Arc extinguishing structure for DC air circuit breaker

Abstract

According to one embodiment of the present invention, an arc extinguishing portion structure for a DC air circuit breaker includes: a plurality of grid components; side plates, which are combined to both sides of the plurality of grid components so that the plurality of grid components are stacked in a separated state; an exhaust hood, which is located above the side plates and the plurality of grid components; an arc guide, which is combined with the side plates to be located at the bottom of the plurality of grid components; and a magnet, which is combined with the arc guide, and the magnet is magnetized to have different poles from each other based on the upper and lower arrangement directions of the plurality of grid components and the arc guide.

Description

Technical Field

[0001] The invention relates to an arc extinguishing part structure for a DC air circuit breaker. Background Art

[0002] Generally, an air circuit breaker (ACB) is an electrical device installed in a low-voltage distribution line and uses air as an arc extinguishing medium. It not only performs the transmission / reception, switching and stopping of power in the low-voltage distribution network in a planned manner, but also protects human life and load equipment by breaking the circuit when abnormal currents such as overcurrent, short circuit and ground fault occur.

[0003] More specifically, the DC air circuit breaker according to the prior art includes an arc extinguishing part and a power supply part inside the circuit breaker. When an abnormal current is generated due to overcurrent, short circuit, ground fault, etc. of the line, the mechanical part of the product is activated by the relay, so that the fixed contact and the movable contact are separated.

[0004] In addition, an arc is generated when the fixed contact and the movable contact are separated. Therefore, the generated arc moves from the fixed contact and the movable contact to the cooling plate under the action of the Lorentz force (arc magnetic field driving force) generated orthogonally due to the arc current and the magnetic flux density, and is cooled and extinguished.

[0005] Furthermore, the arc guide is combined with the arc chamber assembly, and the arc guide is used to guide the arc to the center of the cooling plate, so as to quickly extinguish the arc.

[0006] However, when breaking small currents according to the IEC 60947-3 ANNEX D standard, the arc generates very little magnetic field driving force due to the small current and magnetic field. In addition, the arc stagnates between the fixed contact and the movable contact.

[0007] In addition, the high-temperature arc stagnation phenomenon will cause serious damage to the structure and electrical properties of the arc extinguishing part and the energizing part, and lead to product performance degradation and equipment accidents. Summary of the invention

[0008] Problem that the invention aims to solve

[0009] One aspect of the present invention is to provide an arc extinguishing portion structure for a DC air circuit breaker, which generates an arc magnetic field driving force through a magnetic field of a magnet, thereby enabling the arc to be quickly discharged to the arc extinguishing portion.

[0010] Another aspect of the present invention is to provide an arc extinguishing structure for a DC air circuit breaker, wherein in an arc chamber assembly, a magnet is magnetized to have different poles in the upper and lower directions of an arc guide under a grid member, thereby preventing arc reverse flow.

[0011] Another aspect of the present invention is to provide an arc extinguishing portion structure for a DC air circuit breaker, which can maximize arc magnetic field driving force by maximizing the magnetic field magnitude of a magnet inserted into an arc guide.

[0012] Another aspect of the present invention is to provide an arc extinguishing structure for a DC air circuit breaker, which can shorten the arc duration while ensuring a small current breaking performance.

[0013] Means used to solve problems

[0014] According to one embodiment of the present invention, an arc extinguishing portion structure for a DC air circuit breaker includes: a plurality of grid components; side plates, which are combined to both sides of the plurality of grid components so that the plurality of grid components are stacked in a separated state; an exhaust hood, which is located above the side plates and the plurality of grid components; an arc guide, which is combined with the side plates to be located at the bottom of the plurality of grid components; and a magnet, which is combined with the arc guide, and the magnet is magnetized to have different poles from each other based on the upper and lower arrangement directions of the plurality of grid components and the arc guide.

[0015] In addition, in the arc extinguishing part structure for a DC air circuit breaker, a magnet insertion groove for accommodating the magnet may be formed in the arc guide, the magnet may extend along the stacking direction of the grid component, and the magnet insertion groove may extend along the stacking direction of the grid component.

