Arc extinguishing system of direct-current circuit breaker

Abstract

The arc extinguishing system of the direct-current circuit breaker comprises an arc extinguishing chamber, a static contact and a moving contact which are installed in a shell of the circuit breaker and are sequentially arranged in the first direction, and further comprises two permanent magnets which are arranged in the third direction and located on the two sides of the static contact, and the permanent magnets are arranged opposite to an arc inlet of the arc extinguishing chamber. The polarities of the opposite sides of the two permanent magnets are the same; and when the movable contact and the static contact are disconnected, the rotating plate rotates to the position between the movable contact and the static contact in the direction close to the permanent magnet. According to the arc extinguishing system of the direct-current circuit breaker, the rotating plate is rotatably arranged between the disconnected movable contact and static contact, so that an electric arc is blocked, and the electric arc is stretched downwards under the common cooperation of the rotating plate and the two permanent magnets which are arranged at the two sides of the static contact and have opposite polarities; the problem that the electric arc cannot be quickly extinguished due to the fact that the magnetic blow-out force of the contact area of the bidirectional non-polar direct-current miniature circuit breaker is small under the critical load current and the electric arc arcing time is long can be effectively solved.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, and particularly to an arc extinguishing system for a DC circuit breaker. Background Art

[0002] The electrodynamic force F received by a DC arc is F = BIL·sinθ, where I is the current, B is the magnetic induction intensity of the magnetic field, and L is the arc column length. The larger the current, the greater the electrodynamic force, which is beneficial to pulling the arc towards the arc extinguishing chamber; the smaller the current, the smaller the electrodynamic force, which is not conducive to pulling the arc towards the arc extinguishing chamber. Since the magnetic release of the existing circuit breaker is solenoid type, as Figure 9 shown, B and I will generate a Lorentz force F perpendicular to the inside. According to the formula, the force received by the arc column is related to the magnetic flux density at the arc, the current magnitude, the length of the conductor, and the angle between the magnetic field and the current. Among them, I is fixed. Since it is a same-direction comparison, the arc column length L is also unified as a fixed value. The magnetic field direction generated by the solenoid is non-deviating orthogonal to the arc column at the arc column, and the included angle is small, so sinθ is small, resulting in a small magnetic blowing force.

[0003] When a small current within a certain range cannot extinguish the arc during normal opening and closing, and the magnetic blowing force is small, the driving force for the arc movement is weak, and the arc cannot enter the arc extinguishing chamber. As a result, the arc extinguishing chamber cannot play its role, and the arc cannot be quickly transferred and extinguished. At this time, the arc will stagnate and continue to burn for a long time, significantly prolonging the opening time or even causing opening failure. This is the reason for the generation of the critical load current. For a DC circuit breaker with a fixed polarity, a permanent magnet is often placed to enhance the magnetic blowing force in the direction opposite to the current and improve the opening ability of the critical load current. However, in a two-way non-polar DC mini circuit breaker, it will be more difficult to improve the opening ability of the critical load current. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome at least one defect of the prior art and provide an arc extinguishing system for a DC circuit breaker.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] DC circuit breaker arc extinguishing system, comprising an arc extinguishing chamber, a static contact and a moving contact which are installed in the housing of the circuit breaker and arranged in sequence along a first direction. The arc extinguishing chamber has an upper region and a lower region arranged along a second direction. The static contact is oppositely arranged with respect to the upper region of the arc extinguishing chamber and is provided with a static contact point. The moving contact is provided with a moving contact point which cooperates with the static contact point. The first direction, the second direction and the third direction are perpendicular to each other. The arc extinguishing system further comprises two permanent magnets which are arranged along the third direction and located on both sides of the static contact. The permanent magnets are oppositely arranged with respect to the arc inlet of the arc extinguishing chamber. The polarities of the opposite sides of the two permanent magnets are the same. The DC circuit breaker arc extinguishing system further comprises a rotating plate rotatably arranged in the housing. When the moving contact point and the static contact point are disconnected, the rotating plate rotates towards the direction close to the permanent magnets until it is between the moving contact point and the static contact point.

