Arc extinguishing structure of a small circuit breaker

Abstract

The present invention provides an arc extinguishing structure of a small circuit breaker, comprising a housing, a static contact, two arc-isolating plates, an arc-strike component and an arc-extinguishing chamber arranged in the housing, wherein the two arc-isolating plates are arranged on both sides of the static contact, the arc-strike component is suitable for guiding the arc to the arc-extinguishing chamber, and a limiting structure suitable for limiting the position of the arc-isolating plates is arranged between the arc-strike component and the arc-isolating plates. The relative positions of the two arc-isolating plates are thereby limited so that the spacing between the two arc-isolating plates is maintained at a preset optimal spacing, thereby increasing the stability of the airflow and improving the reliability of arc extinguishing.

Description

Technical Field

[0001] The invention relates to the technical field of low-voltage electrical appliances, and in particular to an arc extinguishing structure of a small circuit breaker. Background Art

[0002] A small circuit breaker refers to a protective device installed in a terminal distribution line, mainly used for overload and short-circuit protection of lines and electrical equipment.

[0003] The contact mechanism of a small circuit breaker generates an arc when it is disconnected. In order to achieve rapid arc extinguishing, magnetic conductive plates are generally provided on both sides of the static contact to blow the arc to the arc extinguishing chamber, and arc isolation plates are also provided between the magnetic conductive plates and the static contact to prevent the arc from jumping onto the magnetic conductive plates and burning them. The inventor found in actual use that due to the shaking of the product during handling, transportation and installation, the relative positions of the two arc isolation plates on both sides of the static contact will change, that is, the spacing between the two arc isolation plates will deviate from the preset optimal spacing, which will reduce the stability of the airflow and the arc extinguishing effect will be average. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art that the relative positions of the two arc-isolating plates will change, reduce the airflow stability, and cause the arc extinguishing effect to be one plate, thereby providing an arc extinguishing structure for a small circuit breaker with high arc extinguishing reliability.

[0005] To this end, the present invention provides an arc extinguishing structure for a small circuit breaker, comprising a shell, and a static contact, two arc-isolating plates, an arc-strike component and an arc-extinguishing chamber arranged in the shell, the two arc-isolating plates are arranged on both sides of the static contact, the arc-strike component is suitable for guiding the arc to the arc-extinguishing chamber, and a limiting structure suitable for limiting the position of the arc-isolating plate is provided between the arc-strike component and the arc-isolating plate.

[0006] The limiting structure includes two first positioning bosses respectively arranged on both sides of the arc-starting member in the width direction, and the two first positioning bosses extend to abut against the corresponding arc-isolating plates.

[0007] The arc isolation plate is formed with a first positioning groove matched with the first positioning boss.

[0008] The limiting structure includes a first positioning boss arranged on the inner side of the arc isolation plate, and the first positioning boss extends to abut against the arc-starting member.

[0009] The arc-starting member is formed with a first positioning groove which cooperates with the first positioning boss.

[0010] The arc-starting member is arranged between the two arc-isolating plates, and the first positioning boss extends along the Z-axis direction of the shell.

[0011] The arc-striking member is arranged between the two arc-isolating plates, and two side surfaces of the arc-striking member in the width direction are respectively against the corresponding inner side surfaces of the arc-isolating plates.

[0012] The arc-striking member comprises an arc-striking foot and an arc-striking sheet respectively arranged on both sides of the arc-extinguishing chamber opening, the arc-striking foot is connected to the static contact, and the limiting structure is arranged between the arc-striking foot and / or the arc-striking sheet and the arc-isolating plate.

[0013] A magnetic conductive plate is provided on one side of the arc isolation plate away from the static contact, a positioning structure is provided between the arc isolation plate and the housing, and the positioning structure is arranged outside the positive projection of the magnetic conductive plate on the arc isolation plate.

[0014] The positioning structure includes a positioning column or a positioning hole provided on the shell, and a positioning hole or a positioning column provided on the magnetic conductive plate and matched therewith.

