Direct-current quick circuit breaker

Abstract

The invention discloses a direct-current quick circuit breaker which comprises a frame, an operating mechanism, a contact system, a tripping device and a buffer assembly, the operating mechanism, the contact system, the tripping device and the buffer assembly are arranged on the frame, the direct-current quick circuit breaker further comprises an arc extinguishing device and a magnetic blow-out device, the arc extinguishing device and the magnetic blow-out device are arranged above the contact system and used for connecting and breaking current in a first main loop and a second main loop, and the operating mechanism comprises a shifting fork assembly. The arc extinguishing device is connected with an arc striking angle of the contact system through a pawl, the contact system adopts a double-gear contact design, and a spring or / and a disc spring used for providing closing force between the moving arc contact and the static arc contact is arranged between the moving arc contact and the arc contact supporting shaft; during closing, the arc contact is firstly contacted through sequential control, on one hand, the energy of the main contact in the closing process can be absorbed to reduce bounce, and on the other hand, the bounce time can be greatly shortened and even bounce can be eliminated by utilizing the time difference of the contact moments of the arc contact and the main contact.

Description

Technical Field

[0001] The present invention belongs to the technical field of DC switching electrical appliances, and in particular relates to a DC fast circuit breaker. Background Art

[0002] As the capacity of urban rail transit DC traction power supply systems continues to increase, the requirements for the breaking performance of DC fast circuit breakers used to cut off short-circuit fault currents are also constantly increasing.

[0003] For the air-type DC fast circuit breakers widely used in urban rail transit DC traction power supply systems, the existing products adopt a single-stage contact design. When the circuit breaker is disconnected, the fault arc is directly generated at the main contact. When the disconnecting current is large, the contacts are very likely to be severely burned or even adhered, which in turn affects the life of the circuit breaker and restricts the improvement of the circuit breaker's breaking performance.

[0004] Contact bounce is a major cause of severe erosion and even adhesion during the disconnection of DC fast circuit breakers. Existing products often reduce contact bounce by reducing contact pressure or using buffers. However, these methods can only limit contact bounce to a certain range and are no longer applicable. Otherwise, other important performance indicators such as the circuit breaker's disconnection speed will be affected. Contact bounce has now become a key factor restricting further improvement in the disconnecting capacity of DC fast circuit breakers. Summary of the Invention

[0005] In response to the above deficiencies in the prior art, the present invention provides a DC fast circuit breaker with an improved contact system design, which can reduce or even completely eliminate the circuit breaker closing bounce and improve the circuit breaker breaking performance.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a DC fast circuit breaker, including a frame and an operating mechanism, a contact system, a tripping device and a buffer assembly arranged on the frame, and also including an arc extinguishing device and a magnetic blowing device arranged above the contact system, for connecting and disconnecting current in the main circuit 1 and the main circuit 2; the operating mechanism includes a fork assembly; the arc extinguishing device is connected to the arc ignition angle of the contact system through a pawl; the contact system includes a moving main contact overlapped with the fork assembly and a static main contact adapted to the moving main contact, the moving main contact The main contact is connected to the moving arc contact through a soft connection. The moving main contact contacts the top of the buffer assembly. An arc contact bracket is provided on the moving main contact. The bottom of the arc contact bracket is connected to the arc contact support shaft. The front of the moving arc contact is connected to the arc contact bracket using a rotating shaft and can rotate around the rotating shaft. A static arc contact is provided on the static main contact. The arc striking angle includes a static arc striking angle welded on the static arc contact and a moving arc striking angle set on the moving arc contact. A spring or / and disc spring for providing closing force between the moving arc contact and the static arc contact is provided between the moving arc contact and the arc contact support shaft.

[0007] The DC fast circuit breaker has a frame comprising a main frame and a cover plate. The contact system, tripping device, and buffer assembly are arranged inside the main frame. The arc extinguishing device is arranged on the cover plate. The magnetic blowout device is arranged below the cover plate and is insulated from the contact system by the main frame. The operating mechanism and the buffer assembly are arranged on the same side of the main frame. The contact system is connected to the magnetic blowout device via a mounting base to form a magnetic / electric circuit.

