Arc quenching assembly and direct current circuit breaker

Abstract

The present disclosure relates to an arc extinguishing assembly and a direct current circuit breaker having the same. The arc extinguishing assembly comprises: a stationary contact comprising a stationary contact body; an arc chamber having a plurality of arc runner vanes arranged at intervals along a length direction thereof; a magnetic conducting assembly comprising a magnetic conducting member and a magnetic conducting member housing, the magnetic conducting member comprising a first magnetic conducting portion and a second magnetic conducting portion located at two sides of the stationary contact body, the first magnetic conducting portion and the second magnetic conducting portion each extending away from the stationary contact along the length direction of the arc chamber, the magnetic conducting member housing comprising a first housing accommodating portion and a second housing accommodating portion for accommodating the first magnetic conducting portion and the second magnetic conducting portion respectively; a magnetic body located between the first magnetic conducting portion and the second magnetic conducting portion; wherein the stationary contact body, the first housing accommodating portion, the second housing accommodating portion and the plurality of arc runner vanes of the arc chamber jointly define a confinement cavity.

Description

Technical Field

[0001] This disclosure relates to an arc-extinguishing assembly and a DC circuit breaker having said arc-extinguishing assembly. Background Technology

[0002] DC circuit breakers are an indispensable safety device in power systems and industrial automation. Their main function is to quickly interrupt current when abnormal conditions occur in the circuit, such as overload or short circuit, to avoid damage to the circuit and related equipment. One of the core components of a DC circuit breaker is its moving and stationary contacts. These contacts are in contact with each other to ensure the flow of current when the circuit is working normally, and they separate when it is necessary to interrupt the current.

[0003] During the separation of the moving and stationary contacts, an electric arc may be generated between the contacts due to the sudden interruption of current. This arc may damage the internal components of the DC circuit breaker. In situations requiring the interruption of small DC currents, such as those below 1000A, the arc may persist for an excessively long time or be difficult to extinguish.

[0004] We hope to find an effective arc-extinguishing scheme for DC circuit breakers, especially one that can effectively extinguish arcs under low DC current conditions. Utility Model Content

[0005] In response to the problems and needs mentioned above, this disclosure proposes an arc-extinguishing assembly for a DC circuit breaker and a DC circuit breaker having said arc-extinguishing assembly.

[0006] The arc-extinguishing assembly of the DC circuit breaker disclosed herein includes: a stationary contact, comprising a stationary contact body; an arc-extinguishing chamber having a plurality of arc-extinguishing grids spaced apart along its length; a magnetic conductive assembly, comprising a magnetic conductive element and a magnetic conductive element housing, the magnetic conductive element comprising a first magnetic conductive portion and a second magnetic conductive portion located on both sides of the stationary contact body, the first magnetic conductive portion and the second magnetic conductive portion both extending away from the stationary contact along the length of the arc-extinguishing chamber, the magnetic conductive element housing comprising a first housing receiving portion and a second housing receiving portion for accommodating the first magnetic conductive portion and the second magnetic conductive portion respectively; and a magnetic body located between the first magnetic conductive portion and the second magnetic conductive portion; wherein the stationary contact body, the first housing receiving portion, the second housing receiving portion, and the plurality of arc-extinguishing grids of the arc-extinguishing chamber together define a confining cavity.

[0007] According to the example scheme, the stationary contact body has a first section, a second section, and an intermediate section connecting the first section and the second section. The first section is closer to the moving contact that mates with the stationary contact than the second section. The first section, the second section, and the intermediate section form a U-shaped structure.

[0008] According to the example scheme, the stationary contact body has an integral structure.

[0009] According to the example scheme, the magnetic body is located inside the U-shaped structure of the stationary contact body.

[0010] According to the example scheme, it also includes an arc-inducing piece, one end of which is connected to a first section of the stationary contact body, and the other end extends to the end of the arc-extinguishing chamber near the stationary contact.

[0011] According to the example scheme, the magnetic conductive component further includes a connecting portion that connects the first magnetic conductive portion and the second magnetic conductive portion, so that the magnetic conductive component has a U-shaped structure.

