A large current test loop disconnector

Abstract

The utility model provides a kind of large current test loop isolating switch, belong to isolating switch technical field, including chassis, fixedly installed with static contact and conducting base on chassis, fixedly installed with watchband contact finger on static contact, it further includes conducting arm, one end of conducting arm is hinged with conducting base, the other end of conducting arm is detachably connected with static contact, hinge is connected with gas drive assembly on chassis, and arm body of conducting arm is hinged with gas drive assembly;Static contact is fixedly arranged at the middle position of mounting seat, and mounting seat is U-shaped structure, and a plurality of glass bead screws are fixedly arranged on the side wall of mounting seat two sides, and glass bead screw is pushed to the both sides of conducting arm, and the clamping force between watchband contact finger inserted into the end of conducting arm and conducting arm is increased. The both sides of conducting arm are pushed by the glass bead screws on the both sides of U-shaped mounting seat, effectively increase the clamping force between watchband contact finger and conducting arm, improve the reliability of contact, reduce the hidden trouble of unstable contact, local overheating and other caused by unstable contact.

Description

Technical Field

[0001] This utility model relates to the field of disconnecting switch technology, and in particular to a disconnecting switch for a high current test circuit. Background Technology

[0002] High-voltage disconnect switches are important switching devices in electrical systems. Their main function is to ensure the safety of high-voltage electrical appliances and equipment during maintenance and to isolate voltage. They cannot be used to cut off or connect load current or interrupt short-circuit current. They can only be used for certain switching operations that do not generate a strong electric arc and do not have an arc-extinguishing function.

[0003] Since various electrical equipment needs to be tested in the test station, the electrical circuit needs to carry dynamic and thermally stable currents under different operating conditions. In order to meet the test requirements, disconnecting switches for test circuits (such as publication number CN216353919U) have been developed. They adopt a strip contact finger structure, which improves the current carrying capacity and reduces the contact resistance. The strip contact fingers reduce the heat generated when the current passes through, thereby reducing energy loss and the risk of overheating.

[0004] Although the aforementioned test circuit disconnect switch reduces energy loss and overheating risk by using the watch-band contact fingers, the clamping force between the contact fingers and the conductive arm is small and fixed, resulting in poor contact stability and affecting its use. In addition, the conductive arm consists of two opposing contact plates with a gap between them that allows the contact fingers to be accommodated. This gap cannot accommodate large short-circuit currents (such as 250kA-300kA). When the disconnect switch is subjected to a large short-circuit current, the two contact plates attract each other. Since the ends of the two contact plates are in contact with the contact fingers, the gap in the middle of the two contact plates will be deformed by the electric attraction force of the contact plates. Utility Model Content

[0005] To address the technical problem in the existing test circuit disconnect switches described in the background art, where the clamping force between the contact fingers and the conductive arm is small and fixed, resulting in poor contact stability and affecting use, this utility model provides a disconnect switch for high-current test circuits.

[0006] The technical solution of this utility model is as follows: This utility model provides a disconnecting switch for a high-current test circuit, including a base frame, on which a stationary contact and a conductive base are fixedly mounted. A watchband contact finger is fixedly mounted on the stationary contact. It also includes a conductive arm, one end of which is hinged to the conductive base, and the other end of which is detachably connected to the stationary contact. A pneumatic drive assembly is hinged to the base frame and is hinged to the body of the conductive arm. The stationary contact is fixedly positioned in the middle of a U-shaped mounting base. Several ball screws are fixed on the side walls of the mounting base, pushing the conductive arm from both sides to increase the clamping force between the watchband contact finger inserted into the conductive arm and the conductive arm. By pushing the conductive arm from both sides of the U-shaped mounting base, the clamping force between the watchband contact finger and the conductive arm is effectively increased, improving the reliability of contact and reducing potential problems such as poor contact and localized overheating caused by unstable contact, thus ensuring the stable operation of the disconnecting switch under normal working conditions.

