Circuit breaker

Abstract

The invention provides a circuit breaker, which at least comprises an insulating shell and internal elements, the internal elements at least comprise an arc extinguish chamber, a static contact, a moving contact, a wiring terminal, an operating mechanism and an arc striking sheet, the arc extinguish chamber is formed by superposing a plurality of metal arc extinguishing grid sheets, and the arc striking sheet and the static contact are integrally arranged. The connecting conductor between the static contact and the wiring terminal is provided with at least one magnet yoke, the magnet yoke is U-shaped or U-shaped, and the opening of the magnet yoke faces the metal arc extinguishing grid sheet or / and the arc striking sheet of the arc extinguishing chamber. When current passes through the connecting conductor, a magnetic field can be generated at the opening of the magnet yoke, and the magnetic field acts on the metal arc extinguishing grid sheet or / and the arc striking sheet to quickly attract an electric arc so as to promote the electric arc to quickly jump; when the moving contact leaves the static contact and generates an electric arc, the metal arc extinguishing grid piece or / and the arc striking piece with the magnetic field accelerates the electric arc generated on the static contact to move towards the metal arc extinguishing grid piece or / and the arc striking piece, and the electric arc deionization effect is improved.

Description

Technical Field

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

[0002] Currently, circuit breakers on the market generally include operating mechanisms, moving contacts, static contacts, and arc extinguishing chambers. When the circuit breaker interrupts the fault current, an arc will be generated between the moving contact and the static contact. The arc is introduced into the arc extinguishing chamber by an arc-starting piece for arc extinguishing. When the moving contact and the static contact are opened to generate an arc, the arc will cause serious burning damage to the moving contact and the static contact. As the number of interruptions increases or the interrupting current is too high, the moving contact and the static contact will be permanently damaged.

[0003] In the prior art, for example: the arc pushing member of CN109755079 is sleeved on the arc striking plate and the static contact piece, and the current flowing through the arc striking member is used to generate an induced magnetic field for the arc pushing member to blow the arc. Another example: the U-shaped structure formed by the first magnetizing plate and the second magnetizing plate of CN217387061 U also uses the current flowing through the static arc striking plate to generate a magnetic field for the first magnetizing plate and the second magnetizing plate to blow the arc. Since the U-shaped magnetic conductive member of the prior art is sleeved on the arc striking plate, before the arc jumps from the moving contact to the arc striking plate and a current loop is formed on the arc striking plate, the U-shaped magnetic conductive member cannot generate a magnetic field for blowing the arc. Only when the arc jumps to the arc striking plate and current passes through the inside of the U-shaped magnetic conductive plate can an arc blowing magnetic field be generated. This delayed arc blowing method is not ideal, so the effect of improving the breaking capacity is not significant.

[0004] In conventional circuit breakers, when the arc has not yet jumped to the metal arc extinguishing grid or arc striking plate in the arc extinguishing chamber, the metal arc extinguishing grid or arc striking plate does not have a magnetic field. When the moving contact and the static contact are just opened, the metal arc extinguishing grid or arc striking plate lacks the magnetic attraction effect on the arc plasma, so that the speed at which the arc jumps to the metal arc extinguishing grid or arc striking plate is too slow, resulting in severe arc erosion of the moving contact and the static contact, and poor breaking capacity.

[0005] Figure 1 It is a partial structural diagram of an existing circuit breaker. Figure 2 for Figure 1 The breaking waveform of the circuit breaker during fault breaking. Figure 2 The vertical axis i represents the current and voltage values, and the horizontal axis t represents the time. When the existing circuit breaker is disconnected due to a fault, the moving contact and the static contact are separated, and an arc is generated between the moving contact and the static contact. Since there is no magnetic field around the arc extinguishing chamber, the arc can only enter the arc extinguishing chamber by relying on its own self-excitation magnetic field. Figure 2 It can be seen from the breaking waveform that the main feature is the time t0-t1 when the arc enters the arc extinguishing chamber. The time for the arc of the existing circuit breaker to enter the arc extinguishing chamber is obviously too long. Summary of the invention

[0006] Based on the above background, the present invention provides a circuit breaker. By arranging a magnetic yoke on the connecting conductor between the static contact and the terminal, the opening of the magnetic yoke faces the arc guide piece or / and the metal arc extinguishing grid pieces of the arc extinguishing chamber. When there is current passing through the connecting conductor, the magnetic yoke is magnetized, and the arc guide piece or / and the metal arc extinguishing grid pieces of the arc extinguishing chamber are magnetized by the magnetic yoke to generate a magnetic field to quickly attract the arc, promoting the rapid jump of the arc, and at least one of the above problems can be effectively overcome.