[0007] Optionally, the rotating plate comprises a mounting portion for rotatable mounting and a blocking portion for blocking between the moving contact point and the static contact point. The blocking portion is in the structure of an arc-shaped plate.

[0008] Optionally, it further comprises two magnetic conductive plates. The two permanent magnets are respectively arranged on the two magnetic conductive plates. The permanent magnets are oppositely arranged with respect to the lower region of the arc extinguishing chamber.

[0009] Optionally, the permanent magnets are inclined such that the side of the permanent magnets close to the static contact is away from the arc extinguishing chamber and the side away from the static contact is close to the arc extinguishing chamber.

[0010] Optionally, an installation groove is provided at the middle position of the magnetic conductive plate. The permanent magnet is placed in the installation groove of the magnetic conductive plate.

[0011] Optionally, the magnetic field intensity of one of the two permanent magnets is greater than or equal to that of the other permanent magnet.

[0012] Optionally, the permanent magnet is in the structure of a square block.

[0013] Optionally, an arc isolation plate is provided between the opposite sides of the two magnetic conductive plates and the housing respectively.

[0014] Optionally, it further comprises an arc ignition plate. An arc running path is formed by enclosing between the arc ignition plate, the moving contact at the disconnected position, the static contact and the lower region of the arc extinguishing chamber. The permanent magnet is located in the arc running path.

[0015] Optionally, the arc ignition plate comprises a straight portion arranged along the first direction and a bent portion connected to the straight portion. The straight portion is arranged in sequence with the arc extinguishing chamber along the second direction, and the straight portion is close to the lower region of the arc extinguishing chamber and away from the upper region of the arc extinguishing chamber. The bent portion extends towards the moving contact at the disconnected position.

[0016] Optionally, the permanent magnet is inclined, and the end of the bent portion connected to the straight portion is inclined and arranged in parallel and spaced apart from the permanent magnet.

[0017] Optionally, the two permanent magnets are respectively arranged on the opposite side walls of the housing of the circuit breaker, and the permanent magnets are arranged opposite to the upper region of the arc extinguishing chamber.

[0018] Optionally, the permanent magnet is a rectangular block structure, and the length direction of the permanent magnet is arranged along the first direction and the width direction is arranged along the second direction.

[0019] The arc extinguishing system of the DC circuit breaker of the present invention not only blocks the arc by rotating the rotating plate disposed between the moving contact and the static contact in the open state, but also cooperates with the two permanent magnets with opposite polarities disposed on both sides of the static contact to elongate the arc downward, effectively solving the problem that the magnetic blow force in the contact area of the bidirectional non-polar DC miniature circuit breaker is small under the critical load current and the arc cannot be quickly extinguished due to the long arc burning time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the internal structure of the circuit breaker base of the present invention;

[0021] Figure 2 is a schematic diagram of the internal structure of the circuit breaker base of the present invention excluding the magnetic conduction plate;

[0022] Figure 3 is a schematic diagram of the internal structure of the upper cover of the circuit breaker of the present invention;

[0023] Figure 4 is a schematic diagram of the internal structure of the upper cover of the circuit breaker of the present invention excluding the magnetic conduction plate;

[0024] Figure 5 is a schematic diagram of the arc direction and the magnetic induction line direction of the present invention;

[0025] Figure 6 is a schematic diagram of the magnetic induction line path of the present invention;

[0026] Figure 7 is an exploded view of the magnetic conduction plate and the permanent magnet of the present invention;

[0027] Figure 8 is an assembly diagram of the magnetic conduction plate and the permanent magnet of the present invention;

[0028] Figure 9 is a schematic diagram of the influencing factors of the magnetic blow force generated by the solenoid in the background art;

[0029] Figure 10 is a schematic diagram of the internal structure of the circuit breaker base of another embodiment of the present invention;

[0030] Figure 11 is a schematic diagram of the internal structure of the upper cover of the circuit breaker of another embodiment of the present invention;

[0031] Figure 12 It is a schematic diagram of the magnetic induction line direction and Lorentz force direction of another embodiment of the present utility model.