[0012] According to the example scheme, the first magnetic conductive part, the second magnetic conductive part, and the connecting part of the magnetic conductive component are an integral structure.

[0013] According to the example scheme, the connecting part of the magnetic conductor is located between the first section and the second section of the stationary contact, and the U-shaped structure of the magnetic conductor surrounds the first section of the stationary contact.

[0014] According to the example scheme, the housing of the magnetic conductor is made of insulating material.

[0015] According to the example scheme, the magnetic conductive housing also includes a base plate connecting the first housing receiving portion and the second housing receiving portion.

[0016] According to the example scheme, the first segment of the arc-drawing plate and / or the stationary contact also participates in defining the limiting cavity.

[0017] According to the example scheme, the magnetic body is located on the surface of the connection portion of the magnetic conductor near the arc-extinguishing chamber.

[0018] According to the example scheme, the magnetic body is directly adsorbed onto the surface of the connection part of the magnetic conductor near the arc-extinguishing chamber.

[0019] According to the example scheme, the magnetic body is a permanent magnet.

[0020] According to the example scheme, it also includes a magnetic body housing surrounding the magnetic body, the magnetic body housing being made of an insulating material.

[0021] This disclosure also proposes a DC circuit breaker that includes an arc-extinguishing assembly as described in any of the preceding statements.

[0022] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings so that the features and advantages of the present disclosure can be readily understood. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit all embodiments of this disclosure to them.

[0024] Figure 1 An overall view of an example embodiment of the arc-extinguishing assembly proposed in this disclosure is shown;

[0025] Figure 2 An exploded view of some components of the arc-extinguishing assembly proposed in this disclosure is shown;

[0026] Figure 3A and 3B Example structures of the stationary contact body of the arc extinguishing assembly proposed in this disclosure are shown from different perspectives;

[0027] Figure 4A and 4B Exemplary assembly diagrams of the stationary contact, arc-starting plate, magnetic body, and magnetic conductor are shown from different perspectives;

[0028] Figure 5 An exemplary assembly view of the stationary contact and the arc-starting plate is shown;

[0029] Figure 6 An example structure of the magnetic conductive element of the arc-extinguishing assembly proposed in this disclosure is shown;

[0030] Figure 7 An example structure of the magnetic housing of the arc-extinguishing assembly proposed in this disclosure is shown;

[0031] Figure 8 An exemplary magnetic field that the arc-extinguishing assembly proposed in this disclosure can generate is shown;

[0032] Figure 9 An exemplary force diagram of an electric arc is shown;

[0033] Figure 10 The magnetic field distribution and arc force near the stationary contact are shown;

[0034] Figure 11 The magnetic field distribution and arc force are shown near the stationary contact in a pair of proportions.

[0035] Figure 12 and Figure 13 The confined cavity of this disclosure is shown from different perspectives.

[0036] List of reference numerals

[0037] 10 static contacts

[0038] 11 static contact silver point

[0039] 12 stationary contact body

[0040] 121 First Section

[0041] 122 Second Section

[0042] 123 Intermediate Section

[0043] 20 moving contacts

[0044] 30 arc-extinguishing chambers

[0045] 31 arc-quenching grid

[0046] 40 magnetic components

[0047] 41 First magnetic conductive section

[0048] 42 Second magnetic guide section

[0049] 43 Connecting parts

[0050] 50 magnetic bodies

[0051] 51 Magnetic housing

[0052] 60 arc-starting plate

[0053] 70 Magnetic housing

[0054] 71 First housing receiving section

[0055] 72 Second housing accommodating part

[0056] 73 base plate

[0057] 80 Restricted Cavity Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0059] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of this disclosure may have fewer components, other components not shown in the drawings, different components, components arranged differently, or components with different connections, etc. Furthermore, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0060] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “a” or “a” and similar terms do not necessarily indicate a quantity limitation. The terms “comprising” or “including” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0061] This disclosure relates to an arc-extinguishing assembly and a DC circuit breaker having said arc-extinguishing assembly.

[0062] The arc extinguishing components / solutions proposed in this disclosure are applicable to a variety of DC circuit breakers, and are particularly suitable for solving problems such as excessively long arcing time or failure to extinguish arcs when interrupting small currents at DC 1500V voltage. Here, "small current" can be, for example, 1000A and below, including currents of tens or hundreds of amps.