[0007] The technical solution of the present invention is as follows:

[0008] A circuit breaker includes at least an insulating housing and internal components. The internal components at least include an arc extinguishing chamber, an arc guide piece, a static contact, a moving contact, a terminal, an operating mechanism, and an arc guide piece. The arc extinguishing chamber is composed of a plurality of stacked metal arc extinguishing grid pieces. The arc guide piece is integrally arranged with the static contact. At least one magnetic yoke is arranged on the connecting conductor between the static contact and the terminal. The magnetic yoke is in a U shape or a C shape. The opening of the magnetic yoke faces the metal arc extinguishing grid pieces of the arc extinguishing chamber or / and the arc guide piece. When current flows through the connecting conductor, a magnetic field will be generated at the opening of the U-shaped or C-shaped magnetic yoke. The magnetic field acts on the metal arc extinguishing grid pieces or / and the arc guide piece. When the moving contact leaves the static contact to generate an arc, the metal arc extinguishing grid pieces or / and the arc guide piece with a magnetic field will accelerate the arc generated on the static contact to move towards the metal arc extinguishing grid pieces or / and the arc guide piece, increasing the arc deionization effect.

[0009] In this way, through the magnetic field of the magnetic yoke acting on the metal arc extinguishing grid pieces or / and the arc guide piece, the metal arc extinguishing grid pieces or / and the arc guide piece are magnetized, and have the effect of quickly attracting and extinguishing the arc. A U-shaped or C-shaped magnetic yoke is sleeved on the connecting conductor between the static contact and the terminal, and metal arc extinguishing grid pieces or / and an arc guide piece are arranged at the opening of the magnetic yoke. The metal arc extinguishing grid pieces or / and the arc guide piece form a magnetic circuit with the magnetic yoke. The metal arc extinguishing grid pieces or / and the arc guide piece are magnetized by the magnetic yoke to generate a magnetic field to quickly attract the arc, promoting the rapid jump of the arc.

[0010] In a preferred embodiment, the arc guide piece extends from the side of the static contact facing the magnetic yoke direction, and the arc guide piece is made of a magnetically conductive metal material.

[0011] In this way, the arc guide piece extending from the static contact can cooperate with the magnetic yoke to generate magnetism to quickly attract and jump the arc and improve the breaking capacity only when the material of the arc guide piece is a magnetically conductive material.

[0012] In a preferred embodiment, when the opening of the magnetic yoke faces the metal arc extinguishing grid pieces of the arc extinguishing chamber, the opening of the magnetic yoke faces the side of the first metal arc extinguishing grid piece at the uppermost end of the arc extinguishing chamber.

[0013] In this way, the opening of the yoke faces the side of the first metal arc-extinguishing grid at the top of the arc-extinguishing chamber. The opening of the yoke is the magnetic pole, and the magnetic field force is the largest. The side of the metal arc-extinguishing grid cooperates with it to have the largest magnetic area, high magnetic efficiency, and better effect of attracting the arc.

[0014] In a preferred embodiment, the arc-starting piece has at least one bend, and one end of the arc-starting piece is planar and faces the opening of the yoke.

[0015] In this way, when the planar part of the arc-striking piece faces the opening of the yoke, the planar part of the arc-striking piece cooperates with the magnetic pole at the opening of the yoke to maximize the magnetic area, high magnetic efficiency, and better effect of attracting the arc.

[0016] In a preferred embodiment, when the opening of the yoke faces the arc extinguishing chamber and the arc striking plate, the opening of the yoke faces the rear end of the arc extinguishing chamber, corresponding to the ends of at least two of the arc striking plate and the metal arc extinguishing grid.

[0017] In this way, when the opening of the yoke faces the arc extinguishing chamber and the arc striking plate, the opening of the yoke faces the rear of the arc extinguishing chamber, and can correspond to the arc striking plate and the metal arc extinguishing grid of the arc extinguishing chamber at the same time. The generated magnetic field can be applied to the arc striking plate and the metal arc extinguishing grid at the same time, thereby improving the arc striking effect and improving the breaking capacity of the circuit breaker.

[0018] In a preferred embodiment, the arc-striking piece and the stationary contact are integrated into one body by at least one of welding, riveting and crimping. When the stationary contact and the arc-striking piece are both made of magnetic conductive materials, the two are formed in one body.

