the first arc contact point 1121 is in contact and cooperation with the first arc ignition part 122. During the closing process of the contact system 1, the contact between the first arc contact point 1121 and the first arc ignition part 122 precedes the contact between the moving contact point 1111 and the static contact point 121. And when the contact system 1 separates, the separation between the first arc contact point 1121 and the first arc ignition part 122 is later than the separation between the moving contact point 1111 and the static contact point 121, so as to ensure that the arc is generated on the first arc contact point 1121 and the first arc ignition part 122. Preferably, a static arc contact point 1221 is provided on the first arc ignition part 122, and the first arc contact point 1121 is in contact and cooperation with the static arc contact point 1221.

[0036] The grid piece 21 includes a base part, and a notch 211 is provided on one side of the base part facing the contact system 1. Each notch 211 corresponds to an arc channel. The grid piece 21 also has at least one grid piece leg 212, and the grid piece leg 212 is located on one side of at least one notch 211. In this embodiment, there are two notches 211, including a first notch 2111 and a second notch 2112. The first notch 2111 corresponds to the first arc channel, and the second notch 2112 corresponds to the second arc channel. Since the width of the first arc channel is smaller than the width of the second arc channel, correspondingly, the first notch 2111 is smaller than the second notch 2112.

[0037] In this embodiment, grid piece legs 212 are provided on both sides of the second notch 2112. The first notch 2111 is located on one side of a side plate 22. Therefore, there is no grid piece leg 212 on the side of the first notch 2111 close to the side plate 22, and the other side of the first notch 2111 shares a grid piece leg 212 with the second notch 2112. Specifically, both the first notch 2111 and the second notch 2112 are triangular, preferably acute-angle notches.

[0038] In this embodiment, the grid piece 21 includes a main grid piece 213 and an end grid piece 214. There are multiple main grid pieces 213 and multiple end grid pieces 214. Multiple main grid pieces 213 are arrayed together to form a group. Similarly, multiple end grid pieces 214 are arrayed together to form a group. A group of end grid pieces 214 is located on the side of a group of main grid pieces 213 away from the static contact 12. The difference between the end grid piece 214 and the main grid piece 213 is that: the grid piece leg 212 of the end grid piece 214 is shorter than the grid piece leg 212 of the main grid piece 213.

[0039] The first arc channel formed by the spacer 23 and the adjacent side plate 22 constitutes the first narrow slit 100. Preferably, in order to facilitate gas generation, a gas generation plate 221 is attached to the side plate 22, and the spacer 23 can be made of a gas generation material or have a gas generation sheet attached to its side. At least one first long contact piece 112 extends into this first arc channel. Specifically, the first long contact piece 112 extends into the first narrow slit 100. Preferably, the head of the first long contact piece 112 extends past the extended end of the grid piece leg 212. Specifically, the head of the first long contact piece 112 extends past the extended end of the grid piece leg 212 of the main grid piece 213. In this embodiment, only one first long contact piece 112 extends into the first arc channel.

[0040] The arc extinguishing chamber 2 further includes a pair of covering members 25. The left covering member 25 is cooperatively installed with the spacer 23 and covers the grid piece legs 212 on the left side of the grid piece 21; while the right covering member 25 and the right side plate 22 cover the grid piece legs 212 on the right side of the grid piece 21.

[0041] See Figure 5 , generally, the covering members 25 are made of a gas generation material. First fins 251 extend from the covering members 25, and the first fins 251 are inserted into the adjacent grid piece legs 212. For the left covering member 25, since the spacer 23 also has second fins 231 extending towards the grid piece legs 212, the second fins 231 are also embedded into the adjacent grid piece legs 212. Specifically, in the extending direction of the grid piece legs 212, the first fins 251 and the second fins 231 are in an adjacent relationship on the front and rear sides in the extending direction of the grid piece legs 212.

[0042] In this embodiment, the moving contact 11 further includes a second long contact piece 113. The short contact piece 111 is located outside the arc extinguishing chamber 2, while the first long contact piece 112 and the second long contact piece 113 extend into the interior of the arc extinguishing chamber 2. The second long contact piece 113 also has a second arc contact point 1131. For the second arc channel, the second long contact piece 113 extends into the second arc channel. Specifically, the first long contact piece 112 and the second long contact piece 113 have the same extending length.

[0043] During the closing process of the contact system 1, the contact between the second arc contact 1131 of the second long contact piece 113 and the second arc guiding part 123 of the static contact 12 precedes the contact between the moving contact 1111 of the short contact piece 111 and the static contact 121 of the static contact 12. When the contact system 1 separates, the separation between the second arc contact 1131 and the second arc guiding part 123 lags behind the separation between the moving contact 1111 and the static contact 121.