[0015] The technical solution of the present invention has the following advantages:

[0016] 1. The arc extinguishing structure of the miniature circuit breaker provided by the present invention defines the relative position of the two arc isolation plates by setting a limiting structure between the arc striking member and the arc isolation plate, so that the distance between the two arc isolation plates is maintained at a preset optimal distance, thereby increasing the stability of the airflow and improving the reliability of arc extinguishing.

[0017] 2. The arc extinguishing structure of the miniature circuit breaker provided by the present invention is provided with a first positioning boss on one side of the arc striking member and the arc isolating plate, and a first positioning groove cooperating therewith is provided on the other side, so that the assembly is quick and convenient, and the position of the arc isolating plate on the housing is limited.

[0018] 3. The arc extinguishing structure of the small circuit breaker provided by the present invention has an arc-striking member arranged between two arc-isolating plates, and the first positioning boss extends along the Z-axis direction of the shell. In this way, the width of the arc-striking member can be set smaller, and the resistance of the arc-striking member will become smaller, thereby reducing the voltage of the arc, which is beneficial to increasing the flow speed of the arc and improving the arc extinguishing effect.

[0019] 4. The arc extinguishing structure of the small circuit breaker provided by the present invention has a positioning structure between the arc isolation plate and the shell, and the positioning structure is arranged outside the positive projection of the magnetic plate on the arc isolation plate, that is, the positioning structure is located at the peripheral position of the magnetic plate. This avoids the method of drilling a hole in the middle of the magnetic plate in the prior art, thereby ensuring the uniformity and internal integrity of the magnetic field, which is beneficial to the rapid flow of the arc and further improves the arc extinguishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a miniature circuit breaker of the present invention;

[0022] Figure 2 for Figure 1 A schematic diagram of the structure after some arc isolation plates and magnetic conductive plates are removed;

[0023] Figure 3 It is a schematic diagram of the assembly of arc isolation plate, magnetic conductive plate and arc starting member;

[0024] Figure 4 for Figure 3 A schematic diagram of the structure after some arc isolation plates and magnetic conductive plates are removed;

[0025] Figure 5 It is a schematic diagram of the structure of two arc isolation plates and two magnetic conductive plates;

[0026] Figure 6 It is a three-dimensional diagram of the arc isolation plate;

[0027] Figure 7 for Figure 6 A schematic diagram of the enlarged structure of part A;

[0028] Figure 8 It is a three-dimensional picture of the arc-starting sheet;

[0029] Fig. 9 is a schematic diagram of the structure of the shell;

[0030] Fig.10 A three-dimensional diagram of a miniature circuit breaker.

[0031] Explanation of the reference numerals in the accompanying drawings: 1. housing; 2. static contact; 3. arc-isolating plate; 4. arc-striking member; 5. arc-extinguishing chamber; 6. first positioning boss; 7. first positioning groove; 8. arc-striking foot; 9. arc-striking sheet; 10. magnetic conductive plate; 11. positioning column; 12. positioning hole; 13. arc-striking plate; 14. conductive member; 15. static contact; 16. slot; 17. first stopper; 18. blocking surface; 19. guiding slope; 20. second positioning boss; 21. second positioning groove; 22. main plate; 23. side plate; 24. second stopper; 25. arc-striking channel; 26. bell mouth. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Example

[0037] This embodiment provides a miniature circuit breaker, such as Figure 1 and 2 As shown, it includes a shell 1, and a conductive member 14, an arc-starting member 4, an arc-isolating plate 3, a magnetic conductive plate 10 and an arc-extinguishing chamber 5 arranged on the shell 1.

[0038] The conductive member 14 is disposed between the two arc isolation plates 3, such as Figure 2 and 4 As shown, it comprises a static contact 2 and an arc striking foot 8 connected in an integral bending manner, a static contact point 15 is provided on the static contact 2, and the arc striking foot 8 extends from the static contact 2 toward the arc extinguishing chamber 5.

