An arc-extinguishing device for a switch

Abstract

An arc-extinguishing device for a switch, belonging to the field of low-voltage electrical technology. It includes a magnetic assembly and an insulating cover. The magnetic assembly comprises a central permanent magnet, a pair of side permanent magnets disposed on either side of the central permanent magnet, and a back magnetic plate connecting the pair of side permanent magnets and the central permanent magnet. The insulating cover insulates and encloses the magnetic assembly, and forms a pair of arc-extinguishing channels extending along the movement direction of the switch's moving contact in the space corresponding to the central permanent magnet and the pair of side permanent magnets. The internal magnetic fields of the central permanent magnet and the side permanent magnets are opposite in direction but parallel to the movement plane of the moving contact, allowing the arc to enter one of the arc-extinguishing channels. Advantages: Reliable arc extinguishing in a small space, reliable interruption under high voltage, and reduced product size.

Description

Technical Field

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

[0002] With the development of photovoltaic-storage systems, system voltage levels are continuously increasing. This increase in voltage reduces system current, allowing for smaller equipment size in the entire electrical system and reduced cable losses during transmission. This enables the number of components that can be connected to a single device, thereby improving system efficiency. As system voltage requirements and currents increase, the arc energy generated during the interruption of related components also increases, placing higher demands on arc extinguishing. However, existing disconnecting switches' arc extinguishing structures cannot meet the requirements for reliable interruption under high voltage, exhibiting problems such as poor arc extinguishing effect and inadequate safety performance.

[0003] In view of the above-mentioned existing technology, it is necessary to improve the structure of the arc extinguishing device of the existing switch. To this end, the applicant has made a useful design, and the technical solution to be introduced below is produced in this context. Utility Model Content

[0004] The purpose of this invention is to provide an arc-extinguishing device for a switch that satisfies the requirement of reliable interruption under high voltage while reducing the size of the product.

[0005] The purpose of this invention is to provide an arc-extinguishing device for a switch, which has a symmetrical structure relative to the moving plane of the switch's moving contact. It includes a magnetic assembly and an insulating cover. The magnetic assembly includes a central permanent magnet, a pair of side permanent magnets disposed on either side of the central permanent magnet, and a back magnetic plate connecting the pair of side permanent magnets and the central permanent magnet. The insulating cover insulates and encloses the magnetic assembly, and forms a pair of arc-extinguishing channels extending along the moving direction of the switch's moving contact in the space corresponding to the central permanent magnet and the pair of side permanent magnets. The internal magnetic fields of the central permanent magnet and the side permanent magnets are opposite in direction but parallel to the moving plane of the moving contact, allowing the electric arc to enter one of the arc-extinguishing channels.

[0006] In a specific embodiment of this utility model, the insulating cover includes a middle partition arc plate, a pair of arc-blocking plates disposed on both sides of the middle partition arc plate, and a pair of back plates connecting the pair of arc-blocking plates and the middle partition arc plate. The middle partition arc plate cooperates with the arc-blocking plates and the back plates on both sides to form the pair of arc-blowing channels.

[0007] In another specific embodiment of this utility model, the pair of arc-blocking plates are open towards the moving contact to form an opening for an arc-extinguishing device. The opening is connected to the pair of arc-blowing channels. When the moving contact is in the closed position and during the separation process of the moving contact until the moving contact reaches the open position, the end of the moving contact is located in the opening.

[0008] In another specific embodiment of this utility model, the magnetic assembly further includes a pair of side magnetic guide plates, which are disposed close to the opening and respectively remain in the same plane with a pair of side permanent magnets.

[0009] In another specific embodiment of this utility model, the insulating cover further includes a rear cover and a front cover. The rear cover surrounds the back plate and the pair of arc-blocking plates on the outside. The space between the rear cover and the back plate is used to accommodate the back magnetic plate, while the space between the rear cover and the pair of arc-blocking plates is used to accommodate the side permanent magnet and the side magnetic plate. There is a pair of front covers, which connect the arc-blocking plates and the end of the rear cover near the opening, and seal the end of the pair of side magnetic plates near the opening.

[0010] In another specific embodiment of this utility model, the insulating cover further includes a top cover shell, which seals one end of the moving contact near the opening position of the intermediate permanent magnet, the side permanent magnet, the back magnetic guide plate, and the side magnetic guide plate.