[0032] Base 1; static contact 2; static contact point 21; moving contact 3; moving contact point 31; rotating plate 4; mounting portion 41; blocking portion 42; arc guiding plate 5; straight portion 51; bending portion 52; permanent magnet 6; magnetic conductive plate 7; mounting groove 71; arc separating plate 8; arc extinguishing chamber 9; upper cover 10. Specific embodiments

[0033] The following embodiments given in conjunction with the drawings further illustrate the specific embodiments of the arc extinguishing system of the DC circuit breaker of the present utility model. The arc extinguishing system of the DC circuit breaker of the present utility model is not limited to the description of the following embodiments.

[0034] As Figures 1-4 shown, the arc extinguishing system of the DC circuit breaker in this embodiment includes an arc extinguishing chamber 9, a static contact 2, and a moving contact 3 that are installed in the housing of the circuit breaker and arranged in sequence along the first direction. The housing includes a base 1 and an upper cover 10 that cover each other. The circuit breaker further includes an operating mechanism that is connected to the moving contact 3. The operating mechanism can drive the moving contact 3 to rotate to close or disconnect from the static contact 2, so that the main circuit of the circuit breaker is connected or disconnected, thereby realizing the closing or tripping of the circuit breaker. The circuit breaker further includes a thermal release for overload protection and a magnetic release for short-circuit protection. The thermal release is usually a bimetallic strip and is connected in series to the main circuit of the circuit breaker by being electrically connected between the moving contact 3 and a wiring terminal of the circuit breaker. The magnetic release is arranged above the arc extinguishing chamber 9 and includes a solenoid-type coil, which is connected in series to the main circuit of the circuit breaker by being electrically connected between the static contact 2 and another wiring terminal of the circuit breaker. When an overload or short-circuit fault occurs in the main circuit of the circuit breaker, the thermal release or the magnetic release causes the operating mechanism to trip, driving the moving contact 3 to rotate and disconnect from the static contact 2, thereby realizing the tripping of the circuit breaker and being in a state where it cannot be normally closed. The technologies of closing, tripping, and opening of the circuit breaker are prior arts and will not be elaborated here.

[0035] As Figures 1-4 shown, the arc extinguishing chamber 9, the static contact 2, and the moving contact 3 are installed in the housing and arranged in sequence along the first direction. The arc extinguishing chamber 9 is used to extinguish the arc generated during the opening and closing of the moving contact 3 and the static contact 2, and has an upper region and a lower region arranged along the second direction. The side of the arc extinguishing chamber 9 facing the static contact 2 is the arc inlet of the arc extinguishing chamber 9. The static contact 2 is disposed opposite to the upper region of the arc extinguishing chamber 9 and is provided with a static contact point 21 facing away from the arc extinguishing chamber 9. The moving contact 3 is provided with a moving contact point 31 that cooperates with the static contact point 21.

[0036] The first direction, the second direction, and the third direction are perpendicular to each other, so as to Figure 1For example, the first direction is the left - right direction in the figure, which is also the length direction of the circuit breaker. The second direction is the up - down direction in the figure, which is also the height direction of the circuit breaker. The third direction is the direction perpendicular to the drawing, which is also the thickness direction of the circuit breaker.

[0037] Specifically, the arc - extinguishing system of the DC circuit breaker in this embodiment further includes two magnetic - conducting plates 7 arranged along the third direction and located on both sides of the static contact 2. The two magnetic - conducting plates 7 are symmetrically arranged. One magnetic - conducting plate 7 is inside the base 1 of the housing, and the other magnetic - conducting plate 7 is inside the upper cover 10 of the housing. The width direction of the magnetic - conducting plate 7 is along the first direction, and the length direction is along the second direction. A permanent magnet 6 is provided at the middle position of each of the two magnetic - conducting plates 7. The magnetic - conducting plate 7 is arranged opposite to the arc - extinguishing chamber 9, and the permanent magnet 6 on the magnetic - conducting plate 7 is arranged opposite to the arc - inlet of the arc - extinguishing chamber 9. The polarities of the two permanent magnets 6 on the two magnetic - conducting plates 7 facing each other are the same, that is, the N - poles of the two permanent magnets 6 face each other, or the S - poles of the two permanent magnets 6 face each other.

