An interlocking device for a circuit breaker

Abstract

This utility model discloses an interlocking device for a circuit breaker, belonging to the field of medium-voltage switch technology. The device has a top plate fixed inside the cabinet door, with a top plate hole at the end of the top plate. A guide pin is mounted on the frame via an extension bracket, with a pin hole at the end of the extension bracket. A locking pin is fixed on the interlocking plate. When the cabinet door is closed, the top plate pushes the guide pin inward, aligning the top plate hole with the pin hole. When the limit pin moves to the interlocking position, it drives the locking pin into the pin hole and the top plate hole, preventing the cabinet door from opening. When the limit pin moves to the unlocking position, it drives the locking pin out of the pin hole and the top plate hole, and the guide pin pushes the top plate outward, misaligning the top plate hole and the pin hole, allowing the cabinet door to open. This utility model, through the circuit breaker's own interlocking mechanism, requires workers to operate according to the interlocking procedure during maintenance. When combined with the transformer substation door interlock, the door cannot be opened while energized, resulting in higher reliability.

Description

Technical Field

[0001] This utility model relates to electrical equipment, specifically to a circuit breaker interlocking device in the field of medium-voltage switch technology. Background Technology

[0002] When the circuit breaker is operating in the transformer substation, the grounding switch is in the open position. If workers need to perform maintenance in this state, live operation is strictly prohibited. To prevent worker misoperation and ensure equipment safety, the transformer substation door must not be opened. Maintenance can only be performed when the circuit breaker grounding switch is closed. After maintenance is completed, the door must be closed before the grounding switch can be opened to ensure operational safety.

[0003] The existing technical solution mainly uses a lever mechanism, which connects the cabinet door to the crank arm on the circuit breaker mechanism through an intermediate rod. The cabinet door has a square groove, and the intermediate rod is connected to an L-shaped plate. A thin plate is installed on the L-shaped plate. If the worker needs to perform maintenance, he must push the L-shaped plate upwards to open the door. When the thin plate does not interfere with the square groove of the cabinet door, the cabinet door can be opened.

[0004] Opening the cabinet door requires lifting it to a certain height before it can rotate open. Current technology may pose a risk of workers operating the equipment while it is electrified, or of personnel misoperating during operation; therefore, risks still exist. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this utility model provides a circuit breaker interlocking device with a simple structure and high safety and reliability. The technical solution of this device is as follows.

[0006] An interlocking device for a circuit breaker is disclosed. The circuit breaker is mounted on a frame inside a cabinet door. A panel is installed on the frame, and an interlocking plate is movably installed on the rear side of the panel. A limit pin is set on the interlocking plate, and the limit pin moves between several limited positions on the panel to achieve interlocking protection of the circuit breaker. A top plate is provided on the inner side of the cabinet door, and a top plate hole is provided at the end of the top plate. A guide pin is installed on the frame through an extension bracket, and a pin hole is provided at the end of the extension bracket. An interlocking pin is provided on the interlocking plate. When the cabinet door is closed, the top plate pushes the guide pin inward, so that the top plate hole and the pin hole are aligned. When the limit pin moves to the interlocking position, it drives the interlocking pin to insert into the pin hole and the top plate hole, and the cabinet door cannot be opened. When the limit pin moves to the unlocking position, it drives the interlocking pin to be pulled out from the pin hole and the top plate hole, and the guide pin pushes the top plate outward, so that the top plate hole and the pin hole are misaligned, and the cabinet door is opened.

[0007] Furthermore, a curved plate is installed on the cabinet door using bolts, and the curved plate is fixed to the top plate using bolts.

[0008] Furthermore, the interlocking bend plate is bolted to the interlocking plate, and the interlocking pin is bolted to the end of the interlocking bend plate.

[0009] Furthermore, the extension support is a curved plate.