[0044] To ensure that the arc is preferentially generated on the first arc contact 1121 of the first long contact piece 112 and the first arc guiding part 122. During the closing process of the contact system 1, the contact between the first arc contact 1121 and the first arc guiding part 122 precedes the contact between the second arc contact 1131 and the second arc guiding part 123. When the contact system 1 separates, the separation between the first arc contact 1121 and the first arc guiding part 122 lags behind the separation between the second arc contact 1131 and the second arc guiding part 123, thereby ensuring that the arc is generated on the first arc contact 1121 and the first arc guiding part 122. That is, during the closing process of the contact system 1, the order from first to last is: the contact between the first arc contact 1121 and the first arc guiding part 122, the contact between the second arc contact 1131 and the second arc guiding part 123, and the contact between the moving contact 1111 and the static contact 121. The separation process of the contact system 1 is opposite to the above order and will not be repeated.

[0045] To ensure the above contact or separation sequence relationship, usually the contact part between the contact support of the contact system 1 and the contact piece can be adjusted. When the moving contact 11 and the static contact 12 are in a separated state, the contact pieces have a certain angular difference.

[0046] See Figure 5 And in combination with Figure 2 、 Figure 3 After a pair of covering parts 25 are installed in place, they face each other. On the opposite sides of the covering parts 25, there are a first opposite surface 252 and a second opposite surface 253. A pair of first opposite surfaces 252 form a second narrow slit 200, while a pair of second opposite surfaces 253 form a flared opening 300 that expands towards the moving contact system 1 side. The flared end of the flared opening 300 corresponds to the short contact piece 111, and the narrowed end of the flared opening 300 corresponds to the second narrow slit 200. The second long contact piece 113 extends into the flared opening 300 and is located outside the second narrow slit 200. The second long contact piece 113 and the short contact piece 111 both correspond to the flared opening 300. That is to say, the arcs generated on the second long contact piece 113 and the short contact piece 111 enter the upper second narrow slit 200 through the flared opening 300. There is also a contact part 254 on the covering part 25. A pair of contact parts 254 are in contact and cooperate with the installation of the moving arc guiding piece of the arc extinguishing chamber 2.

[0047] SeeFigure 6 and in combination with Figure 1 、 Figure 2 The arc extinguishing cover 24 is also fixedly installed between a pair of side plates 22 and is located at the top of the arc extinguishing chamber 2. The arc extinguishing cover 24 includes a hole plate 241, a cover body 242, and a deionization component (not shown in the figure). The deionization component is located above the hole plate 241. More specifically, the hole plate 241 and the deionization component are both accommodated inside the cover body 242. The hole plate 241 is in contact with the gas outlet side of the grid plates 21.

[0048] The hole plate 241 is provided with uniformly arranged ventilation holes 2411 and protrusions 2412. The protrusions 2412 extend downward from the lower side surface of the hole plate 241 and cooperate with the grid plates 21. Specifically, the protrusions 2412 are snapped into the gaps between adjacent grid plates 21 to position the grid plates 21 and ensure the stability of the installation of the grid plates 21. The protrusions 2412 are disposed between adjacent ventilation holes 2411 in the width direction of the hole plate 241 and do not affect the arrangement of the ventilation holes 2411, that is, do not reduce the ventilation volume of all the ventilation holes 2411 on the hole plate 241.

[0049] Specifically, the hole plate 241 is provided with a plurality of rows of ventilation holes 2411 corresponding to the gaps between adjacent grid plates 21. The protrusions 2412 are provided in the rows of ventilation holes 2411. The protrusions 2412 are embedded into the gaps between adjacent grid plates 21. In the above, the ventilation holes 2411 do not require being located within the gaps between the grid plates 21, and part of the ventilation holes 2411 may also be located within the gaps between the grid plates 21. Preferably, there are at least two protrusions 2412, and the protrusions 2412 are evenly distributed in the width direction of the hole plate 241. The protrusions 2412 are arranged at intervals, and a plurality of ventilation holes 2411 are located between and on both sides of each protrusion 2412.

[0050] Furthermore, the protruding height of the protrusions 2412 is greater than one times the thickness of the hole plate 241 and less than three times the thickness of the hole plate 241. Preferably, the protruding height of the protrusions 2412 is two times the thickness of the hole plate 241. In the length direction of the hole plate 241, adjacent protrusions 2412 are staggered from each other.

[0051] More preferably, in order to facilitate the embedding of the protrusions 2412 into adjacent grid plates 21, the protrusions 2412 are conical protrusions, that is, the extending ends of the protrusions 2412 are smaller than the bottoms of the protrusions 2412. The protrusions 2412 can also be trapezoidal protrusions. Of course, they can also be protrusions of other shapes such as triangular. The protrusions 2412 position the gas outlet side of the grid plates 21, so that the grid plates 21 have a better installation and fixing effect.