[0038] The arc - extinguishing system of the DC circuit breaker in this embodiment further includes an arc - guiding plate 5. A running - arc path is formed by enclosing between the arc - guiding plate 5, the moving contact 3 in the open position, the static contact 2, and the lower region of the arc - extinguishing chamber 9. The magnetic - conducting plate 7 and the permanent magnet 6 are located in the running - arc path. Specifically, the arc - guiding plate 5 includes a straight part 51 arranged along the first direction and a bent part 52 connected to the straight part 51. The magnetic release, the arc - extinguishing chamber 9, and the straight part 51 are arranged along the second direction, that is, the straight part 51 is close to the lower region of the arc - extinguishing chamber 9 and far from the upper region of the arc - extinguishing chamber 9. The bent part 52 extends towards the moving contact 3 in the open position. The bent part 52 is preferably a folded - plate structure with an obtuse - angle, and can also be an arc - shaped plate structure or other structures. An arc - guiding angle is provided at one end of the static contact 2, which bends from the static contact point 21 into the arc - extinguishing chamber 9. The arc - guiding angle extends between the two magnetic - conducting plates 7, and the end extends into the arc - extinguishing chamber 9. The permanent magnet 6 is located between the arc - guiding angle and the bent part 52.

[0039] As Figure 5 and Figure 6 shown, the arc enters the gap between the two magnetic - conducting plates 7 from above and then moves to both sides. Under the action of the magnetic - blowing force of the permanent magnet 6 on the magnetic - conducting plate 7, the arc is stretched downward (the second direction) along the magnetic - conducting plate 7, and the arc can jump onto the arc - guiding plate 5. In the arc - extinguishing system of the DC circuit breaker in this embodiment, by arranging the same polarities of the two permanent magnets 6 located on both sides of the static contact 2 and opposite to the lower region of the arc - extinguishing chamber 9 facing each other, a strong external magnetic field is increased in the contact area, enhancing the longitudinal arc - drawing, improving the critical load - current breaking ability, and being not affected by the current direction, which is applicable to bidirectional non - polar DC small - sized circuit breakers.

[0040] As Figure 7 and Figure 8As shown, the permanent magnet 6 is inclined such that the side of the permanent magnet 6 close to the static contact 2 is away from the arc extinguishing chamber 9, and the side away from the static contact 2 is close to the arc extinguishing chamber 9, that is, the upper side of the permanent magnet 6 is away from the arc extinguishing chamber 9 and the lower side is close to the arc extinguishing chamber 9. The inclination of the permanent magnet 6 makes one side closer to the arc generation position and the other side closer to the arc extinguishing chamber 9, which is more conducive to blowing the arc into the arc extinguishing chamber 9, improving the arc extinguishing effect and breaking capacity of the circuit breaker. Further, as Figure 1 and Figure 3 shown, the end of the bent portion 52 connected to the straight portion 51 is inclined and arranged in parallel and spaced apart from the permanent magnet 6 to place the permanent magnet 6 at the middle position of the arc running path, so as to keep the magnetic field between the static contact 2 and the moving contact 3 uniform.

[0041] As Figure 7 and Figure 8 shown, an installation groove 71 is provided at the middle position of the magnetic conductive plate 7, and the permanent magnet 6 is placed in the installation groove 71 of the magnetic conductive plate 7. By providing the installation groove 71 on the magnetic conductive plate 7, the permanent magnet 6 is limited and installed on the magnetic conductive plate 7, with a simple structure and convenient installation. Of course, the permanent magnet 6 can also be installed on the magnetic conductive plate 7 by means of clamping, bonding and other fixing methods. Preferably, the permanent magnet 6 is of a square block structure, and one corner is rounded. The structure of the permanent magnet 6 in this embodiment is extremely simple and convenient for production and manufacturing. Of course, the permanent magnet 6 can also be trapezoidal, triangular and other shapes.