[0063] A DC circuit breaker includes a stationary contact 10 as its core component and a moving contact 20 that cooperates with the stationary contact 10. The moving contact 20 and the stationary contact 10 work together to control the opening and closing of the circuit. When opening or closing occurs, the stationary contact 10 remains stationary, while the moving contact 20 moves relative to the stationary contact 10. For example, the moving contact 20 can rotate about its own axis of rotation to engage or disengage from the stationary contact 10, thereby connecting or disconnecting the circuit. When the moving contact 20 separates from the stationary contact 10, an electric arc can easily be generated between them, and the arc may be difficult to extinguish, thereby damaging the contacts and other components of the DC circuit breaker.

[0064] This disclosure increases the magnetic field strength, improves the magnetic field distribution, and enhances the magnetic blowing force by structurally designing and overall arranging the magnetic body 50, magnetic conductive components, arc-extinguishing chamber 30, and stationary contact 10. This causes the electric arc to leave the silver point of the stationary contact 10 and move towards the arc-extinguishing chamber 30, thereby quickly extinguishing the electric arc.

[0065] The arc-extinguishing assembly of this disclosure is described below with reference to the accompanying drawings. Among them, Figure 1 An overall view of the exemplary arc-extinguishing assembly presented in this disclosure is shown. Figure 2 An exploded view of the arc-extinguishing assembly is shown, in which components such as the moving contact 20 and the arc-extinguishing chamber 30 are omitted.

[0066] like Figure 1 As shown, in the arc-extinguishing assembly of this disclosure, an arc-extinguishing chamber 30 is disposed near the stationary contact 10 and the moving contact 20 for extinguishing the electric arc generated between the stationary and moving contacts. The arc-extinguishing chamber 30 has a plurality of arc-extinguishing grids 31 spaced apart along the length L of the arc-extinguishing chamber 30. Each arc-extinguishing grid 31 may have the same or substantially the same size and shape. The plurality of arc-extinguishing grids 31 may be spaced apart from each other at uniform intervals. The arc-extinguishing chamber 30 has a front end near the arc-generating region between the moving contact 20 and the stationary contact 10 and a rear end opposite to the front end. After an arc is generated at the moving contact 20 and the stationary contact 10, the arc may enter the interior of the arc-extinguishing chamber 30 from the front end. The arc-extinguishing chamber 30 may also include a first insulating side plate and a second insulating side plate extending side-by-side between its front and rear ends, thereby holding the plurality of arc-extinguishing grids by the first and second insulating side plates.

[0067] like Figure 1 and Figure 2 As shown, the arc-extinguishing assembly includes a magnetic body 50 and a magnetically conductive assembly. The magnetic body 50 is capable of generating a magnetic field. Preferably, the magnetic body 50 is a permanent magnet. Alternatively, the magnetic body can be other magnetic structures capable of generating a magnetic field. The magnetically conductive assembly includes a magnetically conductive element 40 and a magnetically conductive element housing 70 that houses the magnetically conductive element 40. The magnetically conductive element 40 is used to change the distribution of magnetic field lines and change the local magnetic field strength. When the magnetic field acts on the arc, it can change the trajectory of charged particles in the arc, thereby guiding the arc. In this disclosure, the magnetic body 50 and the magnetically conductive element 40 are designed such that the magnetically conductive element 40 includes a first magnetically conductive portion 41 and a second magnetically conductive portion 42 located on both sides of the stationary contact body 12. Both the first magnetically conductive portion 41 and the second magnetically conductive portion 42 extend away from the stationary contact along the length direction L of the arc-extinguishing chamber 30, i.e., towards the moving contact 20. The magnetic body 50 is located between the first magnetically conductive portion 41 and the second magnetically conductive portion 42. The two magnetic conductive parts of the magnetic conductive element 40 extend along the length direction L of the arc-extinguishing chamber 30, which can better guide the magnetic field lines and make the magnetic field distribution more concentrated and stronger on the arc path.

