Circuit breaker

Abstract

A circuit breaker belongs to the technical field of low-voltage apparatuses. Comprising a moving and static contact pair and an arc extinguishing device arranged corresponding to the moving and static contact pair, the arc extinguishing device comprises a first arc extinguishing chamber and a second arc extinguishing chamber which are oppositely arranged, and an arc striking piece is arranged between the first arc extinguishing chamber and the second arc extinguishing chamber; the arc striking piece is provided with a top part facing the movable and static contact pair, a first arc striking sheet close to the first arc extinguishing chamber and a second arc striking sheet close to the second arc extinguishing chamber, an opening is formed in the top part, and two sides of the opening are respectively connected by the first arc striking sheet and the second arc striking sheet to form a pair of connecting parts; the first arc striking sheet and the second arc striking sheet are disconnected through an opening between the pair of connecting parts, and the arc extinguishing device further comprises an insulating part which covers the pair of connecting parts so as to separate the connecting parts from the moving and static contact pair. The arc extinguishing chamber has the advantage of effectively accelerating the transfer speed of the arc from the contact to the arc extinguishing chamber.

Description

Technical Field

[0001] The utility model belongs to the technical field of low-voltage electrical appliances, and particularly relates to a circuit breaker. Background Art

[0002] A circuit breaker is an important control and protection electrical appliance in a power supply and distribution system. It realizes the connection or disconnection of a circuit by the closing or separation of a pair of separable contact pairs (a moving contact and a static contact) to protect the circuit and electrical equipment. When abnormal conditions such as short circuit or overload occur in the circuit, the circuit is quickly disconnected by the separation of the contact pair. As is known in the industry, when carrying current, an arc will be generated when the contact pair separates. Especially when disconnecting a short-circuit current, due to the large energy of the arc, the contacts are easily ablated. Therefore, an arc extinguishing device is usually provided in switching electrical appliances such as circuit breakers and contactors, and the arc is extinguished by the arc extinguishing device to ensure the safe operation of electrical equipment.

[0003] European Patent EP1191565B1 discloses an arc extinguishing device. In a circuit breaker housing, two arc extinguishing chambers are provided corresponding to the contacts to the ground, and they are placed facing each other. An arc guiding member is provided between the two arc extinguishing chambers. When a fault current, such as a large current caused by a short circuit, passes through, the moving contact and the static contact separate, and an arc is generated between the moving contact point of the moving contact and the static contact point of the static contact. Under the well-known arc blowing action, the arc moves towards the arc guiding member, elongates, and after contacting the vertex of the arc guiding member, it is cut into two segments. The first segment of the arc enters the first arc extinguishing chamber, and the second segment of the arc enters the second arc extinguishing chamber. The two segments of the arc move towards each other, and after entering the corresponding arc extinguishing chambers respectively, they are cooled and extinguished in the arc extinguishing chambers.

[0004] However, the above arc extinguishing device structure has the following drawbacks: After the arc is guided by the arc guiding piece, since the electric field strength of an equipotential body will concentrate at the sharp corners, the arc will stay at the tip of the top of the arc guiding member, which is not conducive to the rapid movement of the arc, and it is also difficult for the arc guiding member to quickly divide the arc into two segments of arcs and enter the corresponding side arc extinguishing chambers respectively.

[0005] In view of the above existing technologies, it is necessary to reasonably improve the existing circuit breaker to solve the above problems. For this reason, the applicant has made a beneficial design, and the technical solution to be introduced below is generated under this background. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a circuit breaker, which can effectively accelerate the transfer speed of the arc from the contact to the arc extinguishing chamber.

[0007] The object of the present utility model is achieved in the following way. A circuit breaker includes a moving and a static contact pair and an arc extinguishing device arranged corresponding to the moving and static contact pair. The arc extinguishing device includes a first arc extinguishing chamber and a second arc extinguishing chamber arranged opposite to each other. An arc guiding member is provided between the first arc extinguishing chamber and the second arc extinguishing chamber. The arc guiding member has a top protruding towards the moving and static contact pair, a first arc guiding piece close to the first arc extinguishing chamber, and a second arc guiding piece close to the second arc extinguishing chamber. An opening is provided on the top. On both sides of the opening, a pair of connecting parts are formed by connecting the first arc guiding piece and the second arc guiding piece respectively. Between the pair of connecting parts, the first arc guiding piece and the second arc guiding piece are disconnected by the opening. The arc extinguishing device further includes an insulating member covering the pair of connecting parts to separate the connecting parts from the moving and static contact pair.

