Contact arcing device for frame switches

Abstract

The utility model discloses a contact arc extinguishing device of frame switch, including arc extinguishing chamber, contact subassembly, static contact, bottom plate and base, contact subassembly includes contact support, main contact piece, arc contact piece, side plate, shaft and insulating part, and the main contact piece is located arc contact piece both sides, and the hole of passing through the shaft is seted up on main contact piece, arc contact piece and side plate, and the first silver point has on the first blade of arc contact piece, and the second silver point has on the second blade on main contact piece, and the first blade is longer than the second blade, and arc extinguishing chamber includes louver, first insulating part, second insulating part, first side plate and cover, and the end of second insulating part has the baffle, and second insulating part is located arc contact piece both sides, and the groove is seted up on contact support, and the notch is seted up on insulating part, and the baffle inserts the groove and notch, and static contact includes the body, and the first static silver point of contact with second silver point has on the body, and the second static silver point of contact with first silver point has, the utility model improves arc extinguishing chamber narrow slit arc extinguishing effect and insulation performance.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, and in particular to an arc-extinguishing device for the contacts of a frame switch. Background Technology

[0002] Currently, in existing low-voltage devices, second-generation DC isolation frame switches all adopt a 2P structure, which uses an arc contact plus a main contact scheme. The arc contact uses a narrow slit arc extinguishing method, which elongates the arc while using the narrow slit effect to squeeze the arc and burn the gas-generating material on the side of the arc contact to extinguish the arc. However, the voltage of existing isolation switches can only be DC 1500V, and the usage category adopts PVO parameters.

[0003] With increasing market competition, the application category has been upgraded to DC-22A / 23A, the time constant under rated short-circuit making capacity test has become longer, and the rated voltage is also increasing towards DC2000V. During the breaking process of the disconnecting switch, with the increase in voltage and arc energy, the existing disconnecting switch structure has a small gap between the main arc contacts due to space limitations. At the same time, the free metal particles generated during the breaking process and the carbonized molecular materials released by the gas-generating materials at high temperature are adsorbed on the insulating parts, which further causes the arc to surge from the arc contact to the main contact, making breaking difficult.

[0004] The existing structure has the following problems:

[0005] (1) The rated short-circuit breaking capacity test fails due to the use of a different category or voltage; due to space limitations, the arc-extinguishing chamber in the existing structure has limited space, resulting in a low arc voltage in the arc-extinguishing chamber, which is insufficient to quickly break the arc. During the breaking process, the arc is followed by a series of arcs, and the arc cannot be completely led to the arc contact.

[0006] (2) The arc contact separates later than the main contact. In the original structure, the main arc contact is present on the arc contact plate at the same time, which causes the time interval between the main arc contact to be too small. The voltage of the main contact has not completely disappeared before the arc contact starts to break, causing the main contact to also bear the arc.

[0007] (3) When the voltage of the application is increased to DC2000V, it is necessary to further improve the insulation performance. However, due to space limitations, the existing structure has a very close distance between the arc contact and the main contact. Neither the air gap nor the creepage distance can meet the requirements of DC2000.

[0008] (4) The arc contacts of the original structure are distributed on the edges of the insulating parts on both sides of the arc extinguishing chamber, which cannot produce the narrow gap effect; at the same time, since the rear end of the arc contact is an open structure, it is very easy for the airflow to run back during the breaking process, driving the main contacts connected by the arc. Utility Model Content

[0009] Purpose of the utility model: To address the shortcomings of existing technologies, this utility model proposes a contact arc-extinguishing device for a frame switch. While increasing the arc voltage in the arc-extinguishing chamber, it solves the problem of ineffective and timely disconnection during arc breaking, prevents back-contact issues during arc breaking, improves the reliability of the arc contact separating from the main contact, further enhances the arc-extinguishing effect and insulation performance of the narrow slot in the arc-extinguishing chamber, and thus improves the connection and disconnection capabilities of the isolating switch.