[0016] Furthermore, in the arc extinguishing portion structure for a DC air circuit breaker, a side plate fixing portion may be formed in the magnet insertion slot, and an arc guide fixing portion corresponding to the side plate fixing portion may be formed in the side plate.

[0017] Furthermore, in the arc extinguishing portion structure for a DC air circuit breaker, the side plate fixing portion and the arc guide fixing portion may be formed as through holes.

[0018] In addition, in the arc extinguishing part structure for a DC air circuit breaker, the magnet is formed to extend along the length direction of the arc guide and is formed with a mounting hole corresponding to the through hole. It also includes a fixing component for combining the arc guide fixing part, the mounting hole and the side plate fixing part. When the magnet is placed in the magnet insertion slot with the aid of the fixing component, the arc guide is fixed to the side plate.

[0019] Furthermore, in the arc extinguishing portion structure for a DC air circuit breaker, the upper portion of the magnet may be magnetized to an S pole, and the lower portion may be magnetized to an N pole.

[0020] In addition, in the arc extinguishing portion structure for a DC air circuit breaker, the plate portion of the arc guide formed with a magnet insertion slot can be formed with a width on one side greater than the width on the other side, the magnet insertion slot can be formed with a width on one side greater than the width on the other side, and the width of one side of the magnet coupled to the magnet insertion slot can be greater than the width on the other side.

[0021] In addition, in the arc extinguishing part structure for a DC air circuit breaker, there are a plurality of magnets, a plurality of magnet insertion slots for accommodating the magnets and a side plate fixing part formed in the magnet insertion slots are formed in the arc guide, and an arc guide fixing part corresponding to the side plate fixing part is formed on the side plate.

[0022] Furthermore, in the arc extinguishing portion structure for a DC air circuit breaker, the side plate fixing portion and the arc guide fixing portion may be formed as through holes.

[0023] Furthermore, in the arc extinguishing structure for a DC air circuit breaker,

[0024] A fixing member for combining the arc guide fixing portion and the side plate fixing portion may be further included, and the arc guide may be fixed to the side plate in a state where the magnet is seated in the magnet insertion groove by means of the fixing member.

[0025] Furthermore, in the arc extinguishing portion structure for a DC air circuit breaker, the upper portion of the magnet may be magnetized to an S pole, and the lower portion may be magnetized to an N pole.

[0026] In addition, in an arc extinguishing structure for a DC air circuit breaker, the arc guide is formed to extend from one side to the other side and downward from one side in a length direction, and the magnet insertion slot is formed with a first magnet insertion slot extending downward from one side of the arc guide and a second magnet insertion slot extending from one side to the other side of the arc guide, and the magnet includes a first magnet formed to extend downward to correspond to the first magnet insertion slot (2410a) and a second magnet formed to extend in a length direction to correspond to the second magnet insertion slot.

[0027] In addition, in the arc extinguishing structure for a DC air circuit breaker, a downward inclined portion may be formed in the grid component so that the lower portion of the grid component extends from the center portion to both ends, and a guide plate portion may also be formed in the arc guide, which is formed as an upward inclined portion corresponding to the downward inclined portion.

[0028] Effects of the Invention

[0029] According to the present invention, an arc extinguishing part structure for a DC air circuit breaker can be obtained, which has the following effects: an arc magnetic field driving force is generated by the magnetic field of a magnet, and the arc can be quickly discharged to the arc extinguishing part by the arc magnetic field driving force. According to another aspect of the present invention, in the arc chamber assembly, the magnet can be magnetized to have different poles in the upper and lower directions of the arc guide located at the lower part of the grid member, thereby preventing arc backflow. The arc magnetic field driving force can be maximized by maximizing the magnetic field size of the magnet inserted into the arc guide, and the small current breaking performance can be ensured while shortening the arc duration. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. 1 is a diagram schematically showing a configuration of an arc extinguishing portion structure for a DC air circuit breaker according to a first embodiment of the present invention.