[0007] Preferably, the conductive arm includes two oppositely arranged contact plates, which are fixedly connected and have a gap. This not only preserves space to accommodate the watch strap fingers and meets the matching requirements of the conductive arm and the stationary contact, but also provides basic structural support for the contact plates through the fixed connection, preventing misalignment of the contact plates during assembly or normal use, and laying a structural foundation for improving the short-circuit high current withstand capability in the future.

[0008] Preferably, the ball screw includes a horizontally arranged mounting stud, which is threadedly connected to the mounting base. The end of the mounting stud closest to the stationary contact is open and hollow inside. A ball and a first spring are installed inside the mounting stud. The ball extends outward from the end of the mounting stud and abuts against the inner wall of the mounting stud via the first spring. When pushing the conductive arm, the first spring provides a continuous and buffered pushing force, preventing damage to the conductive arm from rigid pushing. At the same time, the rolling characteristics of the ball reduce the frictional resistance between the conductive arm and the ball screw, facilitating the docking or disengagement of the conductive arm with the stationary contact, improving the operational flexibility of the disconnecting switch, and the threaded connection of the mounting stud facilitates later maintenance and replacement, reducing maintenance costs.

[0009] Preferably, the end of the conductive arm that mates with the stationary contact is equipped with two sets of oppositely arranged connecting shafts. The distance between the two sets of connecting shafts is not less than the length of the stationary contact. This can limit the stationary contact on both sides when the conductive arm and the stationary contact are mated, preventing the conductive arm from shifting laterally during the mating process. This ensures that the watch strap fingers can be accurately inserted into the contact plate gap, improving the mating accuracy. At the same time, the connecting shafts can enhance the structural strength of the end of the conductive arm, reduce the risk of deformation of the end due to concentrated force, and further ensure the stability of the contact.

[0010] Preferably, the two contact plates are connected by a connecting shaft, with a sliding connection between the contact plates and the connecting shaft. Nuts are threaded onto both ends of the connecting shaft, and a second spring is fitted onto each end of the connecting shaft, positioned between the nut and the adjacent contact plate. The sliding connection between the contact plates and the connecting shaft, along with the second springs at both ends, forms an elastically adjustable contact plate spacing structure. The pushing force on the two contact plates can be adjusted by adjusting the compression of the second springs. The second springs can also help increase the clamping force between the contact plates and the watchband fingers, improving contact stability and ensuring reliable operation of the disconnecting switch under high current conditions. Simultaneously, the sliding connection allows the contact plates to move within a reasonable range, preventing deformation due to excessive stress caused by rigid fixing.

[0011] Preferably, a support plate is fixedly installed between the two contact plates. The support plate is located in the middle of the contact plates. The support plate in the middle of the contact plates can directly fill the empty area in the middle of the contact plates and provide rigid support for the middle part of the contact plates. When encountering a short circuit and a large current, the support plate can disperse the electric attraction force borne by the middle of the contact plates, prevent the contact plates from deforming inward and enhance the deformation resistance of the conductive arm.

[0012] Preferably, the stationary contact includes a copper busbar with an inverted T-shaped structure. Several watchband fingers are fixed on both sides of the copper busbar. The inverted T-shaped copper busbar structure allows the watchband fingers on both sides to be symmetrically distributed, ensuring that the fingers can evenly contact the contact plate when the conductive arm docks with the stationary contact, avoiding local current concentration caused by uneven distribution of the fingers. The copper busbar material has excellent conductivity, which can reduce resistance loss during current transmission. Combined with the structural advantages of the watchband fingers, energy loss and overheating risk are further reduced.

[0013] Preferably, a guide block is fixedly installed on one side of the copper busbar. The top of the guide block is a pointed tip, which is higher than the copper busbar. During the docking process between the conductive arm and the stationary contact, it can play a guiding and positioning role, so that the end of the conductive arm can quickly align with the mating position of the contact finger and the contact plate, reduce docking deviation, and improve operating efficiency. At the same time, the pointed tip structure can avoid jamming during docking and ensure the smooth operation of the disconnecting switch.