[0008] In an embodiment of the present utility model, the circuit breaker includes a housing. Two exhaust ports are provided on the side wall of the housing. One of the two exhaust ports is located on the side of the first arc extinguishing chamber away from the second arc extinguishing chamber, and the other of the two exhaust ports is located on the side of the second arc extinguishing chamber away from the first arc extinguishing chamber.

[0009] In another embodiment of the present utility model, the arc guiding member is in a ∧ shape or a ∩ shape.

[0010] In still another embodiment of the present utility model, the circuit breaker further includes a pair of insulating side plates. The pair of insulating side plates are respectively arranged on both sides of the moving and static contact pair and cover the arc burning area and the arc running area. The edges away from the moving and static contact pair constitute an insulating member covering the connecting parts to separate the connecting parts from the moving and static contact pair.

[0011] The present utility model provides an opening on the top of the arc guiding member. On both sides of the opening, a pair of connecting parts are formed by connecting the first arc guiding piece and the second arc guiding piece respectively. Between the pair of connecting parts, the first arc guiding piece and the second arc guiding piece are disconnected by the opening. And a pair of connecting parts are covered by an insulating member to separate the connecting parts from the moving and static contact pair. The beneficial effects of adopting the above structure are as follows: When the arc guiding member guides the arc generated between the moving and static contact pair, since the arc contacts the opening on the top of the arc guiding member, there is no tip effect, so the retention of the arc is prevented, which is beneficial to the rapid movement of the arc. In addition, the pair of connecting parts are covered by the insulating member to prevent the arc from landing on the connecting parts, ensuring the only path for the arc to land from the opening. At the same time, the first arc guiding piece and the second arc guiding piece are connected on both sides of the opening, that is, the first arc guiding piece and the second arc guiding piece are at the same potential, and are disconnected at the opening. Thus, the arc can be easily divided into two segments at the beginning of landing, and then the two segments of the arc are respectively introduced into the first arc extinguishing chamber and the second arc extinguishing chamber through the first arc guiding piece close to the first arc extinguishing chamber and the second arc guiding piece close to the second arc extinguishing chamber, effectively accelerating the speed of the arc transfer from the contact to the arc extinguishing chamber. Description of the Drawings

[0012] Figure 1 Schematic diagram of the interior of the circuit breaker housing mentioned in the present utility model, including a moving and static contact pair and an arc extinguishing device;

[0013] Figure 2 Stereoscopic view of the cooperation between the moving and static contact pair and the arc extinguishing device mentioned in the present utility model;

[0014] Figure 3 Schematic diagram of the cooperation between the moving contact, insulating side plate, first grid piece and arc guiding piece of the present utility model;

[0015] Figure 4 Stereoscopic view of the arc guiding piece mentioned in the present utility model. Specific embodiments

[0016] The following describes in detail the specific embodiments of the present utility model in conjunction with the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any change in form rather than substance based on the concept of the present utility model should be regarded as the protection scope of the present utility model.

[0017] In the following description, any concepts related to directions (or orientations) such as up, down, left, right, front and back are with respect to the position state of the figure being described, aiming to facilitate public understanding. Therefore, it cannot be understood as a special limitation on the technical solution provided by the present utility model.

[0018] The present utility model relates to a circuit breaker, such as Figure 1 , the circuit breaker includes a moving and static contact pair 1, an arc extinguishing device 2, an operating mechanism, a tripping device, and a housing 4 for accommodating the above components. The moving and static contact pair 1 includes a moving contact 11 and a static contact 12. In this embodiment, in Figure 1 the height direction of the circuit breaker shown, the operating mechanism and the tripping mechanism are arranged in the upper part of the inner cavity of the housing 4. One end of the moving contact 11 is located in the upper part of the inner cavity of the housing 4 and is connected to the operating mechanism. The other end of the moving contact 11 extends into the lower part of the cavity of the housing 4. The moving contact on the moving contact 11 cooperates with the static contact also located in the lower part of the cavity of the housing 4. The separation and closing of the moving and static contact pair 1 realize the disconnection and connection of the circuit. The lower part of the inner cavity of the housing 4 forms an arc extinguishing device cavity 41 for accommodating the arc extinguishing device 2. The arc extinguishing device 2 is arranged corresponding to the moving and static contact pair 1 and is used to extinguish the arc generated between the moving and static contacts when the moving and static contact pair 1 separates.