[0039] The arc-starting member 4 is disposed between the two arc-isolating plates 3, and a limiting structure for limiting the position of the arc-isolating plates 3 is disposed between the arc-starting member 4 and the arc-isolating plates 3. Figure 3 and 8As shown, the arc-striking member 4 is an arc-striking piece 9 provided at the lower side of the opening of the arc-extinguishing chamber 5 and connected to the bimetallic strip. The arc-striking piece 9 has an arc-striking plate 13 extending obliquely upward from the opening of the arc-extinguishing chamber 5, and first positioning bosses 6 provided on both sides of the arc-striking plate 13 in the width direction. Fig.10 As shown, the two first positioning bosses 6 extend along the Z-axis direction of the housing 1 and extend to abut against the corresponding arc isolation plates 3. Since the arc-starting member 4 is disposed between the two arc isolation plates 3 and the first positioning bosses 6 extend along the Z-axis direction of the housing 1, the width of the arc-starting member 4 can be set smaller, and the resistance of the arc-starting member 4 will become smaller, thereby reducing the voltage of the arc, which is beneficial to increasing the flow speed of the arc and improving the arc extinguishing effect.

[0040] As a convertible implementation, the arc-striking member 4 is disposed between the two arc-isolating plates 3 , and the two side surfaces of the arc-striking member 4 in the width direction are respectively against the corresponding inner side surfaces of the arc-isolating plates 3 .

[0041] As a convertible embodiment, the arc-striking member 4 is an arc-striking foot 8 arranged on the upper side of the opening of the arc-extinguishing chamber 5, and the arc-striking foot 8 has a first positioning boss 6 (not shown in the figure) arranged on both sides of the width direction thereof, and the two first positioning bosses 6 extend to abut against the corresponding arc-isolating plates 3.

[0042] There are two arc isolation plates 3, and the arc isolation plates 3 are formed with first positioning grooves 7 that cooperate with the first positioning bosses 6. Figure 5 As shown, the arc isolation plate 3 includes a main body plate 22, and a side plate 23 vertically arranged at the edge of the main body plate 22, and the side plate 23 is provided with a second stopper 24 that can abut against the edge of the magnetic conductive plate 10 at one end away from the main body plate 22, and the second stopper 24 and the main body plate 22 are opposite to form a slot 16 for inserting the magnetic conductive plate 10, and the opening of the slot 16 is provided with a first stopper 17 that abuts against the magnetic conductive plate 10, as shown in FIG. Figure 6 and 7As shown, the first stopper 17 has a blocking surface 18 disposed on one side to abut against the magnetic conductive plate 10, and a guiding inclined surface 19 disposed on the other side for inserting the magnetic conductive plate 10. The two arc isolation plates 3 are opposite to each other to form an arc striking channel 25, and a bell mouth 26 is disposed on one side of the arc striking channel 25 adjacent to the arc extinguishing chamber 5, and the diameter of the bell mouth 26 gradually increases from the opening of the arc extinguishing chamber 5 to the outside. A positioning structure is disposed between the arc isolation plate 3 and the housing 1, and the positioning structure is disposed outside the positive projection of the magnetic conductive plate 10 on the arc isolation plate 3, that is, the positioning structure is located at the peripheral position of the magnetic conductive plate 10, thus avoiding the method of drilling a hole in the middle of the magnetic conductive plate 10 in the prior art, thereby ensuring the uniformity and internal integrity of the magnetic field, facilitating the rapid flow of the arc, and improving the arc extinguishing effect. In this embodiment, the positioning structure is arranged above the top of the arc-striking plate 13. Since the left side of the arc-isolating plate 3 extends to the adjacent arc-extinguishing chamber 5, the upper side abuts against the second positioning boss 20 of the shell 1. Therefore, the positioning structure is arranged above the top of the arc-striking plate. The structure is more compact and the layout is reasonable. The positioning structure includes a positioning column 11 or a positioning hole arranged on the shell 1, and a positioning hole 12 or a positioning column arranged on the magnetic conductive plate 10 and matched therewith.

[0043] As a convertible embodiment, the limiting structure includes a first positioning boss 6 (not shown in the figure) provided on the inner side surface of the arc isolation plate 3 , and the first positioning boss 6 extends to abut against the arc-starting member 4 .