[0010] Technical solution: The contact arc extinguishing device of the frame switch of this utility model includes an arc extinguishing chamber, a contact assembly, a stationary contact, a base plate and a base;

[0011] The contact assembly includes a contact support, a main contact piece, an arc contact piece, a side plate, a shaft, and an insulating component; the main contact piece is located on both sides of the arc contact piece, and holes through the shaft are formed in the main contact piece, the arc contact piece, and the side plate; the insulating component and the side plate are fixed to the contact support; a first silver dot is on the first blade of the arc contact piece, and a second silver dot is on the second blade of the main contact piece, and the length of the first blade is longer than that of the second blade;

[0012] The arc-extinguishing chamber includes a grid plate, a first insulating element, a second insulating element, a first side plate, and a cover plate; the end of the second insulating element has a baffle, and the second insulating element is located on both sides of the arc contact piece; the contact support has a groove, the insulating element has a slot, and the baffle is inserted into the groove and the slot;

[0013] The stationary contact includes a body, on which there is a first stationary silver point that contacts the second silver point, and a second stationary silver point that contacts the first silver point.

[0014] The first side plate has slots for inserting grid plates, and the protrusions on the grid plates are inserted according to the position of the slots on the first side plate.

[0015] The main body has a slot for inserting the first blade, thereby avoiding the first blade.

[0016] The baffle has a first arc surface, and the groove has an arc surface. The first arc surface and the arc surface on the groove are concentric.

[0017] The second insulating element has a notch for engaging with the first insulating element.

[0018] The baffle has a second arc surface, and the slot of the insulating component has a third arc surface. The second arc surface and the third arc surface are concentric.

[0019] A first notch is provided on the side plate for inserting the first insulating element, thereby connecting the first insulating element to the side plate.

[0020] The baffle and the second insulating component are integrally formed to enhance the sealing effect of the arc-extinguishing chamber.

[0021] The arc contact piece is located in the middle of the contact assembly.

[0022] The cover plate has protrusions that snap into the side plate, making it easy to connect the cover plate to the side plate.

[0023] Working Principle: The baffle extending from the insulating component on the arc-extinguishing chamber of this invention is directly inserted between the contact support and the insulating component in the contact assembly. The clearance space of the contact support and insulating component on the contact assembly matches the shape of the baffle, forming an effective barrier. While maintaining the same size of the arc-extinguishing chamber, the spacing between the grid plates is shortened, increasing the number of grid plates within the same space. An integrated insulating component with a baffle is fixed parallel to both sides of the arc-extinguishing chamber. After the disconnecting switch is assembled, the baffle extending from the insulating component is inserted into the middle of the moving contact piece, as well as into the contact support and insulating component of the moving contact, forming a seal.

[0024] The moving contact assembly fits into the arc surface on the base plate and the base. After assembly, there is only a small gap even during movement. Together, they form the sealing structure at the lower end of the arc-extinguishing chamber, which effectively blocks the backflow of airflow when the arc is broken.

[0025] The arc contact piece is longer than the main contact pieces on both sides. There is only one arc silver point on the arc contact, while the silver point of the stationary contact is separated from the middle, corresponding to the silver point of the moving contact to form a connection and disconnection. The arc silver point separates later than the main silver point, and the arc is completely led to the arc contact piece. The area separated in the middle of the stationary contact passes through the baffle of the arc-extinguishing chamber insulation component. After the frame switch is assembled, the arc contact piece is surrounded by the arc-extinguishing chamber insulation component in a narrow space. The entire arc-starting area is only open in the direction of the arc-extinguishing chamber, which further enhances the air blowing effect during the arc extinguishing process. Due to the presence of the baffle, the insulation performance of the arc contact piece and the main contact piece is increased.

[0026] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0027] (1) This utility model improves the arc voltage during arc breaking by adding the arc-extinguishing chamber grid plate on the basis of the existing structure.

[0028] (2) The present invention sets a baffle through the base and the stationary contact extends into the middle of the contact support of the moving contact, which extends the narrow slit length of the arc contact. At the same time, the sealing of the rear end enhances the effect of arc extinguishing gas blowing, further preventing the arc from following the airflow and forming a short circuit of the main contact, thus improving the reliability of the test. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the circuit breaker assembly in this embodiment of the utility model;

[0030] Figure 2 This is a schematic diagram of the arc-extinguishing chamber structure of this utility model;

[0031] Figure 3This is a schematic diagram of the contact structure of this utility model;

[0032] Figure 4 This is a schematic diagram illustrating the interaction between the contact structure and the stationary contact of this utility model.

[0033] Figure 5 This is a schematic diagram showing the assembly relationship between the contact structure, the arc-extinguishing chamber, and the mechanism of this utility model.

