Arc extinguishing system of switch contacts

Abstract

An arc-extinguishing system for a switch belongs to the field of low-voltage electrical technology. It 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-initiating piece. The moving contact's contact piece includes a set of long contact pieces, each having at least one long contact piece, and two sets of short contact pieces located on either side of the set of long contact pieces. The moving arc-initiating piece includes a central arc-initiating portion that mates with the long contact pieces and a lateral arc-initiating portion that mates with the short contact pieces. During the separation of the moving contact and the stationary contact, the arc-initiating head of the long contact piece first enters the space below the central arc-initiating portion, while the head of the short contact piece subsequently enters the space below the lateral arc-initiating portion. The advantage is that it ensures that the arc enters the arc-extinguishing chamber from the central arc-initiating portion and does not move downwards along the lateral arc-initiating portion, causing breakdown on the short contact pieces.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical technology, specifically relating to a contact arc extinguishing system for 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, breaking the switch becomes extremely difficult. Therefore, switches usually include an arc-extinguishing chamber to extinguish the arc generated when the moving and stationary contacts separate. The circuit is only broken when the arc is extinguished. 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, during the actual breaking process of the switch, an electric arc often appears on the short contact piece. At this time, how to quickly introduce the electric arc into the arc-extinguishing chamber has become a problem of concern in the industry. Utility Model Content

[0004] The purpose of this invention is to provide a contact arc extinguishing system for a switch. During the separation of the moving contact and the stationary contact, the arc-inducing head of the long contact piece first enters the space below the central arc-inducing part, while the head of the short contact piece enters the space below the lateral arc-inducing part. This ensures that the arc enters the arc extinguishing chamber from the central arc-inducing part and does not move downward along the lateral arc-inducing part, causing breakdown on the short contact piece.

[0005] The purpose of this utility model is achieved as follows: a contact arc-extinguishing system 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 a lateral arc-inducing portion that cooperates with the short contact plates. During the separation of the moving contact and the stationary contact, the arc-inducing head of the long contact plate first enters the space below the central arc-inducing portion, while the head of the short contact plate then enters the space below the lateral arc-inducing portion.

[0006] In a specific embodiment of this utility model, when the moving contact is in the open position, the line connecting the rotation center of the moving contact with the arc-inducing head of the long contact piece and the line connecting the rotation center of the moving contact with the extension end of the middle arc-inducing part form an included angle A; the line connecting the rotation center of the moving contact with the head of the short contact piece and the line connecting the rotation center of the moving contact with the extension end of the lateral arc-inducing part form an included angle B; the included angle A is greater than the included angle B.

[0007] In another specific embodiment of this utility model, the arc-extinguishing chamber further 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 grid plate nearby, 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 middle of the lower edge of the second part.

[0008] In another specific embodiment of this utility model, the lateral arc-drawing portions are a pair, respectively located on both sides of the central arc-drawing portion, the width of the pair of lateral arc-drawing portions is equal, and the width of the central arc-drawing portion is less than or equal to twice the width of the lateral arc-drawing portions.

[0009] In a further specific embodiment of this utility model, the width of the central arc-drawing portion is greater than or equal to the width of the set of long contact pieces, and less than or equal to 2.5 times the width of the set of long contact pieces.

[0010] In a more specific embodiment of this utility model, both the central arc-drawing portion and the lateral arc-drawing portion are flat.

[0011] In yet another specific embodiment of this utility model, the moving arc-inducing plate further includes a bending portion, which is a pair, bending from the side of the second portion away from the first portion toward the direction away from the arc-extinguishing chamber, and the lateral arc-inducing portion extends from the lower edge of the bending portion into the arc-extinguishing chamber, and the lateral arc-inducing portion is a pair.

[0012] In yet 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.

[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, when the moving contact and the stationary contact are not in contact, the long contact piece is tilted relative to the short contact piece toward the stationary contact.