[0014] Preferably, the pneumatic drive assembly includes a cylinder, one end of which is hinged to the base frame, and the other end of which is hinged to a crank arm via a connector. The crank arm is rotatably mounted on the base via a main blade shaft, and the base is fixedly mounted on the base frame. The main blade shaft is hinged to the body of the conductive arm via a pull rod insulator. This provides a stable and controllable driving force for the rotation of the conductive arm. The pneumatic drive offers faster response and more uniform driving force, ensuring precise docking or separation of the conductive arm from the stationary contact. The pull rod insulator provides electrical insulation between the conductive arm and the drive components, preventing current conduction to the drive system and ensuring the safe operation of the drive assembly.

[0015] Preferably, the stationary contact and the conductive base are fixedly mounted on the base frame using post insulators. The post insulators have excellent insulation properties. Fixing the stationary contact and the conductive base to the base frame using post insulators can achieve electrical isolation between the stationary contact, the conductive base and the base frame, preventing current leakage to the base frame and causing safety hazards. At the same time, the post insulators can provide stable support force to ensure that the stationary contact and the conductive base are fixed in position during use, avoiding structural displacement caused by external vibration or force, and ensuring the stability of the overall structure of the disconnecting switch.

[0016] As can be seen from the above technical solutions, the advantages of this utility model are: 1. The ball screws on both sides of the U-shaped mounting base push the conductive arm to both sides, which effectively increases the clamping force between the strap contact finger and the conductive arm, improves the reliability of contact, reduces the hidden dangers of poor contact and local overheating caused by unstable contact, and ensures the stable use of the disconnecting switch under normal operating conditions.

[0017] 2. The conductive arm is equipped with a second spring on both sides. The compression of the second spring can be adjusted to adjust the pushing force on the two contact plates. The second spring can be used to increase the clamping force between the contact plates and the watch strap fingers, which improves the stability of the contacts and ensures the reliable operation of the disconnecting switch in high current environment.

[0018] 3. The ball screw contains a first spring and balls. When pushing the conductive arm, the first spring can provide a continuous and buffered pushing force to avoid damage to the conductive arm caused by rigid pushing. At the same time, the rolling characteristics of the balls can reduce the frictional resistance between the conductive arm and the ball screw, which facilitates the docking or separation of the conductive arm and the stationary contact, improves the operational flexibility of the disconnecting switch, and the threaded connection of the mounting stud facilitates later maintenance and replacement, reducing maintenance costs. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the main structure of the disconnecting switch for a high-current test circuit according to one or more embodiments of the present invention; Figure 2 This is a top view of the conductive part of the disconnecting switch for a high-current test circuit according to one or more embodiments of the present invention. Figure 3 This is a cross-sectional structural schematic diagram of a glass ball screw according to one or more embodiments of the present invention; Figure 4 This is a schematic diagram of the main structure of the watch strap finger according to one or more embodiments of the present invention; Figure 5 This is a side view structural diagram of the watch strap finger according to one or more embodiments of the present invention; The components represented by the various reference numerals in the diagram are: 1. Stationary contact; 2. Copper busbar; 3. Post insulator; 4. Tie rod insulator; 5. Cylinder; 6. Base; 7. Base frame; 8. Support plate; 9. Bead screw; 10. Connector; 11. Crank arm; 12. Main blade shaft; 13. Conductive arm; 14. Contact plate; 15. Conductive base; 16. Guide block; 17. Watch strap contact finger; 18. Mounting seat; 19. Mounting stud; 20. Ball bearing; 21. First spring; 22. Second spring; 23. Connecting shaft; 24. Nut. Detailed Implementation