[0034] Figure 6 A top view showing the interaction between the contact structure and the insulating component of the arc-extinguishing chamber in this utility model;

[0035] Figure 7 This is a cross-sectional view showing the interaction between the contact structure and the insulating component of the arc-extinguishing chamber in this utility model. Detailed Implementation

[0036] like Figure 1 As shown, the contact arc extinguishing device of the frame switch of this utility model includes an arc extinguishing chamber 1, a contact assembly 2, a stationary contact 3, a base plate 4, and a base 5.

[0037] like Figure 2 As shown, the arc-extinguishing chamber 1 includes a grid plate 11, a first insulating member 12, a second insulating member 13, a first side plate 14, and a cover plate 15. During assembly, the boss 121 of the first insulating member 12 is first inserted into the notch 131 of the second insulating member 13 for fixation. In Figure 2, the insulating members on the side of the arc-extinguishing chamber 1 are assembled in a left-right mirror image.

[0038] After the first insulating component 12 and the second insulating component 13 are assembled into a whole component, the boss 122 of the first insulating component 12 is inserted into the first notch 142 of the first side plate 14. Then, the bosses 111 on the grid plate 11 are assembled and inserted one by one according to the position of the slot 143 of the first side plate 14. At the same time, the notch 144 of the first side plate 14 is inserted into the boss 151 of the cover plate 15. After all the parts are assembled, the bosses of all the grid plates are deformed and pressed into the notch of the first side plate 14 by riveting, thus forming an arc-extinguishing chamber 1.

[0039] In this embodiment, the arc voltage of the switch is increased by increasing the number of grid plates 11. That is, by adjusting the spacing of the rows of slots 143 on the first side plate 14, the number of grid plates is increased from the original 32 to the current 39.

[0040] like Figure 3 As shown, the contact assembly 2 includes an SMC-pressed contact support 21, a main contact piece 22, an arc contact piece 23, a side plate 24, a shaft 26, and an insulator 25. From Figure 3Two arc contact pieces 23 are centrally located. There are five main contact pieces 22 on each side. All contact pieces have a circular hole 2221 in the same position in the middle. The shaft 26 passes through the circular hole, and the main contact pieces 22 and arc contact pieces 23 rotate around the center of the shaft 26.

[0041] During assembly, the boss 261 of the shaft 26 engages with the round holes 241 of the two side plates 24, and the two side plates 24 are then fixed to the contact support 21 with screws for positioning. Similarly, the insulating part 25 is assembled to the contact support 21 and fixed by screws passing through the hole 251. The contact assembly 2 rotates around the center 241 of the side plate 24 under the drive of the switching mechanism.

[0042] An arc contact piece 23 is installed in the center, and main contact pieces 22 are installed on both sides. A first blade 232 on the arc contact piece 23 is welded with a first silver point 231, and a second blade 222 on the main contact piece 22 is welded with a second silver point 221. The first blade 232 is longer than the second blade 222, and the welding position of the first silver point 231 is closer to the arc-extinguishing chamber than the silver point 221. In this embodiment, the first blade 232 and the second blade 222 are copper sheets.

[0043] like Figure 4 As shown in the figure, the stationary contact 3 is welded to the body 33 by the first stationary silver point 31 and the second stationary silver point 32, and the body 33 is made of copper block.

[0044] Figure 4 In the open position of the switch, the contact assembly 2 is first driven by the switching mechanism to rotate counterclockwise. During the closing process, the first silver point 231 on the arc contact piece 23 first contacts the second stationary silver point 32 on the stationary contact 3, and then the second silver point 221 on the main contact piece 22 contacts the first stationary silver point 31. The slot 331 on the stationary contact 3 in the figure is to avoid the first blade 232 on the arc contact piece 23 in the closed position. If the contact assembly 2 rotates clockwise to open the switch, the second silver point 221 separates first, and then the first silver point 231 separates, which is exactly the opposite of the closing sequence. The time difference between the first and second silver points is 2.5 to 3.5 ms.

[0045] In the actual process of breaking the arc during the switch opening, the arc contact piece 23 breaks later than the main contact piece 22, and the arc is completely borne by the arc contact piece 23. Compared with the original structure where there is a second silver point 221 on the arc contact piece, the first silver point 231 in the existing structure is farther away from the second silver point 221, and the time difference before and after the opening is longer (the time difference is 2ms), which reduces the risk of the arc remaining on the main contact piece 22 and improves the reliability of the breaking.