[0015] Because of the above-mentioned structure, this utility model ensures that during the separation of the moving contact and the stationary contact, the arc-initiating head of the long contact piece first enters the space below the middle arc-initiating part, while the head of the short contact piece enters the space below the lateral arc-initiating part. This ensures that the arc enters the arc-extinguishing chamber from the middle arc-initiating part and does not move downward along the lateral arc-initiating part, causing breakdown on the short contact piece. 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 front view 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 three-dimensional schematic diagram of the movable arc-guiding plate described in this utility model; Figure 6 This is a side view of the movable arc-drawing plate described in this utility model; Figure 7 This is a front view of the moving arc plate 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. Bending part; 136. Mounting protrusion; 14. Gas-generating component; 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. Housing; 31. Base; 32. Base 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 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 that the contact piece 21 is electrically connected to 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 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, meaning ten short contact pieces 212 form two groups. Alternatively, four long contact pieces 211 can form one group, and correspondingly, four short contact pieces 212 can form one group.

[0027] like Figure 3 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] like Figure 4 The flared opening is located between the stationary contact and the extended end of the moving arc-inducing plate 13. Alternatively, the flared opening extends from the stationary contact side toward the moving arc-inducing plate 13 and is offset from the moving arc-inducing plate 13. This arrangement allows the electric arc to be concentrated and enters the grid plate 12 through the flared opening; furthermore, the flared opening accelerates airflow, facilitating the rapid entry of the electric arc into the grid plate 12.

[0030] See you later Figure 4 Both the long contact piece 211 and the short contact piece 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 of the long contact piece 211 is also located below the flared opening. That is, the arc contact 214 of both the long contact piece 211 and the short contact piece 212 is located below the flared opening.

[0031] Furthermore, the long contact piece 211 has an extended arc-inducing head 2111. When 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.

[0032] See you later Figures 4 to 7 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, 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. Preferably, both the central arc-inducing part 133 and the lateral arc-inducing part 134 are flat plates.

[0033] Specifically, the movable arc-inducing plate 13 further includes a bending portion 135, which is a pair, respectively disposed on both sides of the central arc-inducing portion 133, bending from the side of the second portion 132 away from the first portion 131 in a direction away from the arc-extinguishing chamber 1. The central arc-inducing portion 133 extends from the lower edge of the second portion 132 into the interior of the arc-extinguishing chamber 1; while the lateral arc-inducing portion 134 extends from the lower edge of the bending portion 135 into the interior of the arc-extinguishing chamber 1, thus creating a height difference between the central arc-inducing portion 133 and the lateral arc-inducing portion 134. Specifically, the central arc-inducing portion 133 is located above the lateral arc-inducing portion 134, while the lateral arc-inducing portion 134 is located below the central arc-inducing portion 133.

[0034] The central arc-inducing portion 133 is configured to cooperate with the long contact piece 211, while the lateral arc-inducing portion 134 is configured to cooperate with the short contact piece 212. Specifically, during the separation of the moving contact 2 from the stationary contact, that is, during the swinging process of the moving contact 2 carrying the long contact piece 211 and the short contact piece 212, the arc-inducing head 2111 of the long contact piece 211 first enters the space below the central arc-inducing portion 133, while the head of the short contact piece 212 then enters the space below the lateral arc-inducing portion 134. This ensures that when an arc is generated on the long contact piece 211, it can smoothly enter the arc-extinguishing chamber 1 along the central arc-inducing portion 133.

[0035] In other words, during the separation of the moving contact 2 from the stationary contact, the long contact piece 211 enters the space below the central arc-inducing section 133 earlier than the short contact piece 212 enters the space below the lateral arc-inducing section 134, with a time difference between the two moments. Within this time difference, the arc is ensured to enter the arc-extinguishing chamber 1 from the central arc-inducing section 133, without moving downwards along the lateral arc-inducing section 134, thereby preventing breakdown on the short contact piece 212.

[0036] In the above embodiment, the bending portion 135 is provided, which further increases the distance between the extension end of the central arc-leading portion 133 and the extension end of the lateral arc-leading portion 134. This arrangement can also prevent the lateral arc-leading portion 134 from being broken down when the electric arc lands on the central arc-leading portion 133.

