Arc extinguishing device of circuit breaker and circuit breaker

Abstract

The application relates to the field of low-voltage electrical apparatus, in particular to an arc extinguishing device of a circuit breaker and a circuit breaker comprising the arc extinguishing device, wherein the arc extinguishing chamber of the arc extinguishing device comprises a grid piece group, the grid piece group comprises a plurality of grid pieces arranged side by side along the length direction of the arc extinguishing chamber; the arc entrance and the exhaust port of the arc extinguishing chamber are located at two ends of the arc extinguishing chamber in the height direction of the arc extinguishing chamber, the arc entrance is used for cooperating with the contact mechanism of the circuit breaker; in the length direction of the arc extinguishing chamber, the arc extinguishing chamber is divided into two parts, namely the left part of the arc extinguishing chamber and the right part of the arc extinguishing chamber; the magnetic field generating device of the arc extinguishing device comprises a permanent magnet group, the permanent magnet group comprises a left magnet group and a right magnet group with opposite magnetic field directions, and in the width direction of the arc extinguishing chamber, the left magnet group is arranged side by side with the left part of the arc extinguishing chamber, and the right magnet group is arranged side by side with the right part of the arc extinguishing chamber; the arc extinguishing device and the circuit breaker improve the breaking performance of the circuit breaker, and can extinguish both alternating current arcs and direct current arcs.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical appliances, and more specifically to an arc-extinguishing device for a circuit breaker and a circuit breaker including the arc-extinguishing device. Background Technology

[0002] Miniature circuit breakers generally include an operating mechanism, a contact mechanism, and an arc-extinguishing chamber. The contact mechanism is achieved by working moving contacts and stationary contacts. The operating mechanism drives the moving contact to swing and contact the stationary contact to close or open, thereby realizing the closing or opening of the miniature circuit breaker.

[0003] Existing miniature circuit breakers often have the following problems:

[0004] 1. In order to achieve rapid arc stretching and extinguishing and improve the breaking performance of circuit breakers, the following methods are often used: increasing the opening distance between the moving contact and the stationary contact. A common practice is to increase the size of the circuit breaker to provide more space for the contact mechanism. However, this will not only increase production costs, but also reduce the reliability of the circuit breaker closing.

[0005] 2. Its arc-extinguishing chamber has limited arc-extinguishing capacity, and most of it can only be used to extinguish AC arcs.

[0006] 3. Relying solely on the separation of moving and stationary contacts and the arc-extinguishing chamber to extinguish the arc has limited arc-extinguishing capability. Summary of the Invention

[0007] The purpose of this invention is to overcome at least one defect of the prior art and provide an arc extinguishing device for a circuit breaker and a circuit breaker including the arc extinguishing device, which improves the breaking performance of the circuit breaker and can extinguish both AC and DC arcs.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An arc-extinguishing device for a circuit breaker includes an arc-extinguishing chamber, which includes a grid plate group, which includes multiple grid plates arranged side by side along the length of the arc-extinguishing chamber; the arc-extinguishing chamber includes an arc inlet and an exhaust outlet located at both ends of the arc-extinguishing chamber in the height direction of the arc-extinguishing chamber, and the arc inlet is used to cooperate with the contact mechanism of the circuit breaker.

[0010] Along the length of the arc-extinguishing chamber, the arc-extinguishing chamber is divided into two parts, namely the left part of the arc-extinguishing chamber and the right part of the arc-extinguishing chamber;

[0011] The arc-extinguishing device also includes a magnetizing device, which includes a permanent magnet group, a left magnet group and a right magnet group. The magnetic field directions of the left magnet group and the right magnet group are opposite. In the width direction of the arc-extinguishing chamber, the left magnet group is arranged side by side with the left side of the arc-extinguishing chamber, and the right magnet group is arranged side by side with the right side of the arc-extinguishing chamber.

[0012] Furthermore, the left magnet group includes a left rear magnet and a left front magnet, and the right magnet group includes a right rear magnet and a right front magnet;

[0013] In the width direction of the arc-extinguishing chamber, the left rear magnet and the left front magnet are located on both sides of the left part of the arc-extinguishing chamber, and the right rear magnet and the right front magnet are located on both sides of the right part of the arc-extinguishing chamber; the magnetic field direction between the left rear magnet and the left front magnet is opposite to the magnetic field direction between the right rear magnet and the right front magnet.