[0019] Such as Figure 2 shown, and in combination with Figure 1 , the arc extinguishing device 2 includes a first arc extinguishing chamber 21 and a second arc extinguishing chamber 22 arranged opposite to each other. In this embodiment, as Figure 1As shown, the first arc extinguishing chamber 21 is located at the left end of the arc extinguishing device cavity 41, and the second arc extinguishing chamber 22 is located at the right end of the arc extinguishing device cavity 41. It can be seen that the first arc extinguishing chamber 21 and the second arc extinguishing chamber 22 are arranged along the movement direction of the moving contact 11 in the moving and static contact pair 1, which can be understood as Figure 1 the width direction of the circuit breaker shown. The first arc extinguishing chamber 21 has several stacked grid plates 211. The grid plates 211 are offset relative to the perpendicular line perpendicular to the bottom wall 411 of the arc extinguishing device cavity 41. In this embodiment, it deflects clockwise relative to the perpendicular line, and the deflection angles of each grid plate 211 are the same; the second arc extinguishing chamber 22 has several stacked grid plates 221. Each grid plate 221 is arranged substantially parallel to the bottom wall 411 of the arc extinguishing device cavity 41. The several grid plates 221 form a grid plate group stacked in the vertical direction of the circuit breaker, that is, in the direction of the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41.

[0020] See Figure 1 and Figure 4 , there is an arc guiding member 3 between the first arc extinguishing chamber 21 and the second arc extinguishing chamber 22. The arc guiding member 3 has a top 30 protruding towards the moving and static contact pair 1, a first arc guiding plate 31 close to the first arc extinguishing chamber 21, and a second arc guiding plate 32 close to the second arc extinguishing chamber 22. As a feature of the present invention: there is an opening 33 on the top 30. Both sides of the opening 33 respectively have a pair of connecting portions 301 formed by connecting the first arc guiding plate 31 and the second arc guiding plate 32. The first arc guiding plate 31 and the second arc guiding plate 32 are disconnected by the opening 33 between the pair of connecting portions 301. A connecting portion 301, the opening 33, and the other connecting portion 301 are arranged in sequence in the direction perpendicular to the perpendicular line of the plane swept by the movement of the moving contact 11 in the moving and static contact pair 1 (that is, the direction perpendicular to the paper surface). It can be seen that the opening 33 is located between the pair of connecting portions 301. In this embodiment, the first arc guiding plate 31 is located on the left side of the top 30; the second arc guiding plate 32 is located on the right side of the top 30, and further, the biasing direction and biasing angle of the first arc guiding plate 31 are the same as those of the grid plates 211. Furthermore, the spacing distances between the several stacked grid plates 211 and between the grid plates 211 and the first arc guiding plate 31 are the same. Thus, the arc guiding member 3 is in a ∧ shape. In this embodiment, the second arc guiding plate 32 on the right side is also bent and extends below the bottommost grid plate 221 in the second arc extinguishing chamber 22.

[0021] See Figure 1 and Figure 2, the circuit breaker of the present utility model further includes a pair of insulating side plates 5, and the pair of insulating side plates 5 are respectively arranged on both sides of the moving and static contact pair 1 and cover the arc combustion area 6 (the area where an arc is generated between the moving and static contacts) and the arc running area 7 (the area where the arc moves from the generation towards the grid pieces 211 and 221 of the arc extinguishing device). In this embodiment, the edge of each insulating side plate 5 away from the moving and static contact pair 1 extends to the end of the cutting part on the grid piece 211. At the same time, the edge of it away from the moving and static contact pair 1 constitutes an insulating part covering the connecting part 301, separating the connecting part 301 on this side from the moving and static contact pair 1. Thus, as Figure 3 , a pair of insulating side plates 5 form a narrow slit 50 on both sides of the moving and static contact pair 1 to utilize the air blowing effect to accelerate the movement of the arc towards the arc extinguishing chamber. Further, a gas generating material can be covered on the mutually facing surfaces of the pair of insulating side plates 5; magnetic conductive plates can also be respectively arranged on the outer sides of the pair of insulating plates 5, or magnetic conductive plates can be embedded inside the insulating side plates 5 (that is, magnetic conductive plates are respectively arranged on both sides of the moving and static contact pair 1, and then the magnetic conductive plates are integrally coated with insulating materials), so as to further superimpose the magnetic blowing effect to accelerate the movement of the arc towards the arc extinguishing chamber. Fixing plates 23 are provided on both sides of the grid piece 211 for fixing multiple grid pieces 211, and fixing plates 23 are also provided on both sides of the grid piece 221. Of course, the fixing plate 23 of the grid piece 211 and the fixing plate 23 of the grid piece 221 can be integrally formed by one plate on the same side, and the integrally formed fixing plate 23 can simultaneously fix one side of the grid piece 211, the arc leading piece 3 and the grid piece 221. Further, the insulating side plates 5 and the fixing plates 23 can also be integrally formed. The part of the edge of the insulating side plate 5 away from the moving and static contact pair 1 corresponding to the second arc leading piece 32 can also extend to the upper end surface of the second arc leading piece 32 and at the same time extend to the end of the cutting part on the grid piece 221, so that both the arc running area moving towards the grid piece 211 and the arc running area moving towards the grid piece 221 form narrow slits.