[0011] In a further specific embodiment of this utility model, the rear cover has a buckle in the middle of the inner bottom wall for positioning the intermediate permanent magnet.

[0012] In a further specific embodiment of this utility model, the inner sidewall of the arc-blocking plate is provided with several protruding ribs at intervals for limiting the side magnetic guide plate, and the ends of the protruding ribs are provided with mounting guide surfaces.

[0013] Because of the above-mentioned structure, this utility model has a permanent magnet, a magnetic plate and an insulating cover installed in a small space. It has no requirements on the polarity of the switch. By using the magnetic field generated by the permanent magnet, in conjunction with the action of the magnetic plate, the electric arc can be quickly guided, stretched and squeezed into the arc blowing channel in the insulating cover by magnetic blowing, thereby realizing the reliable extinguishing of the electric arc in a small space, meeting the requirements of reliable disconnection under high voltage, and reducing the size of the product. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the internal structure of the switch described in this utility model;

[0015] Figure 2 This is an internal front view of the switch described in this utility model;

[0016] Figure 3 This is a perspective view of the arc-extinguishing device described in this utility model;

[0017] Figure 4 This is a front view of the arc-extinguishing device described in this utility model;

[0018] Figure 5 This is an exploded view of the arc-extinguishing device described in this utility model;

[0019] Figure 6 This is a schematic diagram illustrating the arc-extinguishing principle of this invention when current flows from the moving contact to the stationary contact.

[0020] Figure 7 This is a schematic diagram illustrating the arc-extinguishing principle of this invention when current flows from the stationary contact to the moving contact.

[0021] In the diagram: 1. Magnetic assembly, 10. Opening, 11. Central permanent magnet, 12. Side permanent magnet, 13. Back magnetic guide plate, 14. Side magnetic guide plate; 2. Insulating cover, 20. Arc blowing channel, 21. Central arc blocking plate, 210. Cavity, 22. Arc blocking plate, 221. Rib, 2211. Mounting guide surface, 23. Back plate, 24. Rear cover, 241. Buckle, 25. Front cover, 26. Top cover; 3. Outer shell; 4. Stationary contact; 5. Moving contact, 51. Rotating bracket, 52. Moving contact guide rod, 521. End. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] See Figure 1 This utility model relates to an arc extinguishing device for a switch. The arc extinguishing device is installed in the switch. The switch also includes a housing 3, a stationary contact 4 fixedly disposed in the housing 3, and a moving contact 5 rotatably disposed in the housing 3 and in contact with or separating from the stationary contact 4. The arc extinguishing device is used to extinguish the electric arc generated between the moving contact 5 and the stationary contact 4 when they separate.

[0025] See Figure 2Taking a double-break isolating switch as an example, the switch of this utility model includes a pair of stationary contacts 4 symmetrically arranged within the housing 3, with the rotation center of the moving contact 5. The moving contact 5 includes a rotating bracket 51 and a pair of moving contact guide rods 52 symmetrically extending from the circumferential side of the rotating bracket 51. The pair of moving contact guide rods 52 respectively contact or separate from their corresponding stationary contacts 4. During movement, the moving contact 5 forms an arc-shaped movement path a. Corresponding to this double-break isolating switch, a pair of arc-extinguishing devices are also provided, each corresponding to a pair of moving and stationary contacts. When the moving contact 5 and stationary contact 4 are in contact, the switch is closed. When the moving contact 5 and stationary contact 4 separate, the moving contact 5 gradually moves away from the stationary contact 4 until it reaches the open position, at which point the switch is open. Thus, the moving contact 5 rotates to form a moving plane.

[0026] See Figures 3 to 5 and combined Figure 1 The arc-extinguishing device has a symmetrical structure relative to the plane of motion of the moving contact 5, specifically including a magnetic assembly 1 and an insulating cover 2. The insulating cover 2 insulatingly encloses the magnetic assembly 1, including a central arc-blocking plate 21, a pair of arc-blocking plates 22 disposed on both sides of the central arc-blocking plate 21, and a pair of back plates 23 connecting the pair of arc-blocking plates 22 and the central arc-blocking plate 21. It also includes a rear cover 24 surrounding the back plates 23 and the pair of arc-blocking plates 22. The pair of arc-blocking plates 22 are symmetrically arranged relative to the plane of motion of the moving contact 5, and are open towards the moving contact 5 to form an opening 10 for the arc-extinguishing device. The central arc-blocking plate 21, in conjunction with the arc-blocking plates 22 and the back plates 23 on both sides, forms a pair of arc-blowing channels 20 extending along the direction of motion of the moving contact 5 and communicating with the opening 10. These arc-blowing channels 20 are narrow slit-shaped channels.