[0044] As a convertible embodiment, the limiting structure includes a first positioning boss 6 (not shown in the figure) arranged on the inner side of the arc isolation plate 3, and the arc-starting member 4 is formed with a first positioning groove 7 (not shown in the figure) that cooperates with the first positioning boss 6.

[0045] As a convertible implementation, the positioning structure is arranged on the edge of the arc isolation plate 3 .

[0046] There are two magnetic conductive plates 10, which are respectively arranged in the corresponding two arc isolation plates 3, and the magnetic conductive plates 10 are arranged on the side of the arc isolation plate 3 away from the static contact 2. The positive projection of the magnetic conductive plate 10 on the conductive member 14 covers the arc striking pin 8, and does not exceed the contact position between the static contact 15 and the moving contact, which is beneficial to the magnetic field at the arc striking pin 8, thereby facilitating the rapid flow of the arc, improving the arc extinguishing effect, and preventing the arc from flowing above the static contact 2, thereby avoiding the arc from damaging the mechanism.

[0047] like Fig. 9 As shown, a second positioning boss 20 that can abut against the top surface of the magnetic conductive plate 10 is formed on the shell 1, and a second positioning groove 21 that cooperates with the second positioning boss 20 is formed on the top of the arc isolation plate 3.

[0048] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An arc extinguishing structure for a small circuit breaker, comprising a housing (1), and a stationary contact (2), two arc isolation plates (3), an arc striking member (4) and an arc extinguishing chamber (5) arranged in the housing (1), wherein the two arc isolation plates (3) are arranged on both sides of the stationary contact (2), and the arc striking member (4) is suitable for guiding an arc to the arc extinguishing chamber (5), characterized in that: A limiting structure suitable for limiting the position of the arc isolation plate (3) is provided between the arc-striking member (4) and the arc isolation plate (3), the limiting structure comprising two first positioning bosses (6) respectively arranged on both sides of the arc-striking member (4) in the width direction, the two first positioning bosses (6) extending to abut against the corresponding arc isolation plates (3), and the arc isolation plate (3) is formed with a first positioning groove (7) cooperating with the first positioning boss (6); or the limiting structure comprises a first positioning boss (6) provided on the inner side surface of the arc isolation plate (3), the first positioning boss (6) extending to abut against the arc-striking member (4), and the arc-striking member (4) is formed with a first positioning groove (7) cooperating with the first positioning boss (6).

2. The arc extinguishing structure of a miniature circuit breaker according to claim 1, characterized in that: The arc-starting member (4) is arranged between the two arc-isolating plates (3), and the first positioning boss (6) extends along the Z-axis direction of the housing (1).

3. The arc extinguishing structure of a miniature circuit breaker according to claim 1, characterized in that: The arc-starting member (4) is arranged between the two arc-isolating plates (3), and two side surfaces of the arc-starting member (4) in the width direction respectively abut against the corresponding inner side surfaces of the arc-isolating plates (3).

4. The arc extinguishing structure of a miniature circuit breaker according to claim 1, characterized in that: The arc-striking member (4) comprises an arc-striking foot (8) and an arc-striking sheet (9) respectively arranged on both sides of an opening of the arc-extinguishing chamber (5); the arc-striking foot (8) is connected to the stationary contact (2); and the limiting structure is provided between the arc-striking foot (8) and / or the arc-striking sheet (9) and the arc-isolating plate (3).

5. The arc extinguishing structure of a miniature circuit breaker according to claim 1, characterized in that: A magnetic conductive plate (10) is provided on a side of the arc isolation plate (3) away from the static contact (2), a positioning structure is provided between the arc isolation plate (3) and the housing (1), and the positioning structure is provided outside the positive projection of the magnetic conductive plate (10) on the arc isolation plate (3).

6. The arc extinguishing structure of a miniature circuit breaker according to claim 5, characterized in that: The positioning structure comprises a positioning column (11) or a positioning hole provided on the housing (1), and a positioning hole (12) or a positioning column provided on the magnetic conductive plate (10) and cooperating therewith.

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