[0052] Further, above the orifice plate 241, i.e., on the side facing the arc extinguishing cover 24, and corresponding to both sides of a pair of side plates 22, upward flanges 2413 are provided. The flanges 2413 are used for mounting and cooperating with the deionization component, facilitating the orifice plate 241 to carry the deionization component and be received into the inner cavity of the cover body 242 together.

[0053] Continue to see Figure 3 , in the present utility model, since a first narrow slit 100 is provided on one side of the arc extinguishing chamber 2, the first long contact piece 112 extends into the first narrow slit 100, and during the separation process of the moving contact 11 and the static contact 12, the separation of the first long contact piece 112 from the first arc guiding portion 122 is the latest compared to the separation of the second long contact piece 113 from the second arc guiding portion 123 and the separation of the short contact piece 111 from the static contact 12. Therefore, an arc first appears on the first long contact piece 112, and after passing through the first narrow slit 100, the arc enters the grid sheets 21 and extinguishes. For small currents, the small current only passes through the first narrow slit 100 and then enters the grid sheets 21 and extinguishes, but for large currents, in addition to generating an arc on the first long contact piece 112, an arc is also generated on the second long contact piece 113. The arc generated on the second long contact piece 113 passes through the flared opening 300 and then enters the grid sheets 21 through the second narrow slit 200.

[0054] The diameter d1 of the first narrow slit 100 is smaller than the diameter d2 of the second narrow slit 200. Since the first narrow slit 100 corresponds to the first long contact piece 112, and the second narrow slit 200 corresponds to the second long contact piece 113 and the short contact piece 111, and the second narrow slit 200 corresponds to more contact pieces compared to the first narrow slit 100, therefore, a larger diameter of the second narrow slit 200 than that of the first narrow slit 100 can better meet the requirements of large currents.

[0055] Further, see Figure 3 , the flared opening 300 forms an included angle A, and the included angle A better corresponds to the second long contact piece 113 and the short contact piece 111.

[0056] The first notch 2111 and the second notch 2112 respectively correspond to the first narrow slit 100 and the second narrow slit 200. Since the diameter of the second narrow slit 200 is larger than that of the first narrow slit 100, therefore, the opening of the second notch 2112 is larger than the opening of the first notch 2111.

[0057] This structure can fully take into account the case of small current breaking while being suitable for large current breaking.

[0058] Embodiment 2: Figures 7 to 9 It is a schematic diagram of the second embodiment.

[0059] The difference between the second embodiment and the first embodiment is that the moving contact 11 includes a first long contact piece 112 and a short contact piece 111, and does not include the second long contact piece 113. Among them, the first long contact piece 112 corresponds to the first narrow slit 100; while the short contact pieces 111 are arrayed together and correspond to the flared opening 300. The second narrow slit 200 is located above the flared opening 300. The first long contact piece 112 extends into the first narrow slit 100, while the short contact pieces 111 are located outside the flared opening 300, that is, the short contact pieces 111 are located outside the arc extinguishing chamber 2.

[0060] In the first embodiment and the second embodiment, since only one first long contact piece 112 extends into the first narrow slit 100, in order to improve the service life of the first long contact piece 112, the width of the first long contact piece 112 can be wider than that of other contact pieces. Of course, the first arc contact point 1121 also follows and is widened.

[0061] Embodiment 3: The remaining contact pieces of the moving contact 11 further include a second long contact piece 113, that is, the moving contact 11 includes a first long contact piece 112 and a second long contact piece 113. The first narrow slit 100 is formed in the first arc channel, and the second narrow slit 200 is formed in the second arc channel. The first long contact piece 112 extends into the first narrow slit 100, and the second long contact piece 113 extends into the second narrow slit 200. The diameter of the first narrow slit 100 is smaller than that of the second narrow slit 200. When the current is small, an arc is generated on the first long contact piece 112 and enters the grid sheet 21 through the first narrow slit 100 to be extinguished. When the current is large, an arc will also be generated on the second long contact piece 113 and enter the grid sheet 21 through the second narrow slit 200 to be extinguished. At this time, the requirements for interrupting both small and large currents are taken into account.

[0062] Due to the adoption of the above structure, compared with the prior art, the beneficial effects of the present utility model are as follows: The partition plate 23 divides the inner cavity of the arc extinguishing chamber 2 into at least two arc channels. The arc channels include at least one first arc channel and one second arc channel. The first long contact piece 112 extends into the first arc channel, and the remaining contact pieces on the moving contact 11 correspond to the second arc channel. The diameter of the first arc channel is smaller than that of the second arc channel. The first arc channel is used to handle the interruption of small currents, and the second arc channel is used to handle large currents. It can fully take into account the interruption of small currents in the case suitable for interrupting large currents, so as to meet the developing interruption requirements.