[0022] Continue to see Figure 1 , a moving contact arc leading piece 13 and a static contact arc leading piece 14 are also provided in the circuit breaker. The moving contact arc leading piece 13 is arranged close to the moving contact 11 during opening, and its end extends to the left side of the first arc extinguishing chamber 21. The static contact arc leading piece 14 is connected to the static contact 12 and extends above the second arc extinguishing chamber 22.

[0023] Two exhaust ports 412 are provided on the side wall of the arc extinguishing device cavity 41 of the circuit breaker. One of the two exhaust ports 412 is located on the side of the first arc extinguishing chamber 21 away from the second arc extinguishing chamber 22, and the other of the two exhaust ports 412 is located on the side of the second arc extinguishing chamber 22 away from the first arc extinguishing chamber 21. A deionization device 8 is provided between the first arc extinguishing chamber 21 and the corresponding exhaust port 412. Similarly, a deionization device 8 is also provided between the second arc extinguishing chamber 22 and the corresponding exhaust port 412.

[0024] When a fault current is generated in the circuit, the moving contact 11 and the stationary contact 12 are separated, and an arc is generated between the moving contact and the stationary contact. Under the action of air blowing and magnetic blowing, the arc moves in the arc running area 7, and the arc root on the stationary contact moves along the stationary contact arc starting piece 14. The arc root on the moving contact jumps from the arc angle at the end of the moving contact 11 to the moving contact arc starting piece 13, and the middle part of the arc is connected by the arc starting piece 3. Since the arc contacts the opening 33 on the top 30 of the arc starting piece 3, there is no tip effect and the arc will not stay there. The circuit breaker also uses an insulating member to cover a pair of connecting parts 301, thereby preventing the arc from landing from the connecting parts 301, ensuring that the arc has the only path to land from the opening 33. At the same time, the first arc-starting piece 31 and the second arc-starting piece 32 are connected on both sides of the opening 33, that is, the first arc-starting piece 31 and the second arc-starting piece 32 are of the same potential, but are disconnected at the opening 33, thereby making it easy for the arc to be divided into two sections at the beginning of landing, and then the two sections of the arc are respectively introduced into the first arc-extinguishing chamber 21 and the second arc-extinguishing chamber 22 through the first arc-starting piece 31 close to the first arc-extinguishing chamber 21 and the second arc-starting piece 32 close to the second arc-extinguishing chamber 22. Figure 1 , thus effectively accelerating the speed of the arc transfer from the contact to the arc extinguishing chamber. After the left arc section entering the first arc extinguishing chamber 21 is cut by the grid piece 1 211, it is stretched and cooled, and the high-temperature metal gas formed by the arc is deionized and further cooled by the deionization device 8 on the left side and then discharged from the circuit breaker through the exhaust port 412 on the left side; after the right arc section entering the second arc extinguishing chamber 22 is cut by the grid piece 221, it is stretched and cooled, and the high-temperature metal gas formed by the arc is deionized and further cooled by the deionization device 8 on the right side and then discharged from the circuit breaker through the exhaust port 412 on the right side.