[0027] The magnetic assembly 1 includes a central permanent magnet 11, a pair of side permanent magnets 12 disposed on both sides of the central permanent magnet 11, and a pair of back magnetic guide plates 13 connecting the pair of side permanent magnets 12 and the central permanent magnet 11 to form an E-shaped cross-section of the magnetic assembly 1. It also includes a pair of side magnetic guide plates 14, which are positioned close to the opening 10 and respectively remain in the same plane as the pair of side permanent magnets 12. Specifically, the central arc-blocking plate 21 is located on the movement plane of the moving contact 5, forming a cavity 210 inside, within which the central permanent magnet 11 is arranged. In this embodiment, the side of the central permanent magnet 11 facing the moving contact 5 is a plane. Alternatively, the side of the central permanent magnet 11 facing the moving contact 5 can be configured to extend in an arc shape closely following the movement trajectory of the moving contact 5, forming an arc-shaped extension surface, the size of which is close to the radius of rotation of the moving contact 5. The space between the rear cover 24 and the back plate 23 is used to accommodate the back magnetic plate 13, while the space between the rear cover 24 and the pair of arc-blocking plates 22 is used to accommodate the side permanent magnet 12 and the side magnetic plate 14. The rear cover 24 has a buckle 241 in the middle of its inner bottom wall for positioning the intermediate permanent magnet 11; the inner wall of the arc-blocking plate 22 has several protruding ribs 221 at intervals for limiting the position of the side magnetic plate 14. The arc-blocking plate 22 and the side magnetic plate 14 are tightly fitted together, and the ends of the protruding ribs 221 are provided with inclined surfaces to form installation guide surfaces 2211. Please refer to [reference needed]. Figure 5 When the magnetic assembly 1 is installed into the insulating cover 2 from the side of the top cover 26 (which will be described below), the installation guide surface 2211 initially guides the side magnetic guide plate 14 into the space between the arc-blocking plate 22 and the rear cover 24. The insulating cover 2 also includes a pair of front covers 25 and a top cover 26. The front covers 25 connect the arc-blocking plate 22 and the rear cover 24 near the opening 10, sealing the ends of the pair of side magnetic guide plates 14 near the opening 10. The top cover 26 seals the ends of the intermediate permanent magnet 11, the side permanent magnet 12, the back magnetic guide plate 13, and the side magnetic guide plate 14 near the moving contact at the opening position. The end of the arc-extinguishing device near the stationary contact 4 is defined as the bottom of the arc-extinguishing device, and the end of the arc-extinguishing device away from the stationary contact 4 is defined as the top of the arc-extinguishing device. The opening 10 is located at the front of the arc-extinguishing device, and the rear cover 24 is the back of the arc-extinguishing device. The function of the top cover 26 is to cover the top of the three cavities: the cavity 210, the space between the rear cover 24 and the back plate 23, and the space between the rear cover 24 and a pair of baffle plates 22.

[0028] Furthermore, in this embodiment, the pair of side magnetic plates 14 can be omitted, and the area of ​​the side permanent magnet 12 can be increased. That is, the side permanent magnet 12 and the side magnetic plates 14 in this embodiment can be replaced by a single side permanent magnet 12. In addition, the pair of back magnetic plates 13 can also be replaced by a single magnetic plate.

[0029] The insulating cover 2 serves two purposes: firstly, it provides support for the permanent magnet and the magnetic plate, facilitating the installation and fixation of the magnetic assembly 1 composed of the permanent magnet and the magnetic plate; secondly, the insulating cover 2 forms an arc-extinguishing channel 20, extending along the direction of movement of the moving contact 5 and located on both sides of the moving contact 5, allowing the arc generated between the moving contact 5 and the stationary contact 4 to pass through, thus guiding and extinguishing the arc with the help of a magnetic field. The insulating cover 2 can be made of a gas-generating, high-temperature-resistant, non-magnetic material to generate gas for arc extinguishing.