[0042] As Figure 1 and Figure 3 shown, the magnetic field intensity of one of the two permanent magnets 6 is greater than or equal to the magnetic field intensity of the other permanent magnet 6. In this embodiment, the magnetic field intensity of the permanent magnet 6 on the magnetic conductive plate 7 in the base 1 is greater than or equal to the magnetic field intensity of the permanent magnet 6 on the magnetic conductive plate 7 in the upper cover 10. By changing the size of the permanent magnet 6, different magnetic field intensities are achieved. The size of the permanent magnet 6 in the base 1 is set to be larger than the size of the permanent magnet 6 in the upper cover 10 to make the magnetic field intensity of the permanent magnet 6 in the base 1 greater than the magnetic field intensity of the permanent magnet 6 in the upper cover 10; the two permanent magnets 6 are set to be the same size to make the magnetic field intensities of the two permanent magnets 6 the same.

[0043] The arc extinguishing system of the DC circuit breaker in this embodiment further includes a rotating plate 4 rotatably arranged on the base 12 in the housing. When the moving contact 31 and the static contact 21 are disconnected, the rotating plate 4 rotates towards the direction close to the permanent magnet 6 to between the moving contact 31 and the static contact 21. Specifically, the rotating plate 4 includes an installation portion 41 for rotational installation and a blocking portion 42 for blocking between the moving contact 31 and the static contact 21, and the blocking portion 42 is of an arc-shaped plate structure. As Figure 1 and Figure 2As shown, when the moving contact 31 is closed with the static contact 21, the rotating plate 4 rotates clockwise to avoid the moving contact 3; when the moving contact 31 is disconnected from the static contact 21, the rotating plate 4 rotates counterclockwise towards the arc guiding plate 5 to between the moving contact 31 and the static contact 21. By rotating the rotating plate 4 disposed between the disconnected moving contact 31 and the static contact 21, not only the arc is blocked and the arc is elongated downward, but also in cooperation with two permanent magnets 6 with opposite polarities disposed on both sides of the static contact 2, the arc is elongated downward, making it conducive for the arc to jump onto the arc guiding plate 5, which can effectively solve the problem that the magnetic blow force in the contact area of the bidirectional non-polar DC miniature circuit breaker is small under the critical load current and the arc cannot be quickly extinguished due to the long arc burning time.

[0044] There can be various ways for the driving structure of the rotating plate 4. A preferred way is that the arc extinguishing system of the DC circuit breaker further includes a rotatably disposed contact support, a pushing mechanism for driving the rotation of the rotating plate 4, and a return spring. The moving contact 3 is rotatably disposed on the contact support, and the moving contact 3 and the contact support are connected by a contact spring to achieve overtravel. The pushing mechanism in this embodiment is the contact support, and the return spring is used to push the rotating plate 4 to rotate between the moving contact 3 and the static contact 2 to be in the arc isolating position (that is, the blocking portion 42 of the rotating plate 4 blocks between the moving contact 31 and the static contact 21). During closing, that is, when the contact support drives the moving contact 3 to contact the static contact 2, the pushing mechanism can drive the rotating plate 4 to move away from between the moving contact 3 and the static contact 2 so that the rotating plate 4 is in the non-arc isolating position. Before the rotating plate 4 moves away from between the moving contact 3 and the static contact 2, that is, during the process of the rotating plate 4 rotating from the arc isolating position to the non-arc isolating position, it can block the moving contact 3, causing the moving contact 3 and the contact support to rotate relative to each other. When the rotation of the rotating plate 4 releases the block on the moving contact 3, the contact spring releases energy to drive the moving contact 3 to quickly contact the static contact 2; when the rotating plate 4 rotates to the non-arc isolating position, it releases the block on the moving contact 3, or releases the block on the moving contact 3 during the rotation to the non-arc isolating position. As other embodiments, the rotation of the rotating plate 4 can be driven by the moving contact 3, or by a handle or an operating mechanism.