[0021] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0022] Example 1 In a typical embodiment of this utility model, such as Figures 1-5As shown, a disconnecting switch for a high-current test circuit is proposed, comprising: a stationary contact 1, a post insulator 3, a pneumatic drive assembly, a base frame 7, glass ball screws 9, a conductive arm 13, contact plates 14, a conductive base 15, and a mounting base 18. The stationary contact 1 and the conductive base 15 are respectively fixedly mounted on the base frame 7 via the post insulator 3, which is vertically arranged. The stationary contact 1 and the conductive base 15 are arranged opposite each other. One end of the conductive arm 13 is hinged to the conductive base 15, and the other end of the conductive arm 13 is used to cooperate with the stationary contact 1. The conductive arm 13 includes two oppositely arranged contact plates 14, which are fixedly connected and have a gap to form the conductive arm 13. The pneumatic drive assembly... One end of the component is hinged to the base frame 7, and the other end is hinged to the body of the conductive arm 13. Thus, the conductive arm 13 is driven to swing by air, so that one end of the conductive arm 13 contacts or separates from the stationary contact 1. The stationary contact 1 is fixedly mounted on the top of the corresponding support insulator 3 by the mounting base 18. The mounting base 18 is a U-shaped structure with an open top. The stationary contact 1 is fixedly mounted in the middle position of the mounting base 18. Several glass ball screws 9 are fixed on the side walls on both sides of the mounting base 18, so as to use the glass ball screws 9 to provide a pushing reaction force on the two contact plates 14 of the conductive arm 13, thereby increasing the clamping force between the two contact plates 14 and the contact fingers 17 on the surface of the stationary contact 1 inserted between the two contact plates 14.

[0023] Specifically, such as Figure 1 As shown, the conductive base 15 is fixedly connected to the base frame 7 via the base 6. The pneumatic drive assembly includes a pull rod insulator 4, a cylinder 5, a connector 10, a crank arm 11, and a main blade shaft 12. One end of the cylinder 5 is hinged to the base frame 7, and the other end (i.e., the telescopic end) of the cylinder 5 is threadedly connected to the connector 10. The connector 10 is hinged to the crank arm 11. The crank arm 11 is rotatably mounted on the base 6 via the main blade shaft 12. The main blade shaft 12 is connected to the base of the pull rod insulator 4 via a connecting rod. The top of the pull rod insulator 4 is hinged to the body of the conductive arm 13. The crank arm 11, the main blade shaft 12, the connecting rod, and the pull rod insulator 4 are combined to form a connecting rod structure. By extending and retracting the piston shaft of the cylinder 5, the crank arm 11 can be rotated. The rotation of the crank arm 11 can cause the main blade shaft 12 to rotate, thereby using the connecting rod to realize the lifting and lowering of the pull rod insulator 4. Under the pushing and pulling action of the pull rod insulator 4, the conductive arm 13 can perform opening and closing actions on the stationary contact 1.

[0024] The stationary contact 1 includes a copper busbar 2 and watch strap contact fingers 17. The copper busbar 2 has an inverted T-shaped structure and is fixedly installed in the middle position of the mounting base 18 by bolts. Several watch strap contact fingers 17 are fixed on both sides of the copper busbar 2, such as... Figure 4 and Figure 5As shown, the specific number of mounting pieces for the watch band contact 17 is determined according to different dynamic and thermal stability parameters. By using the watch band contact 17 to replace the transmission contact, the meshing between the stationary contact 1 and the contact plate 14 is increased, which can effectively reduce the contact resistance. The watch band contact 17 reduces the heat generated when current passes through, thereby reducing energy loss and the risk of overheating.

[0025] The watchband contact 17 is an existing structure. It is made of an elastic metal sheet (usually copper or copper alloy) and silver-plated to improve conductivity. Its shape consists of multiple parallel elastic contact pieces forming a watchband-like structure. It maintains stable contact with the moving contact through mechanical pressure. The contact method adopts multi-point parallel contact to break the surface oxide layer and ensure effective conductive area. The installation method is usually embedded in the slot of the copper busbar 2 and fixed by riveting or screws. The elastic design of the contact finger provides constant contact pressure, reduces contact resistance and suppresses heat generation. It crushes the surface contamination layer (such as oxide film and oil) through multi-point contact to maintain a stable electrical connection. During opening and closing operations, the contact finger adapts to the sliding of the moving contact through elastic deformation, reducing wear.