[0030] Furthermore, in this example, there is a gap between the two sides of the central arc-blocking plate 21 and the corresponding side arc-blocking plate 22. The gap between the two sides of the central arc-blocking plate 21 near the moving contact 5 and the corresponding side arc-blocking plate 22 is set to be equal to the gap between the two sides of the central arc-blocking plate 21 away from the moving contact 5 and the corresponding side arc-blocking plate 22. That is, the cross-section of the insulating cover 2 is "mountain" shaped, and its interior forms a "mountain" shaped cavity to accommodate the magnetic component 1. In this case, the central permanent magnet 11 and the two side permanent magnets 12 and side magnetic conductive plates 14 are all arranged in parallel. Alternatively, the gap between the two sides of the central arc-blocking plate 21 near the moving contact 5 and the corresponding side arc-blocking plate 22 can be set to be greater than the gap between the two sides of the central arc-blocking plate 21 away from the moving contact 5 and the corresponding side arc-blocking plate 22. In this case, the cross-section of the insulating cover 2 has a "W" shaped structure.

[0031] See Figure 6 The direction from the opening 10 of the arc-extinguishing device to the rear cover 24 is the depth direction of the arc-extinguishing device. Therefore, the N and S poles of the intermediate permanent magnet 11 are arranged along this depth direction, with the end closer to the opening 10 being the N pole and the end closer to the rear cover 24 being the S pole. The N and S poles of the pair of side permanent magnets 12 are arranged in the same way, also along this depth direction, but the end of the pair of side permanent magnets 12 closer to the opening 10 is the S pole, and the end closer to the rear cover 24 is the N pole. (Continue to...) Figure 2 The intermediate permanent magnet 11 is located outside the arc-shaped movement path a of the moving contact 5, that is, on the side of the moving contact 5 away from its rotation center. In this embodiment, preferably, during the closing position of the moving contact 5 and during the separation process until the moving contact 5 reaches the opening position, the end 521 of the moving contact 5 is located within the opening 10 of the arc-extinguishing device. Figure 2As can be seen, in the direction perpendicular to the paper, during the closing position of the moving contact 5 and during the separation process of the moving contact 5 until the moving contact 5 reaches the opening position, the arc-blocking plate 22 and the side magnetic guide plate 14 cover the end 521 of the moving contact, that is, by Figure 2 It is evident that the arc-shaped motion path a is within the arc-extinguishing device to increase the working space of the two magnetic circuits. Of course, the pair of side magnetic guide plates 14 do not cover the end 521 of the moving contact 5, but rather... Figure 6 As shown, it is also feasible to make the front cover 25 substantially flush with the end 521 of the moving contact 5.

[0032] In this embodiment, because the internal magnetic fields of the intermediate permanent magnet 11 and the side permanent magnet 12 are opposite in direction and both parallel to the moving plane of the moving contact 5, the electric arc enters one of the arc-blowing channels 20. When the current flows from the moving contact 5 to the stationary contact 4, the current direction is perpendicular to the paper and inward. The intermediate permanent magnet 11 and the left side permanent magnet 12 generate a magnetic field. A magnetic circuit is constructed by the side magnetic plate 14 on the left side of the intermediate permanent magnet 11, the left side permanent magnet 12, and the left back magnetic plate 13. Within this magnetic field, the electric arc experiences the Lorentz force F in the direction shown in the diagram. Figure 6 As shown, the electric arc enters the left arc-blowing channel 20 under the drive of the Lorentz magnetic force F; when the current flows from the stationary contact 4 to the moving contact 5, the current direction is perpendicular to the paper and outwards. The middle permanent magnet 11 and the right-side side permanent magnet 12 generate a magnetic field. A magnetic circuit is constructed by the middle permanent magnet 11, the right-side side magnetic plate 14, the right-side side permanent magnet 12, and the right-side back magnetic plate 13. Within this magnetic field, the electric arc is subjected to the Lorentz magnetic force F in the direction shown in the diagram. Figure 7 As shown, the electric arc is driven into the arc-blowing channel 20 on the right by the Lorentz magnetic force F. This demonstrates that the driving, elongation, and extinguishing of the electric arc are independent of the direction of the current.

[0033] Of course, the arrangement direction of the N and S poles of the two permanent magnets is not limited to the above embodiment. The middle permanent magnet 11 can have the S pole at the end near the opening 10 and the N pole at the end near the rear cover 24; in this case, the N pole of the pair of side permanent magnets 12 can be at the end near the opening 10 and the S pole at the end near the rear cover 24. As long as the N and S poles of the permanent magnets are arranged along the depth direction of the arc extinguishing device, that is, the internal magnetic field directions of the middle permanent magnet 11 and the side permanent magnets 12 are opposite but both are parallel to the moving plane of the moving contact 5.