[0014] Furthermore, the arc-extinguishing chamber is located entirely within the magnetic field of the permanent magnet assembly, and the permanent magnet assembly is also used to cover the contacts of the contact mechanism.

[0015] Furthermore, the magnetizing device also includes an isolation plate assembly, which includes a rear isolation plate and a front isolation plate. In the width direction of the arc-extinguishing chamber, the rear isolation plate and the front isolation plate are located on both sides of the arc-extinguishing chamber, and the isolation plate assembly is disposed between the arc-extinguishing chamber and the permanent magnet assembly.

[0016] Furthermore, the arc extinguishing device also includes a left arc-inducing plate and a right arc-inducing plate. In the length direction of the arc extinguishing chamber, the left arc-inducing plate and the right arc-inducing plate are located on both sides of the grid plate group and arranged side by side with the grid plate group.

[0017] Furthermore, in the height direction of the arc-extinguishing chamber, one end of the left and right arc-initiating plates extends towards the exhaust port of the arc-extinguishing chamber and is arranged side by side with the grid plate group. The other ends of the left and right arc-initiating plates extend away from the exhaust port of the arc-extinguishing chamber, protruding on one side of the arc-extinguishing chamber to form a contact space for accommodating the contacts of the contact mechanism. The left arc-initiating plate, the magnetizing device, and the right arc-initiating plate form a magnetic field space, and the contacts of the contact mechanism and the arc-extinguishing chamber are located within the magnetic field space.

[0018] Furthermore, the magnetizing device also includes a magnetic guide plate assembly, which includes a rear magnetic guide plate and a front magnetic guide plate. In the width direction of the arc-extinguishing chamber, the rear magnetic guide plate and the front magnetic guide plate are located on both sides of the arc-extinguishing chamber.

[0019] Furthermore, in the width direction of the arc-extinguishing chamber, the permanent magnet assembly is disposed between the isolation plate assembly and the magnetic conductive plate assembly.

[0020] Furthermore, the left arc-leading plate, the rear magnetic guide plate, the right arc-leading plate, and the front magnetic guide plate are connected sequentially around the magnetic field space.

[0021] Furthermore, the arc-extinguishing device also includes an arc-isolating plate, which is used to move between the contacts of the contact mechanism when the circuit breaker is tripped.

[0022] Furthermore, the arc-extinguishing chamber also includes mounting plates. Two mounting plates are arranged at intervals relative to each other in the width direction of the arc-extinguishing chamber, and each grid plate is located between the two mounting plates and is connected to the two mounting plates respectively.

[0023] A circuit breaker, the circuit breaker including the arc extinguishing device.

[0024] Furthermore, the contact mechanism includes a left contact and a right contact. In the length direction of the arc-extinguishing chamber, the left contact and the right contact are arranged opposite each other, rotating synchronously towards each other to close and rotating synchronously away from each other to open.

[0025] Furthermore, the arc-extinguishing device's arc-blocking plate is driven to engage with the left or right contact; when the left and right contacts are closed, the arc-blocking plate is driven by the left or right contact to move out of the contact points between the left and right contacts; when the left and right contacts are separated, the arc-blocking plate is driven by the left or right contact to move into the contact points between the left and right contacts.

[0026] The arc-extinguishing device of the circuit breaker of the present invention has magnetic fields in opposite directions in the left and right parts of the arc-extinguishing chamber. This ensures that regardless of whether the circuit breaker is reverse-connected or the direction of the current flowing through the circuit breaker, one of the two magnetic fields will always be able to drive the arc generated by the contact mechanism, lengthen the arc and cause it to move into the arc-extinguishing chamber, thereby improving the arc extinguishing efficiency and enhancing the breaking capacity of the circuit breaker. Therefore, the arc-extinguishing device can be used not only for extinguishing AC arcs but also for extinguishing DC arcs.