[0026] Several ball screws 9 are provided on both sides of the stationary contact 1. The ball screws 9 are fixedly installed on the mounting base 18 for pushing against the side of the contact plate 14. The ball screws 9 are arranged horizontally, such as... Figure 2 As shown, several glass bead screws 9 on the same side are spaced apart along the length of the conductive arm 13, such as... Figure 3 As shown, the glass ball screw 9 includes a mounting stud 19, a ball 20, and a first spring 21. The mounting stud 19 has external threads, and a threaded hole is opened at the corresponding position of the mounting base 18. The mounting stud 19 is fixedly connected to the mounting base 18 by a threaded connection. The end of the mounting stud 19 near the stationary contact 1 is open and hollow inside, and the ball 20 and the first spring 21 are installed inside. The ball 20 is a glass ball structure. Part of the ball 20 extends outward from the end of the mounting stud 19 for rolling contact with the outer wall of the contact plate 14. The ball 20 abuts against the inner wall of the mounting stud 19 through the first spring 21. The first spring 21 not only ensures effective contact between the ball 20 and the contact plate 14, but also plays a buffering role when closing the circuit, avoiding rigid collision between the contact plate 14 and the ball 20, and protecting the contact plate 14.

[0027] In practical use, the axial position of the mounting stud 19 can be changed to change the jacking force and meet different test requirements.

[0028] like Figure 2As shown, the end of the conductive arm 13 that mates with the stationary contact 1 is also equipped with a connecting shaft 23, a second spring 22, and a nut 24. The connecting shaft 23 has two sets for connecting the two contact plates 14. The two sets of connecting shafts 23 are arranged opposite to each other, each set containing several connecting shafts 23. The connecting shafts 23 in the same set are spaced apart in opposite directions along the width of the contact plate 14. The distance between the two sets of connecting shafts 23 is not less than the length of the stationary contact 1. The two sets of connecting shafts 23 are used to connect the stationary contact 1 and the conductive arm 13. The connecting shaft 23 includes a smooth shaft section and a threaded section. The threaded section is fixedly arranged at both ends of the smooth shaft section, and the threaded section and the smooth shaft section are coaxially arranged. The optical shaft section of the connecting shaft 23 is used for sliding connection with the two contact plates 14, and the threaded section is used for threaded connection with the nut 24. Two second springs 22 are sleeved on each connecting shaft 23. The second springs 22 are sleeved on the threaded section and located between the contact plate 14 and the adjacent nut 24. A washer is provided between the second spring 22 and the contact plate 14. The compression of the second spring 22 can be adjusted by adjusting the position of the nut 24, thereby adjusting the pushing force on the two contact plates 14. The second spring 22 can be used to help increase the clamping force between the contact plate 14 and the watch strap contact finger 17, which improves the stability of the contact and ensures the reliable operation of the disconnecting switch in a high current environment.

[0029] A guide block 16 is also fixedly installed on one side of the copper busbar 2 along its length. The top of the guide block 16 is a pointed tip, and the top of the guide block 16 is higher than the top of the copper busbar 2 to serve as a guide. The copper busbar 2 is inserted between the two contact plates 14 of the conductive arm 13.

[0030] like Figure 2 As shown, a support plate 8 is also fixedly installed between the two contact plates 14 of the conductive arm 13. The support plate 8 is fixedly installed between the two contact plates 14 by bolts, and the support plate 8 is located in the middle position of the contact plates 14. The support plate 8 is an insulating glass cloth plate, which is used to support the easily deformable middle part of the two contact plates 14. When current flows through the two parallel contact plates 14 in the same direction, the two contact plates 14 generate an electromotive force that attracts each other, which increases the contact pressure and improves the operational reliability. The support plate 8 is installed in the middle of the two contact plates 14 to provide support for the contact plates 14 and prevent the contact plates 14 from attracting each other and deforming.