[0010] Furthermore, the guide pin extends from the end of the bent plate, and a compression spring is fitted on the guide pin. The rear end of the compression spring contacts the fixed pin, and the front end contacts the stepped surface on the guide pin.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1) This utility model uses the circuit breaker's own interlocking mechanism, which requires workers to operate according to the interlocking procedure during maintenance. When combined with the transformer substation door for interlocking, the door cannot be opened when the power is on, thus improving reliability. 2) This utility model achieves interlocking by having the ejector installed on the cabinet door blocked by a chain pin, resulting in a simple and reliable structure; 3) This utility model is simple to assemble, and its installation and maintenance are relatively simple. Attached Figure Description

[0012] Figure 1 This is a three-dimensional structural diagram of the interlocking device; Figure 2 This is a schematic diagram showing the installation positions of the panel and the interlocking plate; Figure 3 This is a schematic diagram of the panel and interlocking plate structure; Figure 4 This is a structural diagram of some parts; Figure 5 This is a diagram showing the position of the interlocking plate when the cabinet door is opened; Figure 6 This is a schematic diagram of the interlocking structure when the cabinet door is opened; Figure 7 This is a diagram showing the position of the interlocking plate when the cabinet door is closed; Figure 8 This is a schematic diagram of the interlocking structure when the cabinet door is closed.

[0013] The diagram is labeled as follows: 1 is the cabinet door; 2 is the interlocking curved plate; 3 is the bolt; 4 is the interlocking pin; 5 is the curved plate; 6 is the top plate; 6-1 is the hole; 6-2 is the hole; 7 is the extension bracket; 7-1 is the hole; 7-2 is the hole; 7-3 is the hole; 8 is the compression spring; 9 is the fixing pin; 10 is the guide pin; 11 is the panel; 12 is the interlocking plate; 12-1 is the limit pin; 13 is the frame; 14 is the step surface. Detailed Implementation

[0014] The technical solution of this utility model will be further explained below with reference to the accompanying drawings.

[0015] The circuit breaker is installed on a frame 13 inside the cabinet door 1. A panel 11 is installed on the frame 13, and a movable interlocking plate 12 is installed on the rear side of the panel 11. A limit pin 12-1 is installed on the interlocking plate 12, and the limit pin 12-1 can move between several limited positions on the panel 11. By moving the limit pin 12-1, the interlocking plate 12 can be moved, thereby realizing the protection or disconnection protection of the circuit breaker.

[0016] The assembly diagram of the interlocking device in this implementation example is as follows: Figure 1 and Figure 2 As shown, the specific structure of some parts is as follows: Figure 3 Figure 4 As shown.

[0017] The curved plate 5 is fixed to the cabinet door 1 with bolts. The waist hole 6-1 on the top plate 6 is fixed to the curved plate 5 with bolts. The curved plate 5 and the top plate 6 can move together with the opening and closing of the cabinet door 1. The interlocking curved plate 2 is fixed to the interlocking plate 12 with bolts. The interlocking pin 4 is fastened to the interlocking curved plate 2 with bolts 3. The extension bracket 7 is welded to the frame 13. One end of the fixing pin 9 is threaded and passes through the hole 7-3 on the extension bracket 7 and is fixed with a nut. One end of the guide pin 10 passes through the hole 7-2 on the extension bracket 7, and the other end near the contact surface of the compression spring passes through the hole 9-1 on the fixing pin 9. The compression spring 8 contacts one end face of the fixing pin 9 and the stepped surface 14 of the guide pin 10. After installation, there is a certain preload to ensure that the compression spring 8 can quickly drive the guide pin 10 to the designated position when the cabinet door 1 is opened.