[0019] In this way, the opening of the yoke faces the arc-striking piece. When current passes through the connecting conductor, the yoke will produce a magnetic field. The arc-striking piece is magnetized by the magnetic field of the yoke to generate magnetism to quickly attract the arc generated between the moving contact and the static contact when the switch is turned off, thereby accelerating the extinguishing of the arc. The material of the arc-striking piece must be a magnetic conductive material in order to be magnetized by the yoke. The static contact also plays the role of normal power supply. There are certain requirements for conductivity, especially in the case of high rated current. It is necessary to select copper that does not have a magnetic conductive effect. In order to start an arc, the static contact also needs to be electrically connected to the arc-striking piece. The one-piece static contact and arc-striking piece made of magnetic conductive material is also feasible for application in small current specifications. It has the advantages of simple process and low cost. In the case of large current specifications, the static contact part uses copper with low resistivity and the arc-striking piece made of magnetic conductive metal. The integrated design is achieved by welding, riveting, crimping and other methods, which saves costs and improves arc extinguishing ability.

[0020] In a preferred embodiment, the end shape of the opening position of the yoke is one of a straight edge, a bevel edge, an arc, and a special shape.

[0021] In the above embodiments, the inner wall of the U-shaped or C-shaped yoke and the end face at the opening position are places where magnetic field lines are dense. Through the flexible layout of the end shape, the magnetic field received by the armature is maximized, enhancing the attraction of the armature to the arc.

[0022] In a preferred embodiment, the connecting conductor surrounds the root of the yoke for at least half a turn.

[0023] In the above embodiments, the more turns the connecting conductor surrounds the U-shaped or C-shaped yoke or the longer the length the connecting conductor surrounds, the stronger the magnetic field generated by the U-shaped or C-shaped yoke. After the magnetic field of the yoke becomes stronger, the magnetic field acting on the armature is larger, and the better the arc ignition effect.

[0024] In a preferred embodiment, the U-shaped or C-shaped yoke is composed of at least one part in a split or integral form.

[0025] In the above embodiments, the U-shaped or C-shaped yoke can be an integral type of one part or a split type formed by splicing two parts, and can be set according to the specific assembly scenario.

[0026] The beneficial effects of the present invention are as follows:

[0027] In the present invention, a U-shaped or C-shaped yoke is sleeved on the connecting conductor between the static contact and the terminal. The opening of the yoke faces the arc ignition piece and / or the metal arc extinguishing grid piece of the arc extinguishing chamber. When there is current passing through the connecting conductor, the yoke is magnetized, and the arc ignition piece and / or the metal arc extinguishing grid piece of the arc extinguishing chamber are magnetized by the yoke to generate a magnetic field to quickly attract the arc, promoting the rapid jump of the arc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Partial structural schematic diagram of the existing circuit breaker;

[0030] Figure 2 For Figure 1 Waveform diagram of the relationship between current, voltage and time of the arc when the circuit breaker fails to trip;

[0031] Figure 3 Internal structural schematic diagram of the circuit breaker according to the first specific embodiment of the present invention;

[0032] Figure 4 For Figure 3Schematic diagram of the closed magnetic circuit structure formed by the middle magnetic yoke and the arc-starting piece;

[0033] Figure 5 for Figure 3 Schematic diagram of the induced magnetic field generated by the middle magnetic yoke under the influence of the static contact current;

[0034] Figure 6 for Figure 3 The waveform diagram of the relationship between the current, voltage and time of the arc when the circuit breaker fails and breaks;

[0035] Figure 7 It is a partial structural schematic diagram of a circuit breaker according to a second specific embodiment of the present invention;

[0036] Figure 8 It is a partial structural schematic diagram of a circuit breaker according to a third specific embodiment of the present invention;

[0037] Fig. 9 This is a schematic diagram of a closed magnetic circuit structure formed by a magnetic yoke and a metal arc-extinguishing grid of a circuit breaker according to a fourth specific embodiment of the present invention;

[0038] Fig.10 for Fig. 9 Schematic diagram of the induced magnetic field generated by the middle magnetic yoke under the influence of the static contact current;

[0039] Fig.11 for Fig.10 Schematic diagram of magnetic lines of force formed by the middle magnetic yoke;

[0040] Fig.12 for Fig. 9 Schematic diagram of magnetic force lines distribution of closed magnetic circuit formed by middle magnetic yoke and metal arc extinguishing grid;

[0041] Fig.13 It is a partial structural schematic diagram of a circuit breaker according to a sixth specific embodiment of the present invention;

[0042] Fig.14 It is a partial structural schematic diagram of a circuit breaker according to a seventh specific embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments.