[0031] Figure 2 It is schematically shown Figure 1 The structure diagram of the arc guide in the arc extinguishing portion structure shown.

[0032] Figure 3 It is schematically shown Figure 1 The structural diagram of the magnet in the arc extinguishing part structure is shown.

[0033] Figure 4 FIG. 1 is a diagram schematically showing a configuration of an arc extinguishing portion structure for a DC air circuit breaker according to a second embodiment of the present invention.

[0034] Figure 5 It is schematically shown Figure 4 The structure diagram of the arc guide in the arc extinguishing portion structure shown.

[0035] Figure 6 It is schematically shown Figure 4 The structural diagram of the magnet in the arc extinguishing part structure is shown.

[0036] Figure 7 FIG. 1 is a diagram schematically showing a structure of a DC air circuit breaker equipped with an arc extinguishing portion structure according to the present invention.

[0037] Figure 8 yes Figure 7 FIG. 1 is a schematic diagram of a first usage state of the arc extinguishing portion structure of the first embodiment in a DC air circuit breaker.

[0038] Fig. 9 yes Figure 7 FIG. 1 is a schematic diagram of a second use state of the arc extinguishing structure of the first embodiment in a DC air circuit breaker.

[0039] Fig.10 yes Figure 7FIG. 1 is a schematic diagram of a first use state of an arc extinguishing portion structure according to a second embodiment in a DC air circuit breaker.

[0040] Fig.11 yes Figure 7 FIG. 1 is a schematic diagram of a second use state of the arc extinguishing portion structure according to the second embodiment in a DC air circuit breaker. DETAILED DESCRIPTION

[0041] Figure 1 Schematically shows a structural diagram of an arc extinguishing portion structure for a DC air circuit breaker according to a first embodiment of the present invention, Figure 2 It is schematically shown Figure 1 The structural diagram of the arc guide in the arc extinguishing part structure shown in FIG. Figure 3 It is schematically shown Figure 1 The structural diagram of the magnet in the arc extinguishing part structure is shown.

[0042] In a DC air circuit breaker used in various devices requiring DC interruption including a solar power generation facility, the arc extinguishing portion structure 1000 is used to ensure a small current interruption performance.

[0043] As shown in the figure, the arc extinguishing unit structure 1000 includes a side plate 1100 , a grid member 1200 , an exhaust cover 1300 , an arc guide 1400 , and a magnet 1500 .

[0044] More specifically, the grid member 1200 is a cooling plate for dividing and cooling the introduced arc, and a plurality of grid members 1200 are stacked between the side plates 1100 located at both sides with respect to the exhaust hood 1300 in a state of being spaced apart from each other.

[0045] To this end, fixing protrusions 1210 are formed at both ends of the grid member 1200 , and through holes 1110 corresponding to the fixing protrusions 1210 are formed in the side plate 1100 .

[0046] A downwardly inclined portion 1220 is formed in the grid member 1200 such that the lower portion of the grid member 1200 extends from the center portion to both end portions.

[0047] The exhaust cover 1300 is coupled to an upper portion of the side plate 1100 , and the arc guide 1400 is coupled to a lower portion of the side plate 1100 .

[0048] To this end, an arc guide fixing portion 1120 and an exhaust hood coupling portion 1130 are formed in the side plate 1100 .

[0049] The exhaust hood 1300 is located above the side plate 1100 and the plurality of grill members. The exhaust hood 1300 has a side plate coupling portion 1310 formed therein corresponding to the exhaust hood coupling portion 1130 of the side plate.

[0050] And, as one embodiment of the above, Figure 1 A case where the side plate coupling portion 1310 is formed as a protrusion and the exhaust hood coupling portion 1130 is formed as a through portion is shown.

[0051] The arc guide 1400 is fixed to the side plate to be located at a lower portion of the plurality of grid members 1200 .

[0052] In addition, the arc guide 1400 is formed with a magnet insertion groove 1410, a guide plate portion 1420, and a side plate fixing portion 1430. The magnet insertion groove 1410 has a shape corresponding to the magnet 1500.