[0027] In addition, the arc-isolating plate physically isolates the electric arc, and at the same time, it divides the magnetic field of the magnetizing device into two parts along the length of the arc-extinguishing chamber, significantly improving the arc extinguishing speed on one side of the arc-isolating plate.

[0028] Furthermore, the contact mechanism is implemented by two moving contacts, thereby significantly increasing the opening distance while occupying less space. In conjunction with the arc extinguishing device, it further accelerates the arc extinguishing speed.

[0029] The circuit breaker of the present invention includes the arc extinguishing device, which has good breaking performance and can extinguish both AC and DC arcs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the projected structure of the circuit breaker of the present invention, showing the cooperation relationship between the magnetizing device and the arc-blocking plate;

[0031] Figure 2 This is a cross-sectional structural schematic diagram of the circuit breaker of the present invention, showing the positional relationship of the arc-extinguishing chamber, the isolation plate assembly, the permanent magnet assembly, and the magnetic conductive plate assembly;

[0032] Figure 3 This is an explosion diagram of the arc-extinguishing device of the present invention;

[0033] Figure 4 This is a schematic projection of the circuit breaker of the present invention, showing the magnetic field of the permanent magnet assembly;

[0034] Figure 5 This is a three-dimensional structural diagram of the circuit breaker of the present invention, which is in the closed state;

[0035] Figure 6 This is a three-dimensional structural diagram of the circuit breaker of the present invention, which is in the open state.

[0036] Explanation of reference numerals in the attached figures

[0037] 1. Magnetizing device; 11. Isolation plate assembly; 11a. Rear isolation plate; 11b. Front isolation plate; 12. Permanent magnet assembly; 12a. Left rear magnet; 12b. Left front magnet; 12c. Right rear magnet; 12d. Right front magnet; 13. Magnetic guide plate assembly; 13a. Rear magnetic guide plate; 13b. Front magnetic guide plate; 14. Arc extinguishing chamber; 15a. Left arc-initiating plate; 15b. Right arc-initiating plate; 2. Arc-isolating plate; 3. Contact mechanism; 30. Left contact; 31. Right contact. Detailed Implementation

[0038] The following embodiments, in conjunction with the accompanying drawings, further illustrate specific implementations of the circuit breaker of the present invention. The circuit breaker of the present invention is not limited to the descriptions in the following embodiments.

[0039] It should be noted that in the description of this invention, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship conventionally placed during use. They are used only for ease of description and do not indicate that the device or element referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating relative importance.

[0040] like Figure 1-6 As shown, the circuit breaker of the present invention includes a contact mechanism 3 and an arc extinguishing device. The arc extinguishing device cooperates with the contact mechanism 3 to extinguish the electric arc generated when the contact mechanism 3 closes and opens.

[0041] like Figure 2-3As shown, the arc-extinguishing device includes an arc-extinguishing chamber 14, which includes a grid plate assembly. The grid plate assembly includes multiple grid plates, which are arranged side by side along the length of the arc-extinguishing chamber 14. The arc-extinguishing chamber 14 includes an arc inlet and an exhaust outlet located at both ends of the arc-extinguishing chamber 14 in the height direction. The arc inlet is used to cooperate with the contact mechanism 3 of the circuit breaker. In the length direction of the arc-extinguishing chamber 14, the arc-extinguishing chamber 14 is divided into two parts, namely the left part of the arc-extinguishing chamber and the right part of the arc-extinguishing chamber. The arc-extinguishing device also includes a magnetizing device 1, which includes a permanent magnet assembly 12. The permanent magnet assembly 12 includes a left magnet assembly and a right magnet assembly. In the width direction of the arc-extinguishing chamber 14, the left magnet assembly is arranged side by side with the left part of the arc-extinguishing chamber, and the right magnet assembly is arranged side by side with the right part of the arc-extinguishing chamber. The magnetic fields in the left and right parts of the arc-extinguishing chamber are in opposite directions, thus ensuring that regardless of whether the circuit breaker is reverse-connected or the direction of the current flowing through the circuit breaker, one of the two magnetic fields will always be able to drive the arc generated by the contact mechanism 3, lengthen the arc and cause it to move into the arc-extinguishing chamber 14, thereby improving the arc extinguishing efficiency and enhancing the circuit breaker's breaking capacity. Therefore, the arc-extinguishing device can be used not only for extinguishing AC arcs but also for extinguishing DC arcs.