[0025] In the above embodiment, the grid piece 1 211 is deflected counterclockwise relative to the vertical line perpendicular to the bottom wall 411 of the arc extinguishing device cavity 41, and the deflection angle is an acute angle, while the grid piece 221 is arranged parallel to the bottom wall 411 of the arc extinguishing device cavity 41, which is equivalent to the grid piece 221 being deflected 90° counterclockwise relative to the vertical line perpendicular to the bottom wall 411 of the arc extinguishing device cavity 41. The circuit breaker of the utility model is certainly not limited to the above embodiment, and the grid piece 1 211 can also be deflected 90° clockwise relative to the vertical line perpendicular to the bottom wall 411 of the arc extinguishing device cavity 41, that is, it is formed at the height of the circuit breaker (borrowed from Figure 1 A group of arc extinguishing grids are stacked in the direction of viewing angle. At the same time, the grid 221 is deflected 90° counterclockwise relative to the vertical line perpendicular to the bottom wall 411 of the arc extinguishing device cavity 41, that is, it is formed at the height of the circuit breaker (borrowed from Figure 1Another set of arc extinguishing grid plate groups arranged in a stacked manner in the (viewpoint of Figure 1 the same are provided on the side side walls. It is also possible that the grid plate 211 is deflected 90° clockwise with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41, and the grid plate 221 is deflected counterclockwise by an acute angle with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41. The arc ignition member 3 is arranged between the two arc extinguishing chambers and is in a ∧ shape or a ∩ shape. In this structure, the exhaust port 412 is as Figure 1 the same are provided on the side side walls. It is also possible that the grid plate 211 is deflected counterclockwise by an acute angle with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41, and the grid plate 221 is deflected 90° counterclockwise with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41. The arc ignition member 3 is arranged between the two arc extinguishing chambers and is in a shape. In this structure, the exhaust port 412 is provided on the right side wall. It is also possible that the grid plate 211 is deflected clockwise by an acute angle with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41, and the deflection angles of each grid plate 211 are the same. The grid plate 221 is deflected counterclockwise by an acute angle with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41, and the deflection angles of each grid plate 221 are the same. Thus, the biasing directions of the above-mentioned grid plate 211 and grid plate 221 are opposite, and furthermore, the biasing direction and biasing angle of the first arc ignition plate 31 are the same as those of the grid plate 211. Further, the spacing distances between the multiple stacked grid plates 211, between the grid plate 211 and the first arc ignition plate 31 are the same; the biasing direction and biasing angle of the second arc ignition plate 32 are the same as those of the grid plate 221. Further, the spacing distances between the multiple stacked grid plates 221, between the grid plate 221 and the second arc ignition plate 32 are the same. In this structure, the exhaust port 412 is as Figure 1 the same are provided on the side side walls. It is also possible that the grid plates in one arc extinguishing chamber are biased with respect to the perpendicular line of the bottom wall 411 of the arc extinguishing device cavity 41, while the grid plates in the other arc extinguishing chamber are not biased, that is, multiple grid plates are stacked along the width direction of the circuit breaker (borrowing Figure 1 the viewpoint). Therefore, the grid plate 211 and the grid plate 221 of the present utility model can have different biasing directions, and the biasing angles between each grid plate and the spacing distances between each grid plate can also be different.

Claims

1. A circuit breaker, comprising a moving and a static contact pair (1) and an arc extinguishing device (2) arranged corresponding to the moving and static contact pair (1). The arc extinguishing device (2) includes a first arc extinguishing chamber (21) and a second arc extinguishing chamber (22) arranged oppositely. An arc guiding member (3) is provided between the first arc extinguishing chamber (21) and the second arc extinguishing chamber (22). The arc guiding member (3) has a top (30) protruding towards the moving and static contact pair (1), a first arc guiding piece (31) close to the first arc extinguishing chamber (21), and a second arc guiding piece (32) close to the second arc extinguishing chamber (22), and is characterized in that: An opening (33) is provided on the top (30). On both sides of the opening (33), a pair of connecting parts (301) are formed by connecting a first arcing piece (31) and a second arcing piece (32) respectively. The first arcing piece (31) and the second arcing piece (32) are disconnected by the opening (33) between the pair of connecting parts (301). The arc extinguishing device (2) further includes an insulating part that covers the pair of connecting parts (301) to separate the connecting parts (301) from the moving and static contact pair (1).

2. The circuit breaker according to claim 1, characterized in that: It includes a housing (4). Two exhaust ports (412) are provided on the side wall of the housing (4). One of the two exhaust ports (412) is located on the side of the first arc extinguishing chamber (21) away from the second arc extinguishing chamber (22), and the other of the two exhaust ports (412) is located on the side of the second arc extinguishing chamber (22) away from the first arc extinguishing chamber (21).

3. The circuit breaker according to claim 1, characterized in that: The arcing part (3) is in the shape of ∧ or ∩.

4. A circuit breaker according to claim 1, characterized in that: It further includes a pair of insulating side plates (5). The pair of insulating side plates (5) are respectively arranged on both sides of the moving and static contact pair (1) and cover the arcing area (6) and the arc running area (7). The edges away from the moving and static contact pair (1) form an insulating part that covers the connecting part (301) to separate the connecting part (301) from the moving and static contact pair (1).

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