[0053] In addition, the magnet insertion groove 1410 extends in the stacking direction of the grid member 1200 , and the guide plate portion 1420 extends to face the grid member 1200 .

[0054] The side plate fixing part 1430 may be formed in the magnet insertion groove 1410 .

[0055] The guide plate portion 1420 may be formed as an upwardly inclined portion corresponding to the downwardly inclined portion 1220 of the grid member 1200 .

[0056] The side plate fixing portion 1430 is used to fix the arc guide 1400 to the side plate 1100, and corresponds to the arc guide fixing portion 1120. In addition, the arc guide fixing portion 1120 and the side plate fixing portion 1430 may be formed as through holes.

[0057] Magnet 1500 is formed to extend in the length direction of arc guide 1400, that is, the stacking direction of grid members, and is magnetized to have different magnetic poles in the upper and lower directions orthogonal to the extending direction, that is, the arrangement direction of grid members 1200 and arc guide 1400.

[0058] As an example of this situation, Figure 3 In the embodiment, the upper first pole 1500a is magnetized to an S pole, and the lower second pole 1500b is magnetized to an N pole.

[0059] As described above, as the magnet is magnetized and coupled to the arc guide 1400, the magnetic field driving force is maximized, so that rapid cooling and arc extinguishing of the arc can be achieved.

[0060] In addition, a mounting hole 1510 is formed in the magnet 1500. The mounting hole 1510 is formed to correspond to the side plate fixing portion and the arc guide fixing portion formed in the form of a through hole.

[0061] In addition, the plate portion of the arc guide 1400 where the magnet insertion groove 1410 is formed may be formed to have a width greater on one side than on the other side. This is a result of considering the overall structure of the arc extinguishing portion structure 1000 installed in the circuit breaker.

[0062] In addition, the magnet insertion groove 1410 is formed to have a width greater than the other side corresponding to the above structure. The magnet 1500 coupled to the magnet insertion groove 1410 is also formed to have a width greater than the other side.

[0063] The arc extinguishing unit structure 1000 further includes a fixing member 1600 for combining the arc guide fixing portion 1120, the mounting hole 1510, and the side plate fixing portion 1430. Thus, the arc guide can be fixed to the side plate in a state where the magnet is combined with the arc guide.

[0064] In addition, an insulating layer 1610 of silicon or the like may be formed on the outer periphery of the fixing member 1600 .

[0065] Figure 4 Schematically shows a structural diagram of an arc extinguishing portion structure for a DC air circuit breaker according to a second embodiment of the present invention, Figure 5 It is schematically shown Figure 4 The structural diagram of the arc guide in the arc extinguishing part structure shown in FIG. Figure 6 It is schematically shown Figure 4 The structural diagram of the magnet in the arc extinguishing part structure is shown.

[0066] As shown in the figure, the arc extinguishing structure 2000 is Figures 1 to 3 The arc extinguishing portion structure 1000 shown is different only in the magnet and the magnet insertion groove 1410 for accommodating the magnet.

[0067] More specifically, the arc extinguishing portion structure 2000 includes a side plate 2100, a grid member 2200, an exhaust cover 2300, an arc guide 2400, and magnets 2500a and 2500b.

[0068] The magnets include a first magnet 2500a and a second magnet 2500b.

[0069] Also, the side plate 2100 , the grid member 2200 , and the exhaust hood 2300 are the same as the side plate 1100 , the grid member 2200 , and the exhaust hood 2300 of the arc extinguishing portion structure 1000 according to the first embodiment, and thus the same detailed description as above will be omitted.

[0070] The arc guide 2400 is formed with a magnet insertion slot 2410, a guide plate portion 2420, and a side plate fixing portion 2430. The magnet insertion slot 2410 is formed with a first magnet insertion slot 2410a into which the first magnet 2500a is inserted and coupled, and a second magnet insertion slot 2410b into which the second magnet 2500b is inserted and coupled.