[0008] The contact system of the DC fast circuit breaker further includes a static main contact copper bar and a lower copper bar arranged and mounted on the main frame, and a heat transfer assembly connected to the iron core via a longitudinal connecting bar. The trip device is installed around the lower copper bar, and the top actuating component overlaps the fork assembly to achieve overcurrent tripping.

[0009] The DC fast circuit breaker further includes an auxiliary switch box assembly arranged and mounted on the main frame. The auxiliary switch box assembly includes components such as an opening and closing indicator, an aviation plug, and a micro switch. The auxiliary switch box assembly is located below the operating mechanism on the same side as the operating mechanism and contacts the buffer assembly.

[0010] A DC fast circuit breaker, the magnetic blowing device of which includes a base and iron cores symmetrically arranged and mounted on both sides of the base and magnetically connected to the moving arcing angle through transverse connecting bars, the iron cores being connected to magnetic conductive plates located on both sides of the static arc contact and the moving arc contact, magnetic blowing coils being wound around the iron cores, the tails of the coils on both sides being magnetically connected through transverse connecting bars, the iron cores on both sides being connected by a base made of magnetic conductive material, the base and the transverse connecting bars being separated by an insulating partition, the coil heads on both sides being extended by lead wires to the outside of the bottom of the iron core and connected to the longitudinal connecting bars, the other side of the longitudinal connecting bars being connected to the heat transfer assembly.

[0011] The operating mechanism of the DC fast circuit breaker further includes an electromagnet assembly and a wear indicator assembly. The wear indicator assembly is arranged at the tail of the electromagnet assembly, and the shift fork assembly is arranged at the head of the electromagnet assembly and overlaps with the contact system.

[0012] The arc extinguishing device of the DC fast circuit breaker includes a pad arranged on the cover plate and an arc extinguishing chamber located on the pad. The bottom of the arc extinguishing chamber has a V-shaped opening. The interior of the arc extinguishing chamber has arc extinguishing grids arranged in a staggered manner and an insulating grid placed closely above the arc extinguishing grids.

[0013] A DC fast circuit breaker is described, in which an insulating block is arranged near the main frame and the moving arc contact to prevent arc splashing during the disconnection process and does not interfere with the movement of the moving arc contact. The moving arc striking angle and the static arc striking angle are wrapped with a ferromagnetic shell to enhance the magnetic field driving the arc movement. The magnetic conductive plate is arranged at the connection between the moving arc contact, the static arc contact and the moving arc striking angle and the static arc striking angle. The bottom end of the magnetic conductive plate is lower than the point / line contact part of the moving arc contact and the static arc contact. The top end of the magnetic conductive plate is closely attached to the cover plate, and the outer side is connected to the top of the iron core. The front end of the moving arc contact is inserted into the tail end of the arc contact bracket, which is clamped into the clamping piece and then inserted into the arc contact support shaft together.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The DC fast circuit breaker provided by the present invention has a long service life, a fast breaking speed, a small contact bounce, a strong maintainability, a low contact resistance, and a strong anti-welding performance. By adding a moving arc contact and a static arc contact and timing control, the arc originally generated at the contact point between the moving main contact and the moving arc contact during the circuit breaker breaking process is transferred to the contact point between the moving arc contact and the static arc contact, thereby reducing the ablation of the circuit breaker main contacts and improving the service life of the circuit breaker.

[0016] The moving arc contact and the static arc contact provided by the present invention can be directly replaced without disassembling components such as the main frame, and have strong maintainability.

[0017] The contact system provided by the present invention adopts a dual-speed contact design. When closing the circuit, the arc contact is made to contact first through timing control. On the one hand, it can absorb the energy of the main contact during the closing process to reduce bounce. On the other hand, the time difference between the contact moments of the arc contact and the main contact can be used to greatly reduce the bounce time or even eliminate bounce.

[0018] The arc starting of the DC fast circuit breaker provided by the present invention is located in the arc contact area. When opening the circuit, the main contact can drive the arc contact to separate, and the contact part of the arc contact and the contact part of the main contact can be regarded as a parallel circuit in the electrical circuit, which reduces the contact resistance and reduces the heat generation in the contact area. Therefore, the contact system is not prone to adhesion when performing short-circuit breaking or load opening, and has strong anti-welding performance.