[0045] As Figure 2 and Figure 4 shown, an arc isolating plate 8 is provided between the opposite sides of the two magnetic conduction plates 7 and the housing, that is, as Figure 2 shown, an arc isolating plate 8 is provided between one magnetic conduction plate 7 and the base 1 of the housing, as Figure 4 shown, an arc isolating plate 8 is also provided between the other magnetic conduction plate 7 and the upper cover 10 of the housing.

[0046] As Figures 10-12As shown, another embodiment of the arrangement of the permanent magnet 6 in the present application is mainly different from the above embodiment in that the magnetic conductive plate 7 is not provided, and the permanent magnet 6 is directly arranged on the housing of the circuit breaker. The two permanent magnets 6 are respectively arranged on the opposite side walls of the housing of the circuit breaker, that is, one permanent magnet 6 is arranged on the bottom plate of the base 1 of the housing, and the other permanent magnet 6 is arranged on the top plate of the upper cover 10 of the housing. The permanent magnet 6 is arranged opposite to the upper region of the arc extinguishing chamber 9 and is located below the static contact 21. In this embodiment, the arc guiding angle of the static contact 2 extends from the static contact 21 between the two permanent magnets 6, and the end extends into the arc extinguishing chamber 9. The permanent magnet 6 in this embodiment is preferably a rectangular block structure, and the length direction of the permanent magnet 6 is arranged along the first direction and the width direction is arranged along the second direction, that is, the permanent magnet 6 is horizontally arranged between the upper region of the arc extinguishing chamber 9 and one end of the arc guiding plate 5 close to the moving contact 3.

[0047] As Figure 1 and Figure 2 shown, the working principle of the arc extinguishing system of the DC circuit breaker is that the critical load current will quickly extinguish after transferring from between the moving contact 3 and the static contact 2 to the arc guiding plate 5, and the arc energy is not sufficient to maintain its transfer into the arc extinguishing chamber 9. When the circuit breaker is closed, the moving contact 3 rotates clockwise until the moving contact point 31 contacts and closes with the static contact point 21. At the same time, the moving contact 3 drives the rotating plate 4 to rotate clockwise until the rotating plate 4 is located in the gap on the upper side surface of the moving contact point 31; when the circuit breaker is opened, the moving contact 3 drives the rotating plate 4 to rotate counterclockwise. At this time, an arc is generated between the moving contact 3 and the static contact 2. As the moving contact 3 continues to open, the rotating plate 4 rotates between the moving contact point 31 and the static contact point 21. The rotating plate 4 plays a role in blocking the arc and stretching the arc downward. However, the self-excited magnetic field generated between the moving contact 3 and the static contact 2 under the critical load current is weak and cannot quickly transfer the arc to the arc guiding plate 5. Since the polarities of the two permanent magnets 6 are opposite, an opposing arc blowing magnetic field is generated in the contact area. Ideally, the Lorentz forces cancel each other out in the middle of the arc blowing magnetic field, the Lorentz force is greater in the area closer to the upper cover 10, and the Lorentz force is also greater in the area closer to the base 1. The arc between the moving contact 3 and the static contact 2 is continuously stretched longitudinally (along the length direction of the two magnetic conductive plates) under the blocking and downward stretching of the rotating plate 4. At this time, the arc either directly extinguishes quickly or quickly transfers to the arc guiding plate 5 and transfers to the arc extinguishing chamber 9, thereby accelerating the arc extinguishing.

[0048] It should be noted that in the description of the present utility model, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which it is usually placed during use. It is only for the convenience of description and does not indicate that the device or component referred to must have a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be construed as indicating relative importance.

[0049] The above content is a further detailed description of the present utility model in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present utility model is only limited to these descriptions. For those of ordinary skill in the technical field to which the present utility model belongs, without departing from the concept of the present utility model, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present utility model.