[0031] It should be noted that the support plate 8 and the contact plate 14 are connected by a connecting shaft 23, and a nut 24 is also connected to the connecting shaft 23. The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A disconnecting switch for a high-current test circuit, comprising: The base frame (7) is fixedly mounted with a stationary contact (1) and a conductive base (15). The stationary contact (1) is fixedly mounted with a watch strap finger (17) and also includes a conductive arm (13). One end of the conductive arm (13) is hinged to the conductive base (15), and the other end of the conductive arm (13) is detachably connected to the stationary contact (1). A pneumatic drive assembly is hinged on the base frame (7) and is hinged to the body of the conductive arm (13). The stationary contact (1) is fixedly positioned in the middle of the mounting base (18). The mounting base (18) is a U-shaped structure. Several glass ball screws (9) are fixedly provided on the side walls on both sides of the mounting base (18). The glass ball screws (9) push the two sides of the conductive arm (13) to increase the clamping force between the watch strap finger (17) inserted into the end of the conductive arm (13) and the conductive arm (13).

2. The isolating switch for a high-current test circuit according to claim 1, characterized in that, The conductive arm (13) includes two oppositely arranged contact plates (14), which are fixedly connected and have a gap between them.

3. The isolating switch for a high-current test circuit according to claim 1, characterized in that, The ball screw (9) includes a horizontally arranged mounting stud (19), which is threadedly connected to the mounting base (18). The mounting stud (19) is open at one end near the stationary contact (1) and is hollow inside. A ball (20) and a first spring (21) are installed inside the mounting stud (19). The ball (20) extends outward from the end of the mounting stud (19), and the ball (20) abuts against the inner wall of the mounting stud (19) through the first spring (21).

4. The isolating switch for a high-current test circuit according to claim 2, characterized in that, Two sets of oppositely arranged connecting shafts (23) are installed at one end of the conductive arm (13) that mates with the stationary contact (1), and the distance between the two sets of connecting shafts (23) is not less than the length of the stationary contact (1).

5. The disconnecting switch for a high-current test circuit according to claim 4, characterized in that, The two touch plates (14) are connected by a connecting shaft (23). The touch plates (14) and the connecting shaft (23) are slidably connected. Nuts (24) are threaded to both ends of the connecting shaft (23), and a second spring (22) is sleeved on both ends of the connecting shaft (23). The second spring (22) is located between the nut (24) and the adjacent touch plate (14).

6. The isolating switch for a high-current test circuit according to claim 2, characterized in that, A support plate (8) is fixedly installed between the two touch plates (14), and the support plate (8) is located in the middle of the touch plates (14).

7. The disconnecting switch for a high-current test circuit according to claim 1, characterized in that, The stationary contact (1) includes a copper busbar (2), which is an inverted T-shaped structure. Several watch strap fingers (17) are fixed on both sides of the copper busbar (2).

8. The disconnecting switch for a high-current test circuit according to claim 7, characterized in that, A guide block (16) is fixedly installed on one side of the copper busbar (2). The top of the guide block (16) is a pointed tip, and the top of the guide block (16) is higher than the copper busbar (2).

9. The disconnecting switch for a high-current test circuit according to claim 1, characterized in that, The pneumatic drive assembly includes a cylinder (5), one end of which is hinged to the base frame (7), and the other end of which is hinged to the crank arm (11) via a connector (10). The crank arm (11) is rotatably mounted on the base (6) via the main blade shaft (12). The base (6) is fixedly mounted on the base frame (7). The main blade shaft (12) is hinged to the body of the conductive arm (13) via a pull rod insulator (4).

10. The disconnecting switch for a high-current test circuit according to claim 1, characterized in that, The stationary contact (1) and the conductive base (15) are fixedly mounted on the base frame (7) by the post insulator (3).

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