[0019] The surfaces of the dynamic arc-strike angle and the static arc-strike angle provided by the present invention are wrapped with a ferromagnetic shell, which can enhance the magnetic field strength in the arc movement area during the breaking process, and drive the arc to transfer to the arc extinguishing chamber of the arc extinguishing device more quickly. At the same time, since the contact bounce is greatly reduced by increasing the arc contact, the compression amount of the overtravel spring can be appropriately increased to increase the opening speed of the circuit breaker. The above two points are both conducive to improving the breaking speed of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the contact system of the present invention;

[0022] Figure 3 yes Figure 2 A partial enlarged view of

[0023] Figure 4 It is a structural schematic diagram of the moving contact assembly of the present invention;

[0024] Figure 5 This is a schematic structural diagram of the dynamic arc striking angle of the present invention;

[0025] Figure 6 It is a structural schematic diagram of the static arc striking angle of the present invention.

[0026] The figures are marked as follows: 1—static main contact copper bar, 2—lower copper bar, 3—main frame, 4—operating mechanism, 5—arc extinguishing device, 6—magnetic blowing device, 7—contact system, 8—moving main contact, 9—static main contact, 10—moving arc contact, 11—static arc contact, 12—arc contact bracket, 13—rotating shaft, 14—flexible connection, 15—moving arc striking angle, 15-1—arc angle support, 15-2—end block, 15-3—middle rod, 15-4—tail plate, 15-5—outer magnetic conductive shell, 15-6—insulating partition, 16—static arc striking angle, 16-1— Bending rod, 16-2—tail plate, 16-3—outer magnetic conductive shell, 17—arcing contact support shaft, 18—mounting base, 19—tripping device, 20—buffer assembly, 21—auxiliary switch box assembly, 22—shift fork assembly, 23—magnetic conductive plate, 24—magnetic blow coil, 25—iron core, 26—base, 27—insulating partition, 28—transverse connecting row, 29—longitudinal connecting row, 30—heat transfer assembly, 31—overtravel spring, 32—disc spring assembly, 33—gasket, 34—cover plate, 35—clamping plate, 36—anti-loosening gasket, 37—hexagonal shaft. DETAILED DESCRIPTION

[0027] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0028] like Figure 1 and Figure 2 As shown, this embodiment provides a DC fast circuit breaker with high breaking performance that is not only suitable for use in rail transit DC traction power supply systems, including a frame consisting of a main frame 3 and a cover plate 34, an operating mechanism 4, an arc extinguishing device 5, a magnetic blowout device 6, a contact system 7, a tripping device 19, a buffer assembly 20, an auxiliary switch box assembly 21, etc.

[0029] The operating mechanism 4 is arranged and installed on one side of the main frame 3, and includes an electromagnet assembly, a fork assembly 22 and a wear indicator assembly; the wear indicator assembly is arranged at the tail of the electromagnet assembly, and the fork assembly 22 is arranged at the head of the electromagnet assembly and overlaps with the moving main contact 8 of the contact system 7.

[0030] The arc extinguishing device 5 is arranged and installed on the cover plate 34 on the top of the main frame 3, and is connected to the arc striking angle of the contact system 7 through a pawl; the arc extinguishing device 5 includes an arc extinguishing chamber and a pad, wherein the bottom of the arc extinguishing chamber is V-shaped, the internal arc extinguishing grids are arranged in a staggered manner, and the insulating grids are placed closely above the arc extinguishing grids. The pad is placed between the bottom of the arc extinguishing chamber and the cover plate 34, and its connecting surface has the same slope as the V-shaped closing of the bottom of the arc extinguishing chamber.

[0031] The magnetic blowing device 6 comprises a base 26 and iron cores 25 symmetrically mounted on either side of the base 26. The two iron cores 25 are connected by the base 26 made of a magnetically conductive material. The iron cores 25 are magnetically connected to the moving arc horn 15 via transverse connecting bars 28. Magnetic conductive plates 23 located on either side of the static arc contact 11 and the moving arc contact 10 are connected to the iron core 25. A magnetic blowing coil 24 is wound around the iron core 25. The base 26 and the transverse connecting bars 28 are separated by insulating partitions 27. The tails of the coils 24 on either side of the magnetic blowing device 6 are connected by the transverse connecting bars 28. The iron core 25 is connected to the heat transfer assembly 30 via longitudinal connecting bars 29 to form a closed magnetic circuit.

