A contact arc-extinguishing structure for a switch

Abstract

An arc-extinguishing structure for a switch contact belongs to the field of low-voltage electrical technology. It includes a contact system and an arc-extinguishing chamber located on the opening side of the contact system. The contact system includes contact pieces, including a short contact piece and a long contact piece. The short contact piece has a first arc contact and a first main contact, while the long contact piece has a second arc contact and a second main contact. In the extending direction of the contact pieces, the long contact piece also has an arc-initiating head that extends beyond the short contact piece. Advantages: It improves the arc-initiating capability of the moving contact while ensuring short-term withstand capability and operational reliability.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical technology, specifically relating to a contact arc-extinguishing structure 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, there are moving contacts with the same contact length, each of which is provided with a main contact and an arc contact. Although they have a large short-term withstand capability and operational reliability, they lack the ability to guide the arc to enter the arc-extinguishing chamber quickly due to the absence of long contact pieces. Utility Model Content

[0004] The purpose of this utility model is to provide a contact arc-extinguishing structure for a switch, which ensures the short-term withstand capability and operational reliability of the contact system by setting a first arc contact and a first main contact on a short contact piece, and setting a second arc contact and a second main contact on a long contact piece; at the same time, by having an arc-inducing head on the long contact piece that extends beyond the short contact piece in the extension direction of the contact piece, the ability of the moving contact to quickly introduce the arc into the arc-extinguishing chamber is improved.

[0005] The purpose of this utility model is achieved as follows: a contact arc-extinguishing structure for a switch includes a contact system and an arc-extinguishing chamber located on one side of the contact system in the opening direction. The contact system includes contact pieces, which include a short contact piece and a long contact piece. The short contact piece has a first arc contact and a first main contact, and the long contact piece has a second arc contact and a second main contact. In the extending direction of the contact pieces, the long contact piece also has an arc-inducing head that extends beyond the short contact piece.

[0006] In a specific embodiment of this utility model, after the short contact piece and the long contact piece are installed, the first arc contact point and the second arc contact point are flush in the extending direction of the contact piece.

[0007] In another specific embodiment of this utility model, after the short contact piece and the long contact piece are installed, the first main contact point and the second main contact point are flush in the extension direction of the contact piece.

[0008] In another specific embodiment of this utility model, the arc-initiating head is located on one side of the second arc contact facing the swing end of the long contact piece.

[0009] In another specific embodiment of this utility model, the height of the arc-drawing head is 12 mm to 20 mm.

[0010] In a further specific embodiment of this utility model, the arc-inducing head is sickle-shaped and extends curved toward the back of the long contact piece, and the surface of the arc-inducing head facing the stationary contact is an arc surface.

[0011] In a further specific embodiment of this utility model, the arc-extinguishing chamber includes a pair of side plates, multiple grid plates disposed between the pair of side plates, and a pair of gas-generating elements. The multiple grid plates are spaced apart from each other, and the pair of gas-generating elements are respectively located at the lower edge of the grid plates and respectively wrap around the pair of grid plate legs of the grid plates. The pair of gas-generating elements are arranged opposite to each other and form a flared mouth with a gradually decreasing diameter in the upward direction. The arc-initiating head is inserted into the flared mouth, or the arc-initiating head passes through the flared mouth and then protrudes out of the flared mouth.

[0012] In yet another specific embodiment of this utility model, the first arc contact and the second arc contact are located outside the horn opening.

[0013] In yet another specific embodiment of this utility model, the long contact piece is centered, while the short contact pieces are located on both sides of the long contact piece, and the long contact piece separates from the stationary contact of the contact system later than the short contact piece.

[0014] In a further specific embodiment of this utility model, the long contact pieces are arranged in a group of four, while the short contact pieces are arranged in two groups, each group consisting of four pieces, with the two groups of short contact pieces located on both sides of a group of long contact pieces.

[0015] Due to the above-mentioned structure, this utility model has the following advantages: it sets the first arc contact and the first main contact on the short contact piece, and sets the second arc contact and the second main contact on the long contact piece, thereby ensuring the short-term withstand capability and operational reliability of the contact system; at the same time, by having an arc-initiating head on the long contact piece that is higher than the short contact piece in the extension direction of the contact piece, it improves the ability of the moving contact to quickly introduce the arc into the arc-extinguishing chamber. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the switch in this utility model; Figure 2 This is a three-dimensional schematic diagram of the moving contact and one side of the arc-extinguishing chamber in this utility model; Figure 3 This is a three-dimensional schematic diagram of the moving contact and the other side of the arc-extinguishing chamber in this utility model; Figure 4 This is a frontal schematic diagram of the cooperation between the moving contact and the arc-extinguishing chamber in this utility model; Figure 5 This is a partial explosion diagram of the arc-extinguishing chamber in this utility model; Figure 6 This is a partial schematic diagram of the moving contact in this utility model.