Claims

1. A DC circuit breaker arc extinguishing system, comprising an arc extinguishing chamber (9), a stationary contact (2) and a moving contact (3) which are installed in a housing of the circuit breaker and arranged in sequence along a first direction, characterized in that: The arc extinguishing chamber (9) has an upper region and a lower region arranged along the second direction; the static contact (2) is arranged opposite to the upper region of the arc extinguishing chamber (9) and is provided with a static contact (21); the movable contact (3) is provided with a movable contact (31) matched with the static contact (21); the first direction, the second direction and the third direction are perpendicular to each other; the arc extinguishing system further comprises two permanent magnets (6) arranged along the third direction and located on both sides of the static contact (2); the permanent magnets (6) are arranged opposite to the arc inlet of the arc extinguishing chamber (9); and the polarities of the two permanent magnets (6) facing each other are the same; The DC circuit breaker arc extinguishing system also includes a rotating plate (4) rotatably arranged in the housing, and when the moving contact (31) and the stationary contact (21) are disconnected, the rotating plate (4) rotates in a direction close to the permanent magnet (6) to between the moving contact (31) and the stationary contact (21).

2. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: The rotating plate (4) comprises a mounting portion (41) for rotational mounting and a blocking portion (42) for blocking between the moving contact (31) and the stationary contact (21); the blocking portion (42) is an arc-shaped plate structure.

3. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: It also comprises two magnetic conductive plates (7), the two permanent magnets (6) are respectively arranged on the two magnetic conductive plates (7), and the permanent magnets (6) are arranged opposite to the lower area of ​​the arc extinguishing chamber (9).

4. The DC circuit breaker arc extinguishing system according to claim 3, characterized in that: The permanent magnet (6) is arranged tilted so that the side of the permanent magnet (6) close to the stationary contact (2) is away from the arc extinguishing chamber (9), and the side away from the stationary contact (2) is close to the arc extinguishing chamber (9).

5. The DC circuit breaker arc extinguishing system according to claim 3, characterized in that: A mounting groove (71) is provided in the middle of the magnetic conductive plate (7), and the permanent magnet (6) is placed in the mounting groove (71) of the magnetic conductive plate (7).

6. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: The magnetic field strength of one of the two permanent magnets (6) is greater than or equal to the magnetic field strength of the other permanent magnet (6).

7. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: The permanent magnet (6) is a square block structure.

8. The DC circuit breaker arc extinguishing system according to claim 3, characterized in that: An arc isolation plate (8) is respectively arranged between the opposite sides of the two magnetic conductive plates (7) and the housing.

9. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: It also comprises an arc striking plate (5), wherein an arc running track is formed between the arc striking plate (5), the moving contact (3) in the disconnected position, the stationary contact (2) and the lower area of ​​the arc extinguishing chamber (9), and the permanent magnet (6) is located in the arc running track.

10. The DC circuit breaker arc extinguishing system according to claim 9, characterized in that: The arc-starting plate (5) comprises a straight portion (51) arranged along a first direction and a bent portion (52) connected to the straight portion (51); the straight portion (51) and the arc-extinguishing chamber (9) are arranged in a second direction, and the straight portion (51) is close to a lower area of ​​the arc-extinguishing chamber (9) and away from an upper area of ​​the arc-extinguishing chamber (9); and the bent portion (52) extends toward the moving contact (3) in a disconnected position.

11. The DC circuit breaker arc extinguishing system according to claim 10, characterized in that: The permanent magnet (6) is arranged obliquely, and one end of the bent portion (52) connected to the straight portion (51) is arranged obliquely and is arranged parallel to and spaced from the permanent magnet (6).

12. The DC circuit breaker arc extinguishing system according to claim 1, characterized in that: The two permanent magnets (6) are respectively arranged on two opposite side walls of a housing of the circuit breaker, and the permanent magnets (6) are arranged opposite to an upper area of ​​an arc extinguishing chamber (9).

13. The DC circuit breaker arc extinguishing system according to claim 12, characterized in that: The permanent magnet (6) is a rectangular block structure, and the length direction of the permanent magnet (6) is arranged along a first direction, and the width direction is arranged along a second direction.

Images