[0042] like Figure 2-3 As shown, the left magnet group includes a left rear magnet 12a and a left front magnet 12b, and the right magnet group includes a right rear magnet 12c and a right front magnet 12d. In the width direction of the arc-extinguishing chamber 14, the left rear magnet 12a and the left front magnet 12b are located on either side of the left side of the arc-extinguishing chamber, that is, the left rear magnet 12a and the left front magnet 12b are arranged side-by-side with the left side of the arc-extinguishing chamber. The right rear magnet 12c and the right front magnet 12d are located on either side of the right side of the arc-extinguishing chamber, that is, the right rear magnet 12c and the right front magnet 12d are arranged side-by-side with the right side of the arc-extinguishing chamber. The left rear... The poles of magnets 12a and the left front magnet 12b have opposite polarities; that is, one of the poles of the left rear magnet 12a and the left front magnet 12b is the N pole and the other is the S pole. The poles of magnets 12c and the right front magnet 12d have opposite polarities; that is, one of the poles of magnets 12c and the right front magnet 12d is the N pole and the other is the S pole. The direction of the magnetic field between the left rear magnet 12a and the left front magnet 12b is opposite to the direction of the magnetic field between the right rear magnet 12c and the right front magnet 12d.

[0043] Specifically, such as Figure 4-6 As shown in the reverse direction, the vertical direction of the drawing represents the height of the arc-extinguishing chamber 4, the horizontal direction represents the length of the arc-extinguishing chamber 4, and the inward and outward directions of the drawing represent the width of the arc-extinguishing chamber 4.

[0044] like Figure 4As shown, the arc extinguishing chamber 14 is located entirely within the magnetic field of the permanent magnet assembly 12, and the permanent magnet assembly 12 is also used to cover the contacts of the contact mechanism 3. That is, regardless of whether the contacts of the contact mechanism 3 are in a closed state or an open state, they are located within the magnetic field of the permanent magnet assembly 12, thereby ensuring that the electric arc is completely within the range of the magnetic field and improving the efficiency and capability of arc extinguishing.

[0045] like Figure 3-6 As shown, the arc-extinguishing device further includes a left arc-initiating plate 15a and a right arc-initiating plate 15b. Along the length of the arc-extinguishing chamber 14, the left and right arc-initiating plates 15a and 15b are located on both sides of the grid assembly of the arc-extinguishing chamber 14 and arranged side-by-side with the grid assembly, which helps improve the efficiency of the arc entering the arc-extinguishing chamber 14. Furthermore, along the height of the arc-extinguishing chamber 14, one end of the left and right arc-initiating plates 15a and 15b extends towards the exhaust port of the arc-extinguishing chamber 14, and the other end extends away from the exhaust port of the arc-extinguishing chamber 14, protruding from one side of the arc-extinguishing chamber 14 and close to the contact mechanism 3, forming a contact space for accommodating the contacts of the contact mechanism 3. The left arc-initiating plate 15a, the magnetizing device 1, and the right arc-initiating plate 15b form a magnetic field space, within which the contacts of the contact mechanism 3 and the arc-extinguishing chamber 14 are located, thereby improving the arc-extinguishing efficiency. Furthermore, the magnetic field space is a square space.

[0046] Specifically, such as Figure 3-6 As shown, the lower ends of the left arc-inducing plate 15a and the right arc-inducing plate 15b are located on both sides of the grid plate group of the arc-extinguishing chamber 14 and are arranged side by side with it. The upper ends of the left arc-inducing plate 15a and the right arc-inducing plate 15b protrude from the upper side of the arc-extinguishing chamber 14 and are located on the left and right sides of the contact mechanism 3, respectively.

[0047] like Figure 2-6 As shown, the arc-extinguishing chamber 14 also includes mounting plates. Two mounting plates are arranged at intervals relative to each other in the width direction of the arc-extinguishing chamber 14, and each grid plate is located between the two mounting plates and connected to the two mounting plates respectively. Of course, the arc-extinguishing chamber 14 may also be provided without mounting plates, and each grid plate may be fixed on the rear isolation plate 11a and the front isolation plate 11b, thereby reducing the number of parts and reducing production costs.