[0017] In the diagram: 1. Arc-extinguishing chamber, 11. Side plate, 12. Grid plate, 13. Moving arc-starting plate, 14. Gas-generating component, 15. Arc-extinguishing cover, 16. Anti-freezing bracket; 2. Moving contact, 21. Contact piece, 211. Short contact piece, 2111. First arc contact, 2112. Second arc contact, 212. Long contact piece, 2121. Second arc contact, 2122. Second main contact, 22. Contact support, 221. Separating rib, 222. Insulating diaphragm; 3. Shell, 31. Base, 32. Bottom plate; 100. Partition plate; 200. Arc-starting head; 300. Trumpet mouth. 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 , Figure 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). 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 , Figure 3 , Figure 4 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). 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 frame-shaped and houses the filter unit of the deionization component. 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] 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. Preferably, the gas-generating elements cover a pair of grid plate legs of the grid plate 12. The pair of gas-generating elements 14 are arranged opposite to each other and form a flared opening 300 with a reduced diameter in the upward direction, that is, the flared opening 300 is wider at the bottom and narrower at the top. The flared opening 300 refers to the portion that tapers in both directions in the upward direction, and does not include a straight portion with a constant width or an enlarged portion with a gradually increasing width in the upward direction.

[0026] The above-described configuration allows the electric arc to be focused and enters the grid plate 12 through the flared opening 300. Furthermore, the flared opening accelerates airflow, facilitating the rapid entry of the electric arc into the grid plate 12.

[0027] See you later Figure 3 , Figure 4 The moving contact 2 includes multiple contact pieces 21 arranged side-by-side. Each contact piece 21 includes short contact pieces 211 and long contact pieces 212. Specifically, the long contact pieces 212 have a greater extension length than the short contact pieces 211. Preferably, the long contact pieces 212 are centered, while the short contact pieces 211 are located on either side of the long contact pieces 212. In this embodiment, more specifically, four long contact pieces 212 form a group, and two groups of four short contact pieces 211 are arranged on either side of one group of long contact pieces 212.

[0028] The short contact piece 211 has a first arc contact 2111 and a first main contact 2112. Similarly, the long contact piece 212 has a second arc contact 2121 and a second main contact 2122. After the short contact piece 211 and the long contact piece 212 are installed, the first arc contact 2111 and the second arc contact 2121 are flush in the extension direction of the contact piece 21. Similarly, preferably, the first main contact 2112 and the second main contact 2122 are flush in the extension direction of the contact piece 21. In this utility model, both the long contact piece 212 and the short contact piece 211 are defined as arc contacts, and both have the function of arc generation. The stationary contact head is provided with a stationary main contact (not shown) that cooperates with the first main contact 2112 and the second main contact 2122. Meanwhile, the stationary contact also has a stationary arc contact (not shown) that engages with the second arc contact 2121, and the stationary arc contact also engages with at least one of the first arc contacts 2111.

[0029] This invention ensures the short-term withstand capability and operational reliability of the switch by having a first arc contact 2111 and a first main contact 2112 on the short contact piece 211, and a second arc contact 2121 and a second main contact 2122 on the long contact piece 212. At the same time, in the extension direction of the contact piece 21, the long contact piece 212 also has an arc-inducing head 200 that is higher than the short contact piece 211, thereby improving the ability of the moving contact 2 to quickly introduce the arc into the arc-extinguishing chamber.

[0030] Compared with the prior art, the above-mentioned setting reduces the lever arm of the long contact 212 when it collides with the stationary contact when the moving contact 2 closes, by moving the second arc contact 2121 on the long contact 212 to a position flush with the first arc contact 2111 on the short contact 211. This prevents the long contact 212 from breaking or deforming.

[0031] Secondly, the short contact 211 is provided with the first arc contact 2111. When a large current is interrupted, if the short contact 212 is broken down, the presence of the first arc contact 2111 can greatly improve the burn-resistant performance of the short contact 211, thereby improving the life of the contact system.