[0068] The magnetic housing 70 is made of insulating material. Figure 7 An example structure of a magnetic component housing 70 is shown. The magnetic component housing 70 includes a first housing receiving portion 71 and a second housing receiving portion 72 for receiving a first magnetically conductive portion 41 and a second magnetically conductive portion 42, respectively. Preferably, the magnetic component housing 70 further includes a base plate 73 connecting the first housing receiving portion 71 and the second housing receiving portion 72, and the first housing receiving portion 71, the second housing receiving portion 72, and the base plate 73 are preferably integrally formed. The magnetic component housing 70 may include a plurality of housing components that together form a closed housing surrounding the magnetically conductive component 40. For example, Figure 1As shown, the magnetic housing 70 comprises two parts that together surround the magnetic element 40.

[0069] In this disclosure, the stationary contact, the arc-extinguishing chamber, and the magnetic conductive assembly are arranged such that the stationary contact body 12, the first housing accommodating portion 71, the second housing accommodating portion 72, and the plurality of arc-extinguishing grid plates 31 of the arc-extinguishing chamber 30 together define a confining cavity 80. Figure 12 and Figure 13 The confinement cavity of this disclosure is shown from different perspectives. The design of the confinement cavity 80 significantly increases the gas flow rate of currents of 36A and above entering the arc-extinguishing grid, shortening the response time of the gas-generating material and the low-temperature cold gas backfill, thereby improving arc-extinguishing performance.

[0070] Furthermore, the relative position and structural design of the magnetic body 50 and the magnetic conductor 40 in this disclosure allow for a more rational magnetic field distribution. Under the influence of the magnetic field, the trajectory of the charged particles in the arc is altered, effectively guiding them towards the arc-extinguishing chamber 30. Especially under low current conditions, the electromagnetic and air-blowing forces on the arc are relatively small, making it difficult to extinguish quickly. This design of the present disclosure, by enhancing the magnetic field strength and optimizing the magnetic field distribution, can effectively guide the arc into the arc-extinguishing chamber even under low current conditions, solving the problems of arcs failing to extinguish or having excessively long arcing times under low current conditions.

[0071] The specific structure of the first magnetically conductive portion 41 and the second magnetically conductive portion 42 of the magnetically conductive element 40 is not limited. Preferably, both have an elongated structure extending along the length direction of the arc-extinguishing chamber 30. This elongated structure should be able to cover part of the arc-extinguishing grid plate of the arc-extinguishing chamber 30, that is, the projection of part of the arc-extinguishing grid plate along its own length direction can fall on the first magnetically conductive portion or the second magnetically conductive portion. At the same time, a certain distance should be maintained between the arc-extinguishing grid plate and the magnetically conductive element 40 to prevent the magnetic lines of force from being weakened.

[0072] In some embodiments, the first magnetically conductive portion 41 and the second magnetically conductive portion 42 of the magnetically conductive member 40 are two separate components. In a preferred embodiment, such as Figure 6 As shown, the magnetic conductive component 40 also includes a connecting portion 43 that connects the first magnetic conductive portion 41 and the second magnetic conductive portion 42, so that the magnetic conductive component 40 has a U-shaped structure.

[0073] Designing the magnetic conductor 40 as a U-shaped structure facilitates its installation. For example, as described below, the U-shaped structure of the magnetic conductor 40 can be installed around a portion of the stationary contact 10, thus enabling the formation of a firmly assembled modular assembly. Furthermore, the presence of the connecting portion 43 prevents air gaps between individual magnetic conductors 40, thereby enhancing the magnetic field strength.

[0074] Preferably, the first magnetic conductive part 41, the second magnetic conductive part 42, and the connecting part 43 of the magnetic conductive component 40 are an integral structure, thereby reducing the number of parts, manufacturing costs, and assembly complexity.

[0075] Still refer to Figure 1 and Figure 2 The arc-extinguishing assembly also includes an arc-initiating plate 60. The arc-initiating plate 60 has a curved, sheet-like structure and is preferably made of iron or other metals with good electrical conductivity. Its surface may be treated to improve conductivity and high-temperature resistance. One end of the arc-initiating plate 60 engages with the stationary contact 10, and the other end extends into the arc-extinguishing chamber 30. When the DC circuit breaker trips, the arc-initiating plate 60 facilitates the smooth entry of the arc into the arc-extinguishing chamber 30.