[0048] like Figure 2-3As shown, the magnetizing device 1 also includes an isolation plate assembly 11, which includes a rear isolation plate 11a and a front isolation plate 11b. In the width direction of the arc-extinguishing chamber 14, the rear isolation plate 11a and the front isolation plate 11b are located on both sides of the arc-extinguishing chamber 14. The isolation plate assembly 11 is disposed between the arc-extinguishing chamber 14 and the permanent magnet 12. The isolation plate assembly 11 separates the arc-extinguishing chamber 14 and the permanent magnet assembly 12, forms a protection for the permanent magnet assembly 12, avoids arc burns to the permanent magnet assembly 12, and extends the service life of the magnetizing device 1. Furthermore, in the width direction of the arc-extinguishing chamber 14, the rear isolation plate 11a is disposed between the arc-extinguishing chamber 14 and the left rear magnet 12a and the right rear magnet 12c, and the front isolation plate 11b is disposed between the arc-extinguishing chamber 14 and the left front magnet 12b and the right front magnet 12d. The left rear magnet 12a, the right rear magnet 12c and the rear isolation plate 11a are located on one side of the arc-extinguishing chamber 14, and the left front magnet 12b, the right front magnet 12d and the front isolation plate 11b are located on the other side of the arc-extinguishing chamber 14.

[0049] like Figure 2-3 As shown, the magnetizing device 1 further includes a magnetic guide plate assembly 13, which includes a rear magnetic guide plate 13a and a front magnetic guide plate 13b. In the width direction of the arc-extinguishing chamber 14, the rear magnetic guide plate 13a and the front magnetic guide plate 13b are located on both sides of the arc-extinguishing chamber 14. The magnetic guide plate assembly 13 can enhance the magnetic field strength of the permanent magnet assembly 12, thereby increasing the driving force for the electric arc and improving the arc-extinguishing efficiency and capability. Furthermore, in the width direction of the arc-extinguishing chamber 14, the rear magnetic guide plate 13a and the front magnetic guide plate 13b are located on both sides of the permanent magnet assembly 12. That is, a left rear magnet 12a and a right rear magnet 12c are provided between the rear magnetic guide plate 13a and the arc-extinguishing chamber 14, and a left front magnet 12b and a right front magnet 12d are provided between the front magnetic guide plate 13b and the arc-extinguishing chamber 14.

[0050] Furthermore, such as Figure 2-3 As shown, the left arc-inducing plate 15a, the rear magnetic guide plate 13a, the right arc-inducing plate 15b, and the front magnetic guide plate 13b are connected in sequence around the magnetic field space, which significantly increases the magnetic field strength in the magnetic field space, further increases the driving force of the magnetic field on the electric arc, and improves the arc extinguishing efficiency and capability.

[0051] like Figure 1 , 5 As shown in Figure -6, the arc-extinguishing device also includes an arc-isolating plate 2. The arc-isolating plate 2 is used to move between the contacts of the contact mechanism 3 when the circuit breaker is open, i.e., when the contact mechanism 3 is broken, thereby physically isolating the arc. Simultaneously, along the length of the arc-extinguishing chamber 4, it divides the magnetic field of the magnetizing device 1 into two parts, significantly improving the arc extinguishing speed on one side of the arc-isolating plate 2. When the circuit breaker is closed, i.e., when the contact mechanism 3 is closed, the arc-isolating plate 2 moves out from between the contacts of the contact mechanism 3, thereby avoiding the contact structure 3 and ensuring reliable closure of the contact mechanism 3. Further, as... Figure 6As shown, when the circuit breaker is tripped, that is, when the contact mechanism 3 is tripped, the arc-blocking plate 2 divides the space between the left arc-leading plate 5a and the right arc-leading plate 5b into two parts along the length of the arc-extinguishing chamber 4.