[0034] This invention incorporates a permanent magnet, a magnetic guide plate, and an insulating cover within a relatively small space. It does not require specific switch polarity. Utilizing the magnetic field generated by the permanent magnet, in conjunction with the magnetic guide plate, the arc can be quickly guided, stretched, and squeezed into a narrow slit channel on one side of the arc-extinguishing cover via magnetic blowing. The gas generated by the insulating cover cools the arc, thereby achieving reliable arc extinguishing within a small space, satisfying reliable disconnection under high voltage, and reducing the product size, thus achieving the invention's objective.

Claims

1. An arc-extinguishing device for a switch, having a structure symmetrical with respect to the plane of motion of the moving contact (5) of the switch, comprising a magnetic assembly (1) and an insulating cover (2), characterized in that: the magnetic assembly (1) comprises an intermediate permanent magnet (11), a pair of side permanent magnets (12) disposed on both sides of the intermediate permanent magnet (11), and a back magnetic plate (13) connecting the pair of side permanent magnets (12) and the intermediate permanent magnet (11), the insulating cover (2) insulatingly enclosing the magnetic assembly (1), and forming a pair of arc-extinguishing channels (20) extending along the direction of motion of the moving contact (5) of the switch in the space corresponding to the intermediate permanent magnet (11) and the pair of side permanent magnets (12), the internal magnetic field directions of the intermediate permanent magnet (11) and the side permanent magnets (12) being opposite but parallel to the plane of motion of the moving contact (5), so that an electric arc enters one of the arc-extinguishing channels (20).

2. The arc-extinguishing device for a switch according to claim 1, characterized in that: The insulating cover (2) includes a central partition arc plate (21), a pair of arc-blocking plates (22) disposed on both sides of the central partition arc plate (21), and a pair of back plates (23) connecting the pair of arc-blocking plates (22) and the central partition arc plate (21). The central partition arc plate (21) cooperates with the arc-blocking plates (22) and the back plates (23) on both sides to form the pair of arc-blowing channels (20).

3. The arc-extinguishing device for a switch according to claim 2, characterized in that: The pair of arc-blocking plates (22) are open towards the moving contact (5) to form an opening (10) for the arc-extinguishing device. The opening (10) is connected to the pair of arc-blowing channels (20). When the moving contact (5) is in the closed position and during the separation process of the moving contact (5) until the moving contact (5) reaches the open position, the end (521) of the moving contact (5) is located in the opening (10).

4. The arc-extinguishing device for a switch according to claim 3, characterized in that: The magnetic assembly (1) further includes a pair of side magnetic guide plates (14), which are disposed close to the opening (10) and are respectively kept in the same plane with a pair of side permanent magnets (12).

5. The arc-extinguishing device for a switch according to claim 4, characterized in that: The insulating cover (2) further includes a rear cover (24) and a front cover (25). The rear cover (24) surrounds the back plate (23) and the pair of arc-blocking plates (22) on the outside. The space between the rear cover (24) and the back plate (23) is used to accommodate the back magnetic plate (13), while the space between the rear cover (24) and the pair of arc-blocking plates (22) is used to accommodate the side permanent magnet (12) and the side magnetic plate (14). There is a pair of front covers (25), which connect the arc-blocking plates (22) and the rear cover (24) near the opening (10) and seal the end of the pair of side magnetic plates (14) near the opening (10).

6. The arc-extinguishing device for a switch according to claim 5, characterized in that: The insulating cover (2) also includes a top cover (26), which seals one end of the moving contact (5) near the opening position of the intermediate permanent magnet (11), the side permanent magnet (12), the back magnetic plate (13) and the side magnetic plate (14).

7. The arc-extinguishing device for a switch according to claim 5, characterized in that: The rear cover (24) has a buckle (241) in the middle of the inner bottom wall for positioning the intermediate permanent magnet (11).

8. The arc-extinguishing device for a switch according to claim 5, characterized in that: The inner wall of the arc-blocking plate (22) is provided with several protruding ribs (221) at intervals for limiting the side magnetic guide plate (14). The end of the protruding rib (221) is provided with a mounting guide surface (2211).

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