[0032] The contact system 7 is arranged and installed inside the main frame 3, and the tripping device 19 is arranged and installed inside the main frame 3, surrounding the lower copper bar 2 of the contact system 7. The contact system 7 adopts a double-stage contact design, and the main body includes a moving main contact 8, a static main contact 9, a moving arc contact 10, a static arc contact 11, a moving arc striking angle 15, a static arc striking angle 16 and other components, wherein the moving arc contact 10 is installed on the moving main contact 8 through an arc contact bracket 12 and a rotating shaft 13. In order to ensure the direction of arc movement and the life of the circuit breaker during the breaking process, the arc contact bracket 12 and the rotating shaft 13 are made of high-strength and non-magnetic materials. The arc contact support shaft 17 is riveted to the arc contact bracket 12. The top of the arc contact bracket 12 has a mounting hole that can cooperate with the rotating shaft 13, and the bottom is provided with a mounting platform for riveting the arc contact support shaft 17. The arc contact support shaft 17 and the arc contact bracket 1 2. The bottom mounting platform is riveted using a method including but not limited to clearance fit to ensure that there is a certain amount of movement after the arc contact support shaft 17 is fixed to avoid excessive internal stress affecting the service life. A force-applying device including but not limited to a spring or a disc spring or a combination of the two is arranged along the arc contact support shaft 17 between the tail of the moving arc contact 10 and the bottom mounting platform of the arc contact support shaft 17 to provide a closing force between the moving arc contact 10 and the static arc contact 11. By adjusting the position of the moving arc contact 10 and the force-applying device, the contact resistance, main arc timing, and closing bounce between the moving arc contact 10 and the static arc contact 11 when the circuit breaker is closed can meet the design requirements of the circuit breaker, and the main arc timing when the circuit breaker is opened can meet the design requirements of the circuit breaker.

[0033] The moving arc contact 10 is mounted on the moving main contact 8 and electrically connected to the moving main contact 8 via a flexible connector 14. The static arc contact 11 is mounted on the static main contact 9 using screws. The moving arc striking angle 15 is mounted on the back of the moving arc contact 10 and electrically connected to the magnetic blowing device 6 via a mounting base. The design dimensions of the moving arc striking angle 15 ensure a smooth transition between its front end and the front end of the moving arc contact 10 after installation, ensuring that the arc can smoothly jump to the moving arc striking angle 15 and the static arc striking angle 16 during the disconnection process. The static arc striking angle 16 is directly welded to the static arc contact 11. The moving arc contact 10 is fixed to the flexible connector 14 using screws and is provided with a screw locking feature. The design dimensions of the moving arc contact 10 ensure that when it rotates around the rotating shaft 13 within a certain range, a certain distance between the moving main contact 8 and the static main contact 9 is maintained when the moving arc contact 10 contacts the static arc contact 11 during the closing process. Through timing control, the moving arc contact 10 and the static arc contact 11 are in contact first during the closing process, and the moving main contact 8 and the static main contact 9 are in contact later. During the opening process, the moving main contact 8 and the static main contact 9 are separated first, and the moving arc contact 10 and the static arc contact 11 are separated later. This ensures that the arc is always generated at the contact point of the moving arc contact 10 and the static arc contact 11 during the breaking process of the circuit breaker, reduces the erosion of the moving main contact 8 and the static main contact 9, improves the electrical life and breaking performance of the circuit breaker, and reduces closing bounce. At the same time, since the moving arc contact 10 and the static arc contact 11 are easier to replace than the moving main contact 8 and the static main contact 9, the maintenance cost of the circuit breaker is reduced.

[0034] The contact system 7 also includes a static main contact copper bar 1 and a lower copper bar 2 arranged and mounted on the main frame 3, and a heat transfer component 30 connected to the iron core 25 via a longitudinal connecting bar 29. A support column is arranged between the static main contact copper bar 1 and the lower copper bar 2. The heat transfer component 30 is symmetrically arranged and mounted on both sides of the moving main contact 8 and directly connected to the lower copper bar 2. The moving main contact 8 is arranged and mounted in the middle of the front end slot of the lower copper bar 2 via a rotating shaft 13. The trip device 19 is installed around the lower copper bar 2, and the top actuating component overlaps with the fork assembly 22 to achieve overcurrent tripping. The static arc contact 11 is arranged and mounted on the static main contact copper bar 1.