[0044] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0045] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] Embodiment 1

[0047] Please refer to Figures 3 to 6 , a specific embodiment of the present invention provides a circuit breaker, which at least includes an insulating housing 10 and internal components. The internal components at least include an arc extinguishing chamber 80, a static contact 30, a moving contact 40, a terminal 50, an operating mechanism 20, and an arc guiding piece 301. The terminals 50 are arranged at both ends in the length direction of the circuit breaker. One terminal 50 is connected to the static contact 30 through a connecting conductor 91, and the other terminal 50 is connected to the moving contact 40. The arc extinguishing chamber 80 is formed by arranging multiple metal arc extinguishing grid pieces in sequence. At least one magnetic yoke 101 is arranged on the connecting conductor 91. The magnetic yoke 101 is in a U shape or a C shape. The arc guiding piece 301 extends from the side of the static contact 30 facing the magnetic yoke 101. The arc guiding piece is made of a magnetically conductive metal material, and the opening of the magnetic yoke 101 faces the arc guiding piece 301.

[0048] The magnetic yoke 101 acts on the arc guiding piece 301 to generate a magnetic field, magnetize the arc guiding piece, and has the effect of quickly attracting and extinguishing the arc. The opening of the magnetic yoke 101 faces the arc guiding piece, so that the arc guiding piece and the magnetic yoke form a magnetic circuit. The arc guiding piece is magnetized by the magnetic yoke to generate a magnetic field to quickly attract the arc, prompting the arc to quickly jump. When the connecting conductor conducts current, a magnetic field will be generated at the opening of the U-shaped or C-shaped magnetic yoke. The magnetic field acts on the arc guiding piece. When the moving contact leaves the static contact to generate an arc, the arc guiding piece with a magnetic field accelerates the arc generated on the static contact towards the arc guiding piece, increasing the arc deionization effect.

[0049] In this embodiment, the arc guiding piece 301 extends forward from the conductor where the alloy contact is arranged on the static contact 30. The arc guiding piece 301 is made of a magnetically conductive metal material and is welded to the static contact 30 with good electrical conductivity. In other embodiments, the arc guiding piece 301 can also be electrically connected to the static contact by riveting, pressing, etc. In a small current circuit breaker, the static contact and the arc guiding piece can also be integrally formed, which requires that both the static contact and the arc guiding piece are made of a magnetically conductive metal material. The arc extinguishing chamber 80 is arranged below the arc guiding piece 301 and adjacent to the arc guiding piece 301.

[0050] Please refer to Figure 5The present invention arranges a yoke 101 on the connecting conductor 91 between the connecting terminal 50 and the stationary contact 30. The yoke 101 generates a magnetic field on the arc-striking piece 301. When current flows through the connecting conductor 91, the yoke 101 is magnetized to generate a magnetic field. The magnetic field magnetizes the arc-striking piece 301 and generates a suction force on the arc. As a result, the arc can be quickly transferred to the arc-striking piece 301 under the suction force of the arc-striking piece 301, and then enter the arc extinguishing chamber 80, which speeds up the separation of the arc from the moving contact and the stationary contact, thereby greatly improving the breaking capacity of the circuit breaker.

[0051] Please refer to Figure 6 After a yoke 101 is added to the connecting conductor between the static contact 30 and the terminal 50, the time that the arc stays on the moving contact 40 and the static contact 30 is t0-t1. Compared with the existing circuit breaker, the time that the arc stays on the moving contact and the static contact is significantly shortened. It can be seen that a yoke 101 is sleeved on the connecting conductor 91 between the static contact 30 and the terminal 50, and an arc-starting piece is arranged at the opening position of the yoke 101, which accelerates the arc jumping to the arc-starting piece, shortens the breaking time of the circuit breaker, and makes the arc leave the moving contact 40 and the static contact 30 as soon as possible. On the one hand, it reduces the arc erosion of the moving contact and the static contact, and on the other hand, it accelerates the arc jumping and arc extinguishing time, greatly improving the short-circuit breaking capacity of the circuit breaker.

[0052] Embodiment 2

[0053] Please refer to Figure 7 As shown, the present invention also provides a circuit breaker of a specific embodiment. The difference between this embodiment and the first embodiment is that the armature is an arc-starting piece 301 made of magnetic conductive material extending from the rear of the conductor on which the alloy contact is arranged on the static contact 30. The other structures are the same as those in the first embodiment and will not be repeated here.