[0046] like Figure 5 , Figure 6As shown, the baffle 133 on the second insulating member 13 on the arc-extinguishing chamber is directly inserted into the groove 211 on the contact support 21 on the contact assembly 2; at the same time, the baffle 133 is also inserted into the slot 252 on the insulating member 25 on the contact assembly 2.

[0047] like Figure 7 As shown, the two arc contact pieces 23 in the contact assembly 2 are isolated by the second insulating member 13. Figure 7 In the middle area, the baffle 133 of the second insulating element 13 forms a block between the main contact piece 22 and the arc contact piece 23, increasing the creepage distance between the contact pieces. For the contact assembly 2 and the stationary contact 3, the arc generated when the switch is disconnected is concentrated on the arc contact piece 23. The second insulating element 13 is distributed on both sides of the arc contact piece, forming a very small narrow space. During the arc breaking process, the arc is entirely in a semi-enclosed space formed by the left and right second insulating elements 13, the base 5, and the bottom plate 4. The high temperature of the arc generated during the switch breaking process will cause the first insulating element 12 and the second insulating element 13 in the arc-extinguishing chamber 1 to generate gas. Since there are parts blocking the space around and at the rear, the gas can only flow towards the top of the arc-extinguishing chamber, driving the arc to move faster to the middle of the arc-extinguishing chamber grid, further improving the arc-extinguishing effect of the narrow slot of the arc-extinguishing chamber.

[0048] The clearance fit of the parts in this utility model is referenced. Figure 7 The baffle 133 extending from the second insulating member 13 has a first arc surface 1331 and a second arc surface 1332. The arc surface 211 of the groove 211 on the contact support 21 is concentric with the arc surface 1331 of the second insulating member 13. Similarly, the second arc surface 1332 on the second insulating member 13 is concentric with the third arc surface 2521 of the slot 252 on the insulating member 25. They are in a clearance fit. During the rotation of the contact 2, the contact support 21 and the insulating member 25 rotate synchronously, forming a concave-convex clearance fit with the arc trajectory of the second insulating member 13. This structure makes the fit gap smaller, preventing the arc from transferring from the arc contact piece 23 to the main contact piece 22.

Claims

1. A contact arc-extinguishing device for a frame switch, characterized in that: It includes an arc-extinguishing chamber (1), a contact assembly (2), a stationary contact (3), a base plate (4), and a base (5); The contact assembly (2) includes a contact support (21), a main contact piece (22), an arc contact piece (23), a side plate (24), a shaft (26), and an insulating component (25); the main contact piece (22) is located on both sides of the arc contact piece (23), and the main contact piece (22), the arc contact piece (23), and the side plate (24) are provided with holes through the shaft (26); the insulating component (25) and the side plate (24) are fixed on the contact support (21); the first blade (232) on the arc contact piece (23) has a first silver point (231), and the second blade (222) on the main contact piece (22) has a second silver point (221), and the length of the first blade (232) is longer than that of the second blade (222); The arc-extinguishing chamber (1) includes a grid plate (11), a first insulating element (12), a second insulating element (13), a first side plate (14), and a cover plate (15); the end of the second insulating element (13) has a baffle (133), and the second insulating element (13) is located on both sides of the arc contact piece (23); the contact support (21) has a groove (211), the insulating element (25) has a slot (252), and the baffle (133) is inserted into the groove (211) and the slot (252); The stationary contact (3) includes a body (33) having a first stationary silver point (31) that contacts the second silver point (221) and a second stationary silver point (32) that contacts the first silver point (231).

2. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The first side plate (14) has slots (143) for inserting grid plates (11).

3. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The main body (33) has a slot (331) for inserting the first blade (232).

4. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The baffle (133) has a first arc surface (1331), and the groove (211) has an arc surface. The first arc surface (1331) and the arc surface on the groove (211) are concentric.

5. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The second insulating member (13) has a notch (131) for engaging the first insulating member (12).

6. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The baffle (133) has a second arc surface (1332), and the slot (252) of the insulating component has a third arc surface (2521). The second arc surface (1332) and the third arc surface (2521) are concentric.

7. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The first side plate (14) has a first notch (142) for inserting the first insulating member (12).

8. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The baffle (133) is integrally formed with the second insulating component (13).

9. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The arc contact piece (23) is located in the middle of the contact assembly (2).

10. The contact arc-extinguishing device of the frame switch according to claim 1, characterized in that: The cover plate (15) has a protrusion (151) that engages with the first side plate (14).

Images