[0035] The buffer assembly 20 is arranged and installed on the inner side of the main frame 3, below the operating mechanism 4, and its top end is overlapped with the moving main contact 8 of the contact system 7 to absorb the closing energy of the moving main contact 8.

[0036] The auxiliary switch box assembly 21 is arranged and installed on the same side of the main frame 3 and the operating mechanism 4 and is connected to the buffer assembly 20, including but not limited to components such as an opening and closing indicator, an aviation plug, and a micro switch.

[0037] When the DC fast circuit breaker of this embodiment is closed, the fork assembly 22 of the operating mechanism 4 pushes the moving main contact 8 to perform a snap-on axial movement. When the moving main contact 8 moves to a position close to the closing position 1, the moving main contact 8 contacts the buffer assembly 20. When the moving main contact 8 moves to a position close to the closing position 2, the moving arc contact 10 first contacts the static arc contact 11, and then the moving main contact 8 contacts the static main contact 9. When the circuit breaker is short-circuited and opened, when the short-circuit current exceeds the setting value of the trip device 19, the electric force generated by the short-circuit current drives the trip device 19 to push the fork assembly 22 to open the circuit breaker. During the opening process, the moving main contact 8 and the static main contact 9 are first separated, and the short-circuit current is transferred to the moving arc contact 10. The static arc contact 11 is connected in a circuit, and then the moving arc contact 10 is separated from the static arc contact 11 to generate an arc. The arc is affected by the magnetic field force provided by the magnetic field generated by the magnetic blowing device 6 and moves toward the arc extinguishing device 5, and jumps to the moving arc striking angle 15 and the static arc striking angle 16. Under the action of the magnetic field force provided by the magnetic field generated by the ferromagnetic shell of the arc striking angle, the arc is further accelerated to move to the arc extinguishing device, and finally the arc is extinguished and disconnected. When the circuit breaker is performing a short circuit disconnection, an arc is generated at the moving arc contact 10 and the static arc contact 11 of the arc contact, which reduces the loss of the moving main contact 8 and the static main contact 9, and helps to improve the service life of the circuit breaker. At the same time, since the moving arc striking angle 15 and the static arc striking angle 16 have ferromagnetic shells, they help the rapid movement of the arc, thereby improving the disconnection speed of the circuit breaker.

[0038] Detailed implementation methods such as Figure 2 、 Figure 3 and Figure 4As shown, the contact system 7 is connected to the magnetic blowing device 6 via the arc striking angle mounting base 18 to form a magnetic circuit / electrical circuit. The magnetic blowing device 6 includes a base 26 and an iron core 25 symmetrically mounted on both sides of the base 26 and magnetically connected via a transverse connecting row 28. The iron core 25 is connected to a magnetic conductive plate 23 located on both sides of the static arc contact 11 and the moving arc contact 10. The magnetic conductive plates 23 are arranged at the junction of the moving arc contact 10, the static arc contact 11 and the moving arc striking angle 15, and the static arc striking angle 16. The bottom end of the magnetic conductive plate 23 is lower than the point / line contact portion of the moving arc contact 10 and the static arc striking angle 11. The top end of the magnetic conductive plate 23 is in close contact with the cover plate 34, and the outer side is connected to the top of the iron core 25, forming a closed magnetic circuit 1: magnetic conductive plate 23 - air - iron core 25 - base 26. Magnetic blow-off coils 24 are wound around the iron core 25 and magnetically connected via transverse connecting bars 28. Lead wires extend from the ends of the coils 24 on both sides to the outside of the bottom of the iron core 25, where they connect to longitudinal connecting bars 29. The other side of longitudinal connecting bars 29 is connected to a heat transfer assembly 30, forming a closed electrical circuit: static main contact copper bar 1 - static arc-starting angle 16 - arc-moving arc-starting angle 15 - mounting base 18 - transverse connecting bars 28 - coils 24 - heat transfer assembly 30 - lower copper bar 2. In this embodiment, the main body of the magnetic blow-off device 6 utilizes a self-excited coil, but this is by no means a limitation. Permanent magnets or separately excited coils can be used to modify the magnetic blow-off device according to specific operating conditions.