[0076] This disclosure also includes a design for the structure of the stationary contact 10 to facilitate arc blowing. Figure 3A and 3B Example structures of the stationary contact body 12 of the arc-extinguishing assembly proposed in this disclosure are shown from different perspectives. For example... Figure 3A and 3B As shown, the stationary contact 10 may include a stationary contact body 12 and a stationary contact silver dot 11 disposed on the stationary contact body 12.

[0077] The stationary contact silver point 11 can be a thin silver coating or a separate silver contact point, used to reduce contact resistance, improve conductivity, and provide good wear and corrosion resistance. The main surface of the stationary contact silver point 11 faces the moving contact.

[0078] The stationary contact body 12 preferably has a first segment 121, a second segment 122, and an intermediate segment 123 connecting the first segment 121 and the second segment 122, wherein the first segment 121 is closer to the moving contact than the second segment 122. Preferably, as follows... Figure 3B As shown, the first section 121, the second section 122, and the intermediate section 123 form a U-shaped structure. The stationary contact silver dot 11 can be located at the bottom of the first section 121, or at the end of the intermediate section 123 near the moving contact, or at the transition position between the first section and the intermediate section.

[0079] Preferably, the portion of the stationary contact body 12 that defines the limiting cavity 80 is the first section 121 of the stationary contact body 12. That is, the first housing receiving portion 71, the second housing receiving portion 72, the arc-extinguishing grid 31 of the arc-extinguishing chamber 30, and the first section 121 of the stationary contact together define the limiting cavity 80. Furthermore, preferably, as... Figure 12 and 13 As shown, the arc-inducing plate 60 mentioned above also participates in defining the limiting cavity 80.

[0080] Figure 10The diagram illustrates the magnetic field distribution and arc forces near the stationary contact. The dashed line I represents the current direction. Due to the U-shaped structure of the stationary contact, the current also forms a U-shaped flow path, specifically creating segment A. This current generates a self-excited magnetic field, in which the arc experiences an upward magnetic force, favoring its transfer towards the arc-extinguishing chamber. In a pair of proportions, such as... Figure 11 As shown, the stationary contact does not have a U-shaped structure and cannot generate the aforementioned segment A current, thus it cannot generate a magnetic blowing force on the arc through a self-excited magnetic field as in this solution.

[0081] When the stationary contact body and the magnetic conductor are in contact, the electric arc is subjected to an even greater magnetic blow-out force. This will be discussed in detail below. Figure 8 and Figure 9 Let me introduce it.

[0082] Preferably, the stationary contact body 12 has an integral structure, thereby reducing the number of parts, manufacturing costs, and assembly complexity.

[0083] One end of the arc-inducing piece 60 is preferably connected to the first section 121 of the stationary contact body 12. For example, a notch 1211 matching the end shape of the arc-inducing piece 60 can be designed at the top of the first section 121, thereby increasing the contact area between the first section 121 of the stationary contact 10 and the arc-inducing piece 60 and enhancing their connection strength. Figure 5 An exemplary assembly view of the stationary contact 10 and the arc-starting piece 60 is shown, showing that one end of the arc-starting piece 60 is engaged in the notch 1211 of the first segment 121 of the stationary contact 10.

[0084] Preferably, the magnetic body 50 is located inside the U-shaped structure of the stationary contact body 12. This design not only saves space and facilitates the compact assembly of the overall components, but also makes the distribution of the magnetic field conducive to the magnetic blowing of the electric arc.

[0085] Figure 4A and 4BExemplary assembly diagrams of the stationary contact 10, arc-inducing plate 60, magnetic body 50, and magnetic conductor 40 are shown from different perspectives. It can be seen that by designing both the stationary contact body 12 and the magnetic conductor 40 with U-shaped structures, they can form a modular assembly that is firmly assembled together. Furthermore, the magnetic body 50 can be placed within the U-shaped structure of the stationary contact body 12 and simultaneously within the U-shaped structure of the magnetic conductor 40, thereby achieving optimal magnetic field line distribution and magnetic blowing effect. The assembly formed by the stationary contact 10, magnetic body 50, and magnetic conductor 40 also has a compact modular structure. As shown in the figure, in the illustrated direction, the connecting portion 43 is located above the middle section 123 of the stationary contact 10. The connecting portion 43 of the magnetic conductor 40 is located between the first section 121 and the second section 122 of the stationary contact 10, and the U-shaped structure of the magnetic conductor 40 surrounds the first section 121 of the stationary contact 10, thereby forming a tight connection.