[0037] Preferably, the lateral arc-drawing portions 134 are in pairs, located on either side of the central arc-drawing portion 133. Similarly, the bending portions 135 are also in pairs, located on either side of the central arc-drawing portion 133. The lateral arc-drawing portions 134 and the bending portions 135 correspond one-to-one.

[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 The width of the central arc-drawing portion 133 is 'a', and the width of the lateral arc-drawing portion 134 is 'b'. The width of the gap formed between the central arc-drawing portion 133 and the lateral arc-drawing portion 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.

[0040] When the arc-extinguishing chamber 1 and the moving contact 2 are installed, and 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.

[0041] 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, while also 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.

[0042] See you later Figure 4 At this time, the moving contact 2 is in the open position. The line connecting the rotation center of the moving contact 2 with the arc-leading head 2111 of the long contact piece 211 and the line connecting the rotation center of the moving contact 2 with the extension end of the middle arc-leading part 133 form an included angle A. Similarly, the line connecting the rotation center of the moving contact 2 with the head of the short contact piece 212 and the line connecting the rotation center of the moving contact 2 with the extension end of the lateral arc-leading part 134 forms an included angle B.

[0043] To optimize arc generation on the long contact piece 211, when the moving contact 2 is not in contact with the stationary contact, the long contact piece 211 is tilted relative to the short contact piece 212 towards the stationary contact. Accordingly, if the included angle A is greater than the included angle B, it ensures that during the separation process between the moving contact 2 and the stationary contact, the arc-initiating head 2111 of the long contact piece 211 can first enter the space below the central arc-initiating portion 133, while the head of the short contact piece 212 enters the space below the lateral arc-initiating portion 134 later.

Claims

1. A contact arc-extinguishing system 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-inducing piece (13) includes a central arc-inducing part (133) that cooperates with the long contact piece (211) and a lateral arc-inducing part (134) that cooperates with the short contact piece (212). During the separation of the moving contact (2) and the stationary contact, the arc-inducing head (2111) of the long contact piece (211) first enters the space below the central arc-inducing part (133), while the head of the short contact piece (212) then enters the space below the lateral arc-inducing part (134).

2. The contact arc extinguishing system of the switch according to claim 1, characterized in that: When the moving contact (2) is in the open position, the line connecting the rotation center of the moving contact (2) and the arc-leading head (2111) of the long contact piece (211) and the line connecting the rotation center of the moving contact (2) and the extension end of the middle arc-leading part (133) form an angle A; the line connecting the rotation center of the moving contact (2) and the head of the short contact piece (212) and the line connecting the rotation center of the moving contact (2) and the extension end of the lateral arc-leading part (134) form an angle B; the angle A is greater than the angle B.

3. The contact arc extinguishing system of the switch according to claim 1, characterized in that: The arc-extinguishing chamber (1) further 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) further 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) close to it, the second part (132) is located below the first part (131) and bends into the interior of the arc-extinguishing chamber (1), and the central arc-inducing part (133) is formed by bending from the middle of the lower edge of the second part (132) into the interior of the arc-extinguishing chamber (1).

4. The contact arc extinguishing system of the switch according to claim 1, characterized in that: The lateral arc-drawing portions (134) are a pair, located on both sides of the central arc-drawing portion (133). The widths of the pair of lateral arc-drawing portions (134) are equal, and the width of the central arc-drawing portion (133) is less than or equal to twice the width of the lateral arc-drawing portions (134).

5. The contact arc extinguishing system of the 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).

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

7. The contact arc extinguishing system of the switch according to claim 3, characterized in that: The moving arc-inducing plate (13) further includes a bending portion (135), which is a pair, bending from the side of the second part (132) away from the first part (131) in a direction away from the arc-extinguishing chamber (1), and the lateral arc-inducing portion (134) extends from the lower edge of the bending portion (135) into the arc-extinguishing chamber (1).

8. The contact arc extinguishing system of the switch according to claim 1, 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.

9. The contact arc extinguishing system of the switch according to claim 3, 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 system of the switch according to claim 1, characterized in that: When the moving contact (2) is not in contact with the stationary contact, the long contact piece (211) is tilted toward the stationary contact relative to the short contact piece (212).

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