[0071] In addition, the first magnet insertion groove 2410 a and the second magnet insertion groove 2410 b are formed in a region where the side plate fixing portion 2430 is not formed.

[0072] The arc guide 2400 is formed to extend from one side to the other side in the length direction and to extend downward from one side. Therefore, the arc guide 2400 is formed with a first magnet insertion slot 2410a extending downward from one side and a second magnet insertion slot 2410b extending from one side to the other side.

[0073] The first magnet 2500a is formed to extend downward to correspond to the first magnet insertion groove 2410, and the second magnet 2500b is formed to extend in the length direction to correspond to the second magnet insertion groove 2410b.

[0074] The first magnet 2500a and the second magnet 2500b are magnetized to have different magnetic poles in the upper and lower directions based on a direction perpendicular to the extending direction of the arc guide 2400, that is, an arrangement direction of the grid member 2200 and the arc guide 2400.

[0075] As an example, in Figure 6 In the embodiment, the upper first poles 2500a' and 2500b' are magnetized to S poles, and the lower second poles 2500a", and 2500b" are magnetized to N poles.

[0076] Furthermore, the first magnet 2500a is inserted into the first magnet insertion groove 2410a, the second magnet 2500b is inserted into the second magnet insertion groove 2410b, and in this state, the fixing member 2600 is combined with the arc guide fixing part 2120 and the side plate fixing part 2430, thereby fixing the arc guide 2400 to the side plate 2100.

[0077] Figure 7 FIG. 1 is a diagram schematically showing a structure of a DC air circuit breaker equipped with an arc extinguishing portion structure according to the present invention.

[0078] As shown in the figure, the arc extinguishing portion structures 1000 and 2000, the fixed conductor assembly 3000 and the movable conductor assembly 4000 are mounted to the main body of the DC air circuit breaker.

[0079] Furthermore, the movable conductor assembly 4000 is installed to face the fixed conductor assembly 3000 , and the arc extinguishing portion structures 1000 , 2000 are located above the fixed conductor assembly 3000 and the movable conductor assembly 4000 to extinguish arcs generated when the contacts are separated.

[0080] Figure 8 yes Figure 7 A schematic diagram of a first use state of the arc extinguishing structure of the first embodiment of the DC air circuit breaker shown in FIG. Fig. 9 yes Figure 7 FIG. 1 is a schematic diagram of a second use state of the arc extinguishing structure of the first embodiment in a DC air circuit breaker.

[0081] like Figure 8 As shown, when the magnet 1500 is mounted on the arc guide 1400, as shown by the arrows, a magnetic field is distributed when a small current is interrupted.

[0082] In addition, in the case of breaking a small current in a DC air circuit breaker, the magnetic field around the magnet is evenly distributed.

[0083] And, if Fig. 9 As shown, the magnitude of the arc magnetic field driving force is determined by the magnetic field size of the magnet, while its direction is orthogonal to the direction of the magnetic field and current.

[0084] That is, based on the magnetic field distribution and the connection direction of the small current, the arc magnetic field driving force F acts on the grid member 1200 as shown by the arrow. Fig. 9 (a) shows the driving force F when the current direction is drawn in the extending direction of the arc guide 1400, Fig. 9 (b) shows the driving force F when the current direction is drawn in the extending direction of the arc guide 1400 .

[0085] As a result, based on the magnetic field distribution and the connection direction of the small current, when the small current is disconnected, the arc magnetic field driving force acts in the side direction of the gate member 1200, and as described above, due to the formation of the arc magnetic field driving force F, not only can the arc be extinguished quickly, but arc backflow will not occur, and arc stagnation will not occur.

[0086] Fig.10 yes Figure 7 A schematic diagram of a first use state of the arc extinguishing structure of the second embodiment of the DC air circuit breaker shown in FIG. Fig.11 yes Figure 7 FIG. 1 is a schematic diagram of a second usage state of the arc extinguishing structure of the second embodiment in a DC air circuit breaker.

[0087] like Fig.10As shown, when the magnet 2500 is mounted on the arc guide 2400, as shown by the arrows, a magnetic field is distributed when a small current is interrupted.