[0039] like Figure 4As shown, an arc contact bracket 12 is welded on the moving main contact 8. In addition to welding, the arc contact bracket 12 and the moving main contact 8 are fixed with redundant fixing methods including but not limited to rivets. The top of the arc contact bracket 12 has a mounting hole that can cooperate with the rotating shaft 13, and the bottom has a mounting platform that can be riveted with the arc contact support shaft 17: after the arc contact support shaft 17 is riveted and fixed, the overtravel spring 31 is arranged along the arc contact support shaft 17; the front end of the moving arc contact 10 is inserted into the arc contact bracket 12, the tail end is clamped into the clamping piece 35, and then inserted into the arc contact support shaft 17 together, the rotating shaft 13 is inserted, and fixed with but not limited to a cotter pin; the disc spring group 32 and the gasket 33 are placed on the hexagonal shaft 37 in sequence and screwed into the arc contact support shaft 17; the soft connection 14 is placed at the corresponding position on the middle surface of the clamping piece 35 The movable contact assembly is installed on the lower copper bus 2 after the assembly is completed, and the two ends are fixed on the movable main contact 8. The middle part is padded with an anti-loosening gasket 36 and then tightened. The movable contact assembly obtained after the assembly is completed is installed as a whole on the lower copper bus 2. The movable contact assembly is pushed until the movable arc contact 10 contacts the static arc contact 11, and the distance X between the movable main contact 8 and the static main contact 9 is measured. The static position of the movable arc contact 10 can be adjusted by adjusting the screw-in length of the hexagonal shaft 37 to adjust the X value to an appropriate size. In this embodiment, the contact pressure between the movable arc contact 10 and the static arc contact 11 when the DC fast circuit breaker is in the closed position can be adjusted by adjusting the overtravel spring 31 and the disc spring group 32, but this method is by no means a limitation. In addition, in this embodiment, the soft connection 14 is made of a soft copper braid bent, but it is by no means a limitation. Two copper braids or other methods can also be used to achieve electrical connection between the movable arc contact 10 and the movable main contact 8.

[0040] like Figure 5 As shown, the moving arc horn 15 in this embodiment is composed of an arc horn support 15-1, an end block 15-2, a middle rod 15-3, a tail plate 15-4, an outer magnetic conductive shell 15-5, and an insulating partition 15-6. The arc horn support 15-1 is used for installation with the mounting base 18; the end block 15-2 is in the shape of an arc trapezoid, wider at the bottom and narrower at the top, with a surface curvature close to the top of the moving arc contact 10 to facilitate arc transfer and jumping; the front end surface of the middle rod 15-3 has the same curvature as the end block 15-2, with a smooth transition; the tail plate 15-4 is arranged horizontally to facilitate crimping and fixing with the arc horn inside the arc extinguishing chamber to form an equipotential body; the outer magnetic conductive shell 15-5 is closely attached to the surface of the end block 15-2 and the middle rod 15-3 and is riveted to the surface; the insulating partition 15-6 is used to isolate the outer magnetic conductive shell 15-5 from arc erosion and is installed in the slot at the bottom of the end block 15-2.

[0041] like Figure 6As shown, in this embodiment, the static arc-striking angle 16 is composed of a bent rod 16-1, a tail plate 16-2, and an outer magnetic conductive shell 16-3, and is welded to the static arc-striking contact 11. In this embodiment, the dynamic arc-striking angle 15 and the static arc-striking angle 16 are welded together from multiple parts, but this is by no means a limitation; they can also be processed as a whole. The outer magnetic conductive shell 15-5 and the outer magnetic conductive shell 16-3 are fixed by stamping and riveting, but this is by no means a limitation; other methods such as welding can also be used for fixing. The insulating partition 15-6 can be processed separately, but this is by no means a limitation; a reserved barrier position can also be used on the main frame 3 or other parts.

[0042] The above examples are merely illustrative of the present invention and do not limit the scope of protection of the present invention. Any design that is identical or similar to the present invention falls within the scope of protection of the present invention.