[0018] Door opening procedure: see Figure 5 , Figure 6 If the transformer substation needs to be opened, first follow the instructions regarding the circuit breaker's own interlocking mechanism. Figure 3 The operation proceeds in the order of 4, 3, 2, and 1 on the upper panel 11, with the 12-1 limit pin on the interlocking plate acting as a limit. First, when the limit pin is in position 4, the circuit breaker needs to be tripped. Then, the 12-1 limit pin is moved upwards to position 3. At this point, the isolating switch needs to be opened to further unlock the circuit breaker interlock and proceed to the next step. The 12-1 limit pin is then moved to position 2. At this point, the grounding switch needs to be closed to prevent injury from a live circuit breaker. Finally, the 12-1 limit pin is moved to position 1. The interlocking pin 4 then moves upwards along with the interlocking plate 12, and then moves upwards along the 7-1 hole of the extension bracket 7, disengaging from the 6-2 waist hole of the top plate 6. Only then can the cabinet door be opened. Meanwhile, the guide pin 10, under the pressure of the compression spring 8, moves towards the cabinet door, blocking the 7-1 hole of the extension bracket 7. When the door is open, the interlocking pin 4 is blocked by the guide pin 10, so the interlocking plate 12 cannot move down. Therefore, the closing operation cannot be performed when the door is open, which greatly improves the safety of the circuit breaker and the transformer substation combined interlocking.

[0019] Door closing procedure: See Figure 7 , Figure 8 If the transformer substation needs to be closed during operation, it must be done according to... Figure 3 Perform the operations in the order of 1, 2, 3, and 4 on panel 11. The initial position is visible. Figure 6 First, close cabinet door 1. Then, move limit pin 12-1 down to position 2, and simultaneously move interlock pin 4 down. At this point, interlock pin 4 will be inserted into the 6-2 waist hole of the top plate 6. Cabinet door 1 cannot be opened because it is blocked by interlock pin 4. However, if maintenance is required before power supply, limit pin 12-1 can be pushed up to position 1, at which point cabinet door 1 can be opened. When power supply begins, if the limit pin is in position 2, the grounding switch will be disconnected. At this point, the circuit breaker will be energized, and workers must not operate with the circuit breaker energized. Because of the circuit breaker's own interlocking mechanism, the interlocking plate cannot be pushed to position 1 of panel 11, and cabinet door 1 cannot be opened. This greatly improves safety, and there is no need to worry about workers accidentally performing maintenance while the circuit breaker is energized.

Claims

1. An interlocking device for a circuit breaker, wherein the circuit breaker is mounted on a frame inside a cabinet door, a panel is provided on the frame, a movable interlocking plate is provided on the rear side of the panel, and a limit pin is provided on the interlocking plate, the limit pin moving between several limited positions on the panel, characterized in that, The cabinet door has a top plate on its inner side, with a top plate hole at its end. The frame is fitted with a guide pin via an extension bracket, with a pin hole at the end of the extension bracket. A locking pin is provided on the locking plate. When the cabinet door is closed, the top plate pushes the guide pin inward, aligning the top plate hole with the pin hole. The limiting pin moves to the locking position, causing the locking pin to insert into the pin hole and the top plate hole, preventing the cabinet door from opening. When the limiting pin moves to the unlocking position, it causes the locking pin to be pulled out from the pin hole and the top plate hole. The guide pin pushes the top plate outward, causing the top plate hole and the pin hole to be misaligned, thus opening the cabinet door.

2. The interlocking device for the circuit breaker according to claim 1, characterized in that, A curved plate is installed on the cabinet door, and the curved plate is connected to the top plate.

3. The interlocking device for the circuit breaker according to claim 1, characterized in that, The interlocking plate is provided with an interlocking bent plate, and the end of the interlocking bent plate is provided with an interlocking pin.

4. The interlocking device for the circuit breaker according to claim 1, characterized in that, The extension bracket is a curved plate.

5. The interlocking device for the circuit breaker according to claim 4, characterized in that, The guide pin extends from the end of the bent plate.

6. The interlocking device for the circuit breaker according to claim 5, characterized in that, A compression spring is fitted onto the guide pin, with the rear end of the spring contacting the fixed pin and the front end contacting the stepped surface on the guide pin.

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