[0054] Embodiment 3

[0055] Please refer to Figure 8 As shown, the present invention also provides another specific embodiment of a circuit breaker. The difference between this embodiment and the first embodiment is that an arc-striking portion 302 is provided at the end of the static contact, and the arc-striking portion 302 is made of non-magnetic material. One end of the arc-striking piece 301 in this embodiment is adjacent to the arc-striking portion 302, and the arc-striking piece 301 is made of magnetic material. The arc-striking piece 301 extends from below the alloy contact of the static contact 30 and adjacent to the arc-striking portion 302 to the front of the static contact. The front of the arc-striking piece 301 extends into the opening of the yoke 101. The yoke 101 generates a magnetic field for the arc-striking piece 301. When current flows through the connecting conductor 91, the yoke 101 is magnetized to generate a magnetic field. The magnetic field magnetizes the arc-striking piece 301 to generate suction force on the arc. The arc can be quickly jumped to the arc-striking piece 301 under the suction force of the arc-striking piece. The other structures of the circuit breaker of this embodiment are the same as those of the first embodiment, and are not repeated here.

[0056] In other embodiments, the arc striking piece 301 made of a magnetic conductive material may also be adjacent to the arc striking portion 302 made of a non-magnetic conductive material or integrally provided with the arc striking portion 302.

[0057] Embodiment Four

[0058] Please refer to Figures 9 to 12 , the present invention provides a circuit breaker of a specific embodiment, which is different from Embodiment One in that the opening of the magnetic yoke 101 faces the side of the first metal arc extinguishing grid piece 801 at the uppermost end of the arc extinguishing chamber 80, and the magnetic yoke 101 generates a magnetic field on the metal arc extinguishing grid piece 801. When current flows through the connecting conductor, a magnetic field will be generated at the opening of the U-shaped or C-shaped magnetic yoke, and the magnetic field acts on the metal arc extinguishing grid piece 801. When an arc is generated when the moving contact leaves the static contact, the metal arc extinguishing grid piece with the magnetic field accelerates the arc generated on the static contact towards the metal arc extinguishing grid piece, increasing the arc deionization effect.

[0059] Please continue to refer to Fig.10 , in the present invention, a magnetic yoke 101 is sleeved on the connecting conductor 91 between the terminal 50 and the static contact 30. The magnetic yoke 101 generates a magnetic field on the metal arc extinguishing grid piece 801. When current flows through the connecting conductor 91, the magnetic yoke 101 is magnetized to generate a magnetic field, and the magnetic field magnetizes the metal arc extinguishing grid piece 801 to generate a suction force on the arc. Thus, the arc can quickly jump to the metal arc extinguishing grid piece 801 under the suction force of the metal arc extinguishing grid piece 801, and then enter the arc extinguishing chamber 80, accelerating the separation of the arc from the moving contact and the static contact, and greatly improving the breaking capacity of the circuit breaker.

[0060] Please continue to refer to Fig.11 and Fig.12 , in the present invention, a magnetic yoke 101 is sleeved on the connecting conductor 91 between the terminal 50 and the static contact 30. The magnetic yoke 101 is U-shaped or C-shaped. When current passes through the connecting conductor 91, the magnetic yoke 101 will be magnetized by the induced magnetic field generated on the connecting conductor 91, making the magnetic yoke 101 magnetic. A magnetic pole will be formed at the opening of the magnetic yoke 101, and the magnetic force lines will gather here. By arranging an armature at the opening position of the magnetic yoke 101 to cooperate with it, the magnetic force lines pass through the armature, making the armature also magnetic. Utilizing the magnetic suction effect of the armature on the arc accelerates the separation of the arc from the moving contact and the static contact, greatly shortening the arcing time of the circuit breaker and greatly improving the breaking capacity.

[0061] Embodiment Five

[0062] Please refer to Fig.13, the present invention provides a circuit breaker of a specific embodiment, which is different from the first embodiment in that a bent section is provided at one end of the arc guide piece 301 close to the magnetic yoke 101, and the opening of the magnetic yoke 101 faces the bent section of the arc guide piece 301. The magnetic yoke 101 generates a magnetic field on the arc guide piece 301. In this embodiment, the arc guide piece 301 is an arc guide piece 301 made of a magnetic conductive material extending from behind the conductor where the alloy contact is provided on the static contact 30. Both ends of the arc guide piece 301 have bends. One end of the arc guide piece 301 bends downward from behind the conductor where the alloy contact is provided and then extends backward, and bends downward when reaching the magnetic yoke 101. The arc extinguishing chamber 80 is arranged below the arc guide piece 301 and adjacent to the arc guide piece 301.