[0032] Preferably, the overtravel of the long contact 212 is less than that of the short contact 211, meaning the long contact 212 separates from the stationary contact later than the short contact 211. Therefore, when interrupting a small current, the arc is generated only on the long contact 212. However, when interrupting a large current, the arc is generated on both the long contact 212 and the short contact 211. In other words, the long contact 212 has the function of closing first and then opening later compared to the short contact 211.

[0033] The long contact piece 212 also has an arc-inducing head 200, which refers to the portion of the long contact piece 212 that is higher than the short contact piece 211. Preferably, for the long contact piece 212, the arc-inducing head 200 is located on one side of the second arc contact point 2121 toward the swing end of the long contact piece 212.

[0034] See Figure 4 Preferably, the arc-drawing head 200 is sickle-shaped and extends curved toward the back of the long contact piece 212.

[0035] Specifically, the height H of the arc-starting head 200 is 7 mm to 20 mm. More preferably, the height of the arc-starting head 200 is 12 mm to 20 mm. The above range is the preferred range obtained through multiple experimental verifications.

[0036] More specifically, the surface of the arc-initiating head 200 facing the stationary contact is an arc surface, which facilitates the upward movement of the electric arc along the arc surface.

[0037] The arc-initiating head 200 extends into the flared opening 300, or passes through the flared opening 300 and then extends out of it. Therefore, the arc-initiating head 200 can guide the arc to quickly enter the flared opening 300, or guide the arc to quickly pass through the flared opening 300. Simultaneously, the first arc contact 2111 and the second arc contact 2121 are located outside the flared opening 300.

[0038] like Figure 5 A partition 100 is also provided on the inner side of the side plate 11. The partition 100 is clamped between the side plate 11 and the grid plate 12.

[0039] like Figure 6 This is a schematic diagram showing the contact piece 21 mounted on the contact support 22. The contact support 22 has two spacer ribs 221. The contact piece 21 has insulating spacers 222 on both sides, and the spacer ribs 221 are located between the contact piece 21 and the insulating spacers 222.

Claims

1. A contact arc extinguishing structure of a switch, comprising a contact system and an arc chamber (1) located on the side of the opening direction of the contact system, the contact system comprising a contact piece (21), the contact piece (21) comprising a short contact piece (211) and a long contact piece (212), characterized in that, The short contact (211) has a first arc contact (2111) and a first main contact (2112), and the long contact (212) has a second arc contact (2121) and a second main contact (2122); the long contact (212) further has an arc striking head (200) higher than the short contact (211) in the extension direction of the contact (21).

2. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: After the short contact (211) and the long contact (212) are installed, the first arc contact (2111) is flush with the second arc contact (2121) in the extension direction of the contact (21).

3. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: After the short contact (211) and the long contact (212) are installed, the first main contact (2112) is flush with the second main contact (2122) in the extension direction of the contact (21).

4. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The arc striking head (200) is located on the side of the second arc contact (2121) towards the swing end of the long contact (212).

5. An arc quenching contact structure for a switch as claimed in claim 4, characterized in that: The height of the arc striking head (200) is 12-20 mm.

6. An arc quenching contact structure for a switch as defined in claim 4, characterized in that: The arc striking head (200) is in the shape of a sickle, which bends towards the back of the long contact (212), and the surface of the arc striking head (200) towards the side of the stationary contact is a circular arc surface.

7. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The arc extinguishing chamber (1) comprises a pair of side plates (11), a plurality of fins (12) arranged between the pair of side plates (11), and a pair of gas generating members (14), the plurality of fins (12) are arranged at intervals, the pair of gas generating members (14) are respectively located at the lower edges of the fins (12) and wrap a pair of fin legs of the fins (12), the pair of gas generating members (14) are oppositely arranged and form a horn (300) with gradually decreasing caliber in the upward direction; the arc striking head (200) is inserted into the horn (300), or the arc striking head (200) passes through the horn (300) and then protrudes out of the horn (300).

8. An arc quenching contact structure for a switch as claimed in claim 7, characterized in that: The first arc contact (2111) and the second arc contact (2121) are located outside the horn (300).

9. An arc quenching contact structure for a switch as defined in claim 1, characterized in that: The long contact (212) is in the center, and the short contact (211) is located on both sides of the long contact (212), and the long contact (212) is separated from the stationary contact of the contact system later than the short contact (211).

10. An arc quenching contact structure for a switch as claimed in claim 9, characterized in that: The long contact (212) is four in a group, and the short contact (211) has two groups, each group including four, and the two groups of short contacts (211) are located on both sides of a group of long contacts (212).

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