[0052] like Figure 1 , 4 As shown in Figure 6, the contact mechanism 3 includes a left contact 30 and a right contact 31. Along the length of the arc-extinguishing chamber 4, the left contact 30 and right contact 31 are arranged opposite each other, rotating synchronously towards each other to close and synchronously away from each other to open. This significantly increases the opening distance while occupying less space, and in conjunction with the arc-extinguishing device, further accelerates the arc extinguishing speed. Furthermore, the left contact 30 and right contact 31 are driven together to achieve synchronous rotation. Furthermore, the left contact support of the left contact 30 includes a left gear, and the right contact support of the right contact 31 includes a right gear; the left gear meshes with the right gear. The mechanical transmission between the left contact 30 and right contact 31 ensures the synchronicity and reliability of their operation. Of course, the contact structure 3 can also be set up in a one-stationary-one-moving manner, that is, a stationary contact and a moving contact used together. The structure of the left arc-starting plate 15a and the right arc-starting plate 15b may be adjusted accordingly, but it will affect the opening distance of the contact mechanism, thereby affecting the arc extinguishing efficiency and capability.

[0053] Furthermore, the arc-blocking plate 2 is in a transmission engagement with either the left contact 30 or the right contact 31. When the left contact 30 and the right contact 31 are closed, the arc-blocking plate 2 is driven by either the left contact 30 or the right contact 31 to move out of the contact points between the left contact 30 and the right contact 31. When the left contact 30 and the right contact 31 are open, the arc-blocking plate 2 is driven by either the left contact 30 or the right contact 31 to move into the contact points between the left contact 30 and the right contact 31. Furthermore, the arc-blocking plate 2 is in a transmission engagement with the right contact support of the right contact 31. Furthermore, the arc-blocking plate 2 includes a driven rack, and the right contact support includes a driving gear. The driven rack meshes with the driving gear, thereby driving the arc-blocking plate 2 to move while the right contact 31 swings. The arc-blocking plate 2 and the right contact support are mechanically connected to ensure the reliability of the arc-blocking plate 2's operation.

[0054] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. An arc-extinguishing device for a circuit breaker, comprising an arc-extinguishing chamber (14), the arc-extinguishing chamber (14) comprising a grid plate assembly, the grid plate assembly comprising multiple grid plates, each grid plate being arranged side-by-side along the length direction of the arc-extinguishing chamber (14); the arc-extinguishing chamber (14) comprising an arc inlet and an exhaust outlet located at both ends of the arc-extinguishing chamber (14) in the height direction of the arc-extinguishing chamber (14), the arc inlet being used to cooperate with the contact mechanism (3) of the circuit breaker; characterized in that: Along the length of the arc-extinguishing chamber (14), the arc-extinguishing chamber (14) is divided into two parts, namely the left part of the arc-extinguishing chamber and the right part of the arc-extinguishing chamber; The arc extinguishing device also includes a magnetizing device (1), which includes a permanent magnet group (12). The permanent magnet group (12) includes a left magnet group and a right magnet group. The magnetic field directions of the left magnet group and the right magnet group are opposite. In the width direction of the arc extinguishing chamber (14), the left magnet group is arranged side by side with the left side of the arc extinguishing chamber, and the right magnet group is arranged side by side with the right side of the arc extinguishing chamber. The contact mechanism includes a left contact (30) and a right contact (31). In the length direction of the arc-extinguishing chamber (14), the left contact (30) and the right contact (31) are arranged opposite each other, rotating synchronously towards each other to close and rotating synchronously away from each other to break.

2. The arc-extinguishing device for a circuit breaker according to claim 1, characterized in that: The left magnet group includes a left rear magnet (12a) and a left front magnet (12b), and the right magnet group includes a right rear magnet (12c) and a right front magnet (12d). In the width direction of the arc-extinguishing chamber (14), the left rear magnet (12a) and the left front magnet (12b) are located on the left side of the arc-extinguishing chamber, and the right rear magnet (12c) and the right front magnet (12d) are located on the right side of the arc-extinguishing chamber; the magnetic field direction between the left rear magnet (12a) and the left front magnet (12b) is opposite to the magnetic field direction between the right rear magnet (12c) and the right front magnet (12d).