[0063] Such as Figure 10, is a structural schematic diagram of the first arcing piece. Since the arcing piece in this solution includes an independent first arcing member and a second arcing member, where the first arcing portion 122 is located on the first arcing member, and the second arcing portion 123 is located on the second arcing member. When an arc is generated and current flows from the moving contact 11 through the arc into the static contact 12, when it enters the first arcing portion 122 of the static contact 12, it will only flow downward along the L1 path and will not flow along the L2 path, thus avoiding the electromagnetic force that pushes the arc downward when flowing along the L2 path.

[0064] Such as Figure 11 , is a structural schematic diagram of the second arcing piece. The difference between it and the structure of the first arcing piece is that: both the first arcing member and the second arcing member are straight strips. More specifically, the first arcing portion 122 and the second arcing portion 123 are also straight strips. When an arc is generated and current flows from the moving contact 11 through the arc into the static contact 12, when it enters the first arcing portion 122 of the static contact 12, it will only flow downward along the L1 path and will not flow along the L2 path, thus avoiding the electromagnetic force that pushes the arc downward when flowing along the L2 path.

[0065] Such as Figure 12 , is a structural schematic diagram of the third arcing piece. The difference between it and the structure of the second arcing piece is that: the fixed end of the arcing piece is one, and from the fixed end of the arcing piece to the extension side of the arc extinguishing chamber 2, it is divided into a first arcing portion 122 and a second arcing portion 123, and the first arcing portion 122 and the second arcing portion 123 are arranged at intervals. When an arc is generated and current flows from the moving contact 11 through the arc into the static contact 12, when it enters the first arcing portion 122 of the static contact 12, it will only flow downward along the L1 path and will not flow along the L2 path, thus avoiding the electromagnetic force that pushes the arc downward when flowing along the L2 path.

Claims

1. A contact arc extinguishing device, comprising a contact system (1) and an arc extinguishing chamber (2), wherein the arc extinguishing chamber (2) comprises a plurality of grid plates (21), a pair of side plates (22) and a partition plate (23), wherein the plurality of grid plates (21) are arrayed between the pair of side plates (22), and the partition plate (23) divides the inner cavity of the arc extinguishing chamber (2) into at least one first arc channel and one second arc channel, wherein the stationary contact (12) of the contact system (1) comprises a conductive block and a stationary contact point (121) fixed on the conductive block, wherein the stationary contact (12) further comprises an arc striking piece fixed on the conductive block and located on the side of the stationary contact point (121) facing the arc extinguishing chamber (2), wherein: The arc-striking piece comprises a first arc-striking portion (122) and a second arc-striking portion (123), wherein the first arc-striking portion (122) and the second arc-striking portion (123) are arranged at intervals, wherein the first arc-striking portion (122) corresponds to a first arc channel, and the second arc-striking portion (123) corresponds to a second arc channel.

2. The contact arc extinguishing device according to claim 1, characterized in that: The partition plate (23) is inserted between the first arc-striking portion (122) and the second arc-striking portion (123).

3. The contact arc extinguishing device according to claim 1, characterized in that: The first arc-starting portion (122) and the second arc-starting portion (123) are arranged side by side.

4. The contact arc extinguishing device according to claim 1, characterized in that: The arc-striking piece comprises a first arc-striking piece and a second arc-striking piece which are independent of each other. The first arc-striking portion (122) is located on the first arc-striking piece, and the second arc-striking portion (123) is located on the second arc-striking piece.

5. The contact arc extinguishing device according to claim 1, characterized in that: The first arc-starting portion (122) is in the shape of a straight bar, and the second arc-starting portion (123) is also in the shape of a straight bar.

6. The contact arc extinguishing device according to claim 4, characterized in that: The second arc-starting member comprises a mounting portion (1231), a connecting portion (1232) and a head portion (1233), wherein the connecting portion (1232) connects the mounting portion (1231) and the head portion (1233).

7. The contact arc extinguishing device according to claim 1, characterized in that: A first narrow slit (100) is formed in the first arc channel, and a second narrow slit (200) and a flared opening (300) are formed in the second arc channel.

8. The contact arc extinguishing device according to claim 1, characterized in that: The moving contact (11) of the contact system (1) comprises a short contact piece (111), a first long contact piece (112) and a second long contact piece (113); the first long contact piece (112) is in contact with a first arc-striking portion (122), the second long contact piece (113) is in contact with a second arc-striking portion (123), and the short contact piece (111) is in contact with the static contact (121).

9. The contact arc extinguishing device according to claim 8, characterized in that: During the closing process of the contact system (1), the order from first to last is: the first arc contact (1121) of the first long contact piece (112) contacts the first arc striking portion (122), the second arc contact (1131) of the second long contact piece (113) contacts the second arc striking portion (123), and the moving contact (1111) of the moving contact (11) contacts the stationary contact (121); the separation process of the contact system (1) is the opposite of the above order.

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