[0086] In principle, the magnetic body 50 can be positioned close to the magnetic conductor 40. However, preferably, the magnetic body 50 is located on the surface of the connecting portion 43 of the magnetic conductor 40 near the arc-extinguishing chamber 30. In particular, the magnetic body 50 is directly adsorbed onto the surface of the connecting portion 43 of the magnetic conductor 40 near the arc-extinguishing chamber 30. This facilitates the installation of the magnetic body 50 and fully utilizes the guiding effect of the magnetic conductor 40 on the magnetic field. In other embodiments, the magnetic body 50 can be fixed or bonded to the magnetic conductor 40 by other means.

[0087] Through the structural and relative positional design of the magnetic body 50, the magnetic conductor 40, and the stationary contact 10, such as Figure 8 and 9 As shown, the magnetic field distribution generated by this arc-extinguishing component can maximize the promotion of arc transfer, thereby enhancing the arc-extinguishing effect. Figure 8 As shown, the presence of the magnetic conductive element redistributes the magnetic field of the magnetic body. The magnetic field direction starts from the N pole and returns to the S pole, and there are horizontal and vertical magnetic field components in the coverage area of ​​the first magnetic conductive part 41 and the second magnetic conductive part 42. Figure 9 The arc is shown by a thick, curved black line, and the forces acting on the arc are illustrated by circles A and B, representing two different current flow directions. Circle A shows the current flowing from right to left along the plane of the paper, while circle B shows the current flowing from left to right. When the current flows from left to right, initially, as the moving and stationary contacts separate, the arc is located within the area covered by the first magnetically conductive part 41 and the second magnetically conductive part 42, and is acted upon by the vertical component of the magnetic field. According to the left-hand rule, the arc experiences a force in the direction of Fx, causing it to transfer to the first magnetically conductive part 41. After the arc transfers to the first magnetically conductive part 41, it is acted upon by the horizontal component of the magnetic field on that side. According to the left-hand rule, the magnetic force acting on the arc at this point is FZ, causing the arc to move upwards into the arc-extinguishing chamber.

[0088] Conversely, when the current direction is from right to left (i.e., Figure 9 As shown in circle A, in the initial stage of arc generation, under the action of the vertical magnetic field component, the arc is transferred to the second magnetic conductive part 42 to the right due to the magnetic force in the Fx direction. Subsequently, the arc is affected by the horizontal component of the magnetic field on this side, causing the arc to bear the magnetic force in the Fz direction, so the arc enters the arc extinguishing chamber upward.

[0089] Therefore, it can be seen that for the arc extinguishing system disclosed herein, regardless of the direction of the current, the arc can be reliably transferred into the arc extinguishing chamber.

[0090] The arc extinguishing assembly may also include a magnetic body housing 51 surrounding the magnetic body 50, the magnetic body housing 51 being made of an insulating material.

[0091] In this disclosure, the combined design of the stationary contact, magnetic body, and magnetic conductor significantly improves arc-extinguishing performance and the overall reliability of the DC circuit breaker. The U-shaped structure of the stationary contact closely matches the U-shaped structure of the magnetic conductor, enhancing the magnetic field strength and optimizing the magnetic field distribution. This allows the arc to be guided more effectively to the arc-extinguishing chamber, thereby shortening the arcing time and reducing contact erosion. The magnetic body is placed inside the U-shaped structure of the stationary contact and located on top of the magnetic conductor, further strengthening the magnetic field effect, improving arc-extinguishing efficiency, and forming a compact modular design. This reduces manufacturing costs and assembly complexity, while improving the arc-extinguishing performance and service life of the DC circuit breaker. It is particularly suitable for low-current breaking scenarios and effectively solves the problem of arc extinguishing.

[0092] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.