[0088] In addition, in the case of breaking a small current in a DC air circuit breaker, the magnetic field around the magnet is evenly distributed.

[0089] like Fig.11 As shown, the magnitude of the arc magnetic field driving force is determined by the magnetic field of the magnet, while its direction is orthogonal to the magnetic field and current directions.

[0090] That is, based on the magnetic field distribution and the connection direction of the small current, the arc magnetic field driving force F acts on the grid member 2200 as shown by the arrow. Fig.11 (a) shows the driving force F when the direction of the current is drawn in the extending direction of the arc guide 2400, Fig.11 (b) shows the driving force F when the reverse direction of the current is introduced in the extending direction of the arc guide 2400 .

[0091] As a result, based on the magnetic field distribution and the connection direction of the small current, when the small current is disconnected, the arc magnetic field driving force acts in the side direction of the gate member 1200, and as described above, due to the formation of the arc magnetic field driving force F, not only can the arc be extinguished quickly, but arc backflow will not occur, and arc stagnation will not occur.

[0092] As described above, the arc extinguishing portion structure 1000 according to the first embodiment of the present invention and the arc extinguishing portion structure 2000 according to the second embodiment can both quickly extinguish the arc without arc backflow and arc stagnation. At the same time, the arc extinguishing portion structure 1000 ensures the maximum size of the magnet, thereby maximizing the arc magnetic field driving force, and the arc extinguishing portion structure 2000 makes the magnet easy to install regardless of the side plate fixing portion 2430, thereby improving assemblability and productivity.

[0093] Although the preferred embodiments of the present invention are described above with reference to the accompanying drawings, it should be understood that, without changing the technical concept or essential features of the present invention, a person skilled in the art can implement the present invention in other specific forms. Therefore, it should be understood that the above embodiments are exemplary in all aspects and not restrictive.

Claims

1. An arc extinguishing structure for a DC air circuit breaker, wherein: include: a plurality of cooling plates; A first side plate and a second side plate, two opposite side plates are respectively coupled to two sides of each cooling plate of the plurality of cooling plates, so that the plurality of cooling plates are stacked in a state of being spaced apart from each other; An exhaust hood, located above the first side plate, the second side plate and the plurality of cooling plates; a first arc guide and a second arc guide, each arc guide being respectively combined with one of the first side plate and the second side plate so that each arc guide is located at a lower portion of the plurality of cooling plates; as well as a first magnet and a second magnet, each magnet being coupled to one of the arc guides, Each magnet is magnetized to have an upper portion and a lower portion with different poles based on the vertical arrangement direction of the plurality of cooling plates and the one arc guide, and the upper portions of the first magnet and the second magnet have the same pole.

2. The arc extinguishing structure for a DC air circuit breaker according to claim 1, wherein: A magnet insertion groove in which one magnet is seated is formed in each arc guide, the one magnet extending along the stacking direction of the plurality of cooling plates, and the magnet insertion groove extending along the stacking direction of the plurality of cooling plates.

3. The arc extinguishing structure for a DC air circuit breaker according to claim 2, wherein: Each cooling plate is formed at a lower portion thereof with a downwardly inclined portion having an inner side surface inclined outwardly as extending from a central portion toward each of two opposite end portions, Each arc guide is also formed with a guide plate portion including an upwardly inclined portion facing the downwardly inclined portion.

4. The arc extinguishing structure for a DC air circuit breaker according to claim 2, wherein: A side plate fixing portion is formed in the magnet insertion groove, and an arc guide fixing portion corresponding to the side plate fixing portion is formed on each of the first side plate and the second side plate.

5. The arc extinguishing structure for a DC air circuit breaker according to claim 4, wherein: The side plate fixing portion and the arc guide fixing portion are formed as through holes.