3. The arc-extinguishing device for a circuit breaker according to claim 2, characterized in that: The arc-extinguishing chamber (14) is located entirely within the magnetic field of the permanent magnet assembly (12), and the permanent magnet assembly (12) is also used to cover the contacts of the contact mechanism (3).

4. The arc-extinguishing device for a circuit breaker according to claim 1, characterized in that: The magnetizing device (1) further includes an isolation plate group (11), which includes a rear isolation plate (11a) and a front isolation plate (11b). In the width direction of the arc-extinguishing chamber (14), the rear isolation plate (11a) and the front isolation plate (11b) are located on both sides of the arc-extinguishing chamber (14), and the isolation plate group (11) is arranged between the arc-extinguishing chamber (14) and the permanent magnet group (12).

5. The arc-extinguishing device for a circuit breaker according to claim 1, characterized in that: The arc extinguishing device also includes a left arc-inducing plate (15a) and a right arc-inducing plate (15b). In the length direction of the arc extinguishing chamber (14), the left arc-inducing plate (15a) and the right arc-inducing plate (15b) are located on both sides of the grid plate group and are arranged side by side with the grid plate group.

6. The arc-extinguishing device for a circuit breaker according to claim 5, characterized in that: In the height direction of the arc-extinguishing chamber (14), one end of the left arc-inducing plate (15a) and the right arc-inducing plate (15b) extends toward the exhaust port of the arc-extinguishing chamber (14) and is arranged side by side with the grid plate group. The other end of the left arc-inducing plate (15a) and the right arc-inducing plate (15b) extends away from the exhaust port of the arc-extinguishing chamber (14) respectively, protruding on one side of the arc-extinguishing chamber (14) to form a contact space for accommodating the contact point of the contact mechanism (3). The left arc-inducing plate (15a), the magnetizing device (1), and the right arc-inducing plate (15b) form a magnetic field space, and the contact point of the contact mechanism (3) and the arc-extinguishing chamber (14) are located in the magnetic field space.

7. The arc-extinguishing device for a circuit breaker according to claim 6, characterized in that: The magnetizing device (1) further includes a magnetic guide plate group (13), which includes a rear magnetic guide plate (13a) and a front magnetic guide plate (13b). In the width direction of the arc-extinguishing chamber (14), the rear magnetic guide plate (13a) and the front magnetic guide plate (13b) are located on both sides of the arc-extinguishing chamber (14).

8. The arc-extinguishing device for a circuit breaker according to claim 7, characterized in that: In the width direction of the arc-extinguishing chamber (14), the permanent magnet assembly (12) is disposed between the isolation plate assembly (11) and the magnetic guide plate assembly (13).

9. The arc-extinguishing device for a circuit breaker according to claim 7, characterized in that: The left arc-leading plate (15a), the rear magnetic guide plate (13a), the right arc-leading plate (15b), and the front magnetic guide plate (13b) are connected in sequence around the magnetic field space.

10. The arc-extinguishing device for a circuit breaker according to claim 1, characterized in that: The arc extinguishing device also includes an arc diaphragm plate (2), which is used to move between the contacts of the contact mechanism when the circuit breaker is tripped.

11. The arc-extinguishing device for a circuit breaker according to claim 1, characterized in that: The arc-extinguishing chamber (14) also includes mounting plates. In the width direction of the arc-extinguishing chamber (14), two mounting plates are arranged at intervals relative to each other, and each grid plate is located between the two mounting plates and is connected to the two mounting plates respectively.

12. A circuit breaker, characterized in that: The circuit breaker includes the arc-extinguishing device according to any one of claims 1-11.

13. The circuit breaker according to claim 12, characterized in that: The arc-extinguishing device has an arc-blocking plate (2) that is in transmission cooperation with the left contact (30) or the right contact (31). When the left contact (30) and the right contact (31) are closed, the arc-blocking plate (2) is driven by the left contact (30) or the right contact (31) to move out between the contact points of the left contact (30) and the right contact (31). When the left contact (30) and the right contact (31) are separated, the arc-blocking plate (2) is driven by the left contact (30) or the right contact (31) to move into the contact points of the left contact (30) and the right contact (31).

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