Claims

1. A DC fast circuit breaker, characterized in that: The invention comprises a frame and an operating mechanism (4), a contact system (7), a tripping device (19) and a buffer assembly (20) arranged on the frame, and also comprises an arc extinguishing device (5) and a magnetic blowing device (6) arranged above the contact system (7); the operating mechanism (4) comprises a shift fork assembly (22); the arc extinguishing device (5) is connected to the arc striking angle of the contact system (7) through a pawl; the contact system (7) comprises a moving main contact (8) overlapped with the shift fork assembly (22) and a static main contact (9) adapted to the moving main contact (8); the moving main contact (8) is connected to the moving arc contact (10) through a soft connection (14); the moving main contact (8) is connected to the buffer The top of the impulse assembly (20) is in contact, an arc contact bracket (12) is provided on the moving main contact (8), the bottom of the arc contact bracket (12) is connected to the arc contact support shaft (17), the moving arc contact (10) is connected to the arc contact bracket (12) through the rotating shaft (13), and a static arc contact (11) is provided on the static main contact (9). The arc striking angle includes a static arc striking angle (16) provided on the static arc contact (11) and a dynamic arc striking angle (15) provided on the moving arc contact (10), and a spring or / and disc spring for providing a closing force between the moving arc contact (10) and the static arc contact (11) is provided between the moving arc contact (10) and the arc contact support shaft (17).

2. A DC fast circuit breaker according to claim 1, characterized in that: The frame includes a main frame (3) and a cover plate (34); the contact system (7), the tripping device (19) and the buffer assembly (20) are arranged inside the main frame (3); the arc extinguishing device (5) is arranged on the cover plate (34); the magnetic blowing device (6) is arranged below the cover plate (34) and is insulated from the contact system (7); the operating mechanism (4) and the buffer assembly (20) are arranged on the same side of the main frame (3); and the contact system (7) is connected to the magnetic blowing device (6) through the mounting base (18) to form a magnetic / electric circuit.

3. A DC fast circuit breaker according to claim 2, characterized in that: The contact system (7) further comprises a static main contact copper bar (1) and a lower copper bar (2) mounted on the main frame (3), and a heat transfer component (30) connected to the iron core (25) via a longitudinal connecting bar (29), and a tripping device (19) surrounds the lower copper bar (2).

4. A DC fast circuit breaker according to claim 2, characterized in that: It also includes an auxiliary switch box assembly (21) mounted on the main frame (3), wherein the auxiliary switch box assembly (21) includes an opening and closing indicator, an aviation plug and a micro switch, is located below the operating mechanism (4) and contacts the buffer assembly (20).

5. A DC fast circuit breaker according to claim 1, 2, 3 or 4, characterized in that: The magnetic blowing device (6) includes a base (26) and an iron core (25) symmetrically mounted on both sides of the base (26) and magnetically connected to the moving arc horn (15) through a transverse connecting row (28). The iron core (25) is connected to a magnetic conductive plate (23) located on both sides of the static arc contact (11) and the moving arc contact (10). A magnetic blowing coil (24) is wound around the iron core (25). The two coils (24) are connected through the transverse connecting row (28). The two iron cores (25) are connected by a magnetic base (26). The base (26) and the transverse connecting row (28) are separated by an insulating partition (27). The coil (24) is connected to a heat transfer component (30) through a longitudinal connecting row (29).

6. A DC fast circuit breaker according to claim 5, characterized in that: The operating mechanism (4) further comprises an electromagnet assembly and a wear indicator assembly, wherein the wear indicator assembly is arranged at the tail of the electromagnet assembly, and the shift fork assembly (22) is arranged at the head of the electromagnet assembly.

7. A DC fast circuit breaker according to claim 6, characterized in that: The arc extinguishing device (5) comprises a backing plate arranged on a cover plate (34) and an arc extinguishing chamber located on the backing plate, wherein the arc extinguishing chamber has a V-shaped opening at the bottom, and the arc extinguishing chamber has staggered arc extinguishing grids and insulating grids placed above the arc extinguishing grids.

8. A DC fast circuit breaker according to claim 7, characterized in that: An insulating block is arranged near the main frame (3) and the moving arc contact (10), the moving arc striking angle (15) and the static arc striking angle (16) are wrapped with a ferromagnetic shell, and the magnetic conductive plate (23) is arranged at the connection between the moving arc contact (10), the static arc contact (11) and the moving arc striking angle (15), and the static arc striking angle (16). The bottom end of the magnetic conductive plate (23) is lower than the point / line contact part of the moving arc contact (10) and the static arc contact (11). The front end of the moving arc contact (10) is inserted into the arc contact bracket (12), the tail end is clamped into the clamping piece (35), and then inserted into the arc contact support shaft (17) together.

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