6. The arc extinguishing structure for a DC air circuit breaker according to claim 5, wherein: The first magnet is formed to extend along the length direction of the first arc guide and is formed with a mounting hole corresponding to the through hole. The arc extinguishing portion structure also includes a fixing component for combining the arc guide fixing portion, the mounting hole and the side plate fixing portion, and when the first magnet is placed in the corresponding magnet insertion slot, the fixing component fixes the first arc guide to the first side plate.

7. The arc extinguishing structure for a DC air circuit breaker according to claim 2, wherein: The upper portion of each magnet is magnetized to an S pole, and the lower portion thereof is magnetized to an N pole.

8. The arc extinguishing structure for a DC air circuit breaker according to claim 2, wherein: The plate portion of each arc guide having the magnet insertion slot formed therein is formed so that the width of one side is greater than the width of the other side. The magnet insertion groove is formed to have a width of one side greater than a width of the other side, and the magnet coupled to the magnet insertion groove has a width of one side greater than a width of the other side.

9. The arc extinguishing structure for a DC air circuit breaker according to claim 1, wherein: Each arc guide is formed with a plurality of magnet insertion slots for accommodating the plurality of magnets and a side plate fixing portion formed between the plurality of magnet insertion slots. An arc guide fixing portion corresponding to the side plate fixing portion is formed on each of the first side plate and the second side plate.

10. The arc extinguishing structure for a DC air circuit breaker according to claim 9, wherein: The side plate fixing portion and the arc guide fixing portion are formed as through holes.

11. The arc extinguishing structure for a DC air circuit breaker according to claim 10, wherein: A fixing member for combining the arc guide fixing portion and the side plate fixing portion is further included, and the fixing member fixes the arc guide to each of the first side plate and the second side plate in a state where the magnet is seated in the magnet insertion groove.

12. The arc extinguishing structure for a DC air circuit breaker according to claim 8, wherein: The upper portion of each magnet is magnetized to an S pole, and the lower portion thereof is magnetized to an N pole.

13. The arc extinguishing structure for a DC air circuit breaker according to claim 9, wherein: Each arc guide is formed to extend from one side to the other side in the length direction and extends downward from one side, and the magnet insertion slot is formed with a first magnet insertion slot extending downward from one side of the arc guide and a second magnet insertion slot extending from one side of the arc guide to the other side thereof, The magnet includes the first magnet formed to extend downward to correspond to the first magnet insertion groove and the second magnet formed to extend in the length direction to correspond to the second magnet insertion groove.

14. The arc extinguishing structure for a DC air circuit breaker according to claim 9, wherein: Each cooling plate is formed at a lower portion thereof with a downwardly inclined portion having an inner side surface inclined outwardly as the downwardly inclined portion extends from a central portion toward each of two opposite end portions, The arc guide is also formed with a guide plate portion having an upwardly inclined portion facing the downwardly inclined portion.

15. The arc extinguishing structure for a DC air circuit breaker according to claim 1, wherein: The moving trajectory of the movable contact related to the arc extinguishing portion structure is orthogonal to the magnetization directions of the first magnet and the second magnet.

16. An arc extinguishing structure for a DC air circuit breaker, wherein: include: first side panel; Second side panel; an exhaust hood connected to the first side panel and the second side panel; a first arc guide connected to an end of the first side plate opposite to the connection with the exhaust hood; a second arc guide connected to an end of the second side plate opposite to the connection with the exhaust hood; a plurality of cooling plates evenly spaced from each other, each cooling plate being connected to a first surface of the first side plate and a second surface of the second side plate parallel to the first surface, and being located between the exhaust hood, the first arc guide, and the second arc guide; a first magnet coupled to the first arc guide and the first surface of the first side plate; as well as a second magnet coupled to the second arc guide and the second surface of the second side plate, Each of the first magnet and the second magnet is oriented with a first pole and a second pole separated from each other on a polarity plane perpendicular to the first face and the second face, with the first pole located on a common plane of the polarity planes.

17. The arc extinguishing structure for a DC air circuit breaker according to claim 16, wherein: The moving trajectory of the movable contact related to the arc extinguishing portion structure is orthogonal to the magnetization directions of the first magnet and the second magnet.

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