Claims

1. An arc-extinguishing assembly for a DC circuit breaker, characterized in that, include: The stationary contact (10) includes the stationary contact body (12); The arc-extinguishing chamber (30) has a plurality of arc-extinguishing grids (31) arranged at intervals along its length direction (L). The magnetic conductive assembly includes a magnetic conductive element (40) and a magnetic conductive element housing (70). The magnetic conductive element (40) includes a first magnetic conductive portion (41) and a second magnetic conductive portion (42) located on both sides of the stationary contact body (12). The first magnetic conductive portion (41) and the second magnetic conductive portion (42) both extend away from the stationary contact (10) along the length direction (L) of the arc-extinguishing chamber (30). The magnetic conductive element housing (70) includes a first housing receiving portion (71) and a second housing receiving portion (72) for accommodating the first magnetic conductive portion (41) and the second magnetic conductive portion (42), respectively. A magnetic body (50) is located between the first magnetic conductive part (41) and the second magnetic conductive part (42); The stationary contact body (12), the first housing accommodating portion (71), the second housing accommodating portion (72), and the plurality of arc-extinguishing grids (31) of the arc-extinguishing chamber (30) together define a confining cavity (80).

2. The arc-extinguishing assembly as described in claim 1, characterized in that, The stationary contact body (12) has a first section (121), a second section (122) and an intermediate section (123) connecting the first section (121) and the second section (122). The first section (121) is closer to the moving contact that cooperates with the stationary contact than the second section (122). The first section (121), the second section (122) and the intermediate section (123) form a U-shaped structure.

3. The arc-extinguishing component as described in claim 2, characterized in that, The stationary contact body (12) has an integral structure.

4. The arc-extinguishing assembly as described in claim 2, characterized in that, The magnetic body (50) is located inside the U-shaped structure of the stationary contact body (12).

5. The arc-extinguishing assembly as described in claim 2, characterized in that, It also includes an arc-starting piece (60), one end of which is connected to the first section (121) of the stationary contact body (12) and the other end extends to the end of the arc-extinguishing chamber (30) near the stationary contact (10).

6. The arc-extinguishing assembly as described in claim 2, characterized in that, The magnetic conductive component (40) further includes a connecting portion (43) that connects the first magnetic conductive part (41) and the second magnetic conductive part (42), so that the magnetic conductive component (40) has a U-shaped structure.

7. The arc-extinguishing assembly as described in claim 6, characterized in that, The first magnetic part (41), the second magnetic part (42), and the connecting part (43) of the magnetic conductive component (40) are an integral structure.

8. The arc-extinguishing assembly as described in claim 6, characterized in that, The connecting portion (43) of the magnetic conductor (40) is located between the first section (121) and the second section (122) of the stationary contact (10), and the U-shaped structure of the magnetic conductor (40) surrounds the first section (121) of the stationary contact (10).

9. The arc-extinguishing assembly as described in claim 5, characterized in that, The housing (70) of the magnetic conductor is made of insulating material.

10. The arc-extinguishing assembly as described in claim 5, characterized in that, The magnetic housing (70) also includes a base plate (73) connecting the first housing receiving part (71) and the second housing receiving part (72).

11. The arc-extinguishing assembly as described in claim 5, characterized in that, The arc-starting plate (60) and / or the first section (121) of the stationary contact also participate in defining the limiting cavity (80).

12. The arc-extinguishing assembly as described in claim 6, characterized in that, The magnetic body (50) is located on the surface of the connecting part (43) of the magnetic conductor (40) near the arc-extinguishing chamber (30).

13. The arc-extinguishing assembly as described in claim 12, characterized in that, The magnetic body (50) is directly adsorbed on the surface of the connection part (43) of the magnetic conductor (40) near the arc-extinguishing chamber (30).

14. The arc-extinguishing assembly as described in claim 1, characterized in that, The magnetic body (50) is a permanent magnet.

15. The arc-extinguishing assembly as described in claim 1, characterized in that, It also includes a magnetic body housing (51) surrounding the magnetic body (50), the magnetic body housing (51) being made of an insulating material.

16. A DC circuit breaker, characterized in that, Includes the arc-extinguishing component as described in any one of claims 1 to 15.

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