[0063] Embodiment Six

[0064] Please refer to Fig.14 , a circuit breaker of a specific embodiment provided by the present invention is different from the first embodiment in that the opening of the magnetic yoke 101 faces the arc extinguishing chamber and the arc guide piece 301, that is, the opening of the magnetic yoke 101 faces the rear end of the arc extinguishing chamber and the end of the arc guide piece. The magnetic yoke 101 generates a magnetic field on the arc guide piece 301 and the metal arc extinguishing grid piece. In this embodiment, the arc guide piece is an arc guide piece 301 made of a magnetic conductive material extending from behind the conductor where the alloy contact is provided on the static contact 30. Different from the fifth embodiment, the opening of the magnetic yoke 101 faces both the arc guide piece 310 and the metal arc extinguishing grid piece 801. When there is current passing through the connecting conductor 91 between the static contact 30 and the terminal 50, a magnetic field will be generated at the opening of the U-shaped or C-shaped magnetic yoke. The magnetic field acts on the metal arc extinguishing grid piece and the arc guide piece. When the moving contact leaves the static contact and an arc is generated, the metal arc extinguishing grid piece and the arc guide piece with the magnetic field accelerate the arc generated on the static contact towards the metal arc extinguishing grid piece and the arc guide piece, increasing the arc deionization effect. That is, when there is current passing through the connecting conductor 91 between the static contact 30 and the terminal 50, the magnetic yoke 101 will generate an induced magnetic field. The opening of the magnetic yoke 101 is the N / S magnetic pole. The magnetic force lines pass through the armature and magnetize the arc guide piece 310 and the metal arc extinguishing grid piece 801, making them magnetic, and quickly attracting the arc into the arc extinguishing chamber for arc extinguishing operation, improving the arc extinguishing effect.

[0065] The present invention can be implemented in other specific forms without departing from its spirit and essential features. The current embodiments are regarded as exemplary in all aspects rather than restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalents of the claims are thus included in the scope of the present invention.

Claims

1. A circuit breaker, comprising at least an insulating housing and internal components, wherein the internal components at least include an arc extinguishing chamber, a static contact, a moving contact, a terminal, an operating mechanism, and an arc striking piece, wherein the arc extinguishing chamber is composed of a plurality of metal arc extinguishing grids stacked together, and the arc striking piece is integrated with the static contact, characterized in that: At least one magnetic yoke is provided on the connecting conductor between the static contact and the terminal. The magnetic yoke is U-shaped or C-shaped, and the opening of the magnetic yoke faces the metal arc extinguishing grid or / and the arc initiating piece of the arc extinguishing chamber.

2. The circuit breaker according to claim 1, characterized in that: The arc initiating piece extends from the side of the static contact facing the magnetic yoke, and the arc initiating piece is made of a magnetically conductive metal material.

3. The circuit breaker according to claim 1, characterized in that: When the opening of the magnetic yoke faces the metal arc extinguishing grid of the arc extinguishing chamber, the opening of the magnetic yoke faces the side of the first metal arc extinguishing grid at the uppermost end of the arc extinguishing chamber.

4. The circuit breaker according to claim 1, characterized in that: The arc initiating piece has at least one bend, and one end of the arc initiating piece is planar and faces the opening of the magnetic yoke.

5. The circuit breaker according to claim 1, characterized in that: When the opening of the magnetic yoke faces the arc extinguishing chamber and the arc initiating piece, the opening of the magnetic yoke faces the rear end of the arc extinguishing chamber, corresponding to the ends of at least two of the arc initiating piece and the metal arc extinguishing grid.

6. The circuit breaker according to claim 1, characterized in that: The arc initiating piece and the static contact are integrally provided by at least one of welding, riveting, and pressing. When both the static contact and the arc initiating piece are made of magnetically conductive materials, they are integrally formed.

7. The circuit breaker according to claim 1, characterized in that: The end shape at the opening position of the magnetic yoke is one of a straight edge, an inclined edge, an arc, and a special shape.

8. The circuit breaker according to claim 1, characterized in that: The connecting conductor surrounds the root of the magnetic yoke for at least half a turn.

9. The circuit breaker according to claim 1, characterized in that: The U-shaped or C-shaped magnetic yoke is composed of at least one part, either separated or integrated.

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