WO2023051556A1

WO2023051556A1 - Arc extinguishing apparatus and circuit breaker including arc extinguishing apparatus

Info

Publication number: WO2023051556A1
Application number: PCT/CN2022/121886
Authority: WO
Inventors: Haitao Sun; Yibo LI; Pengyu ZHANG
Original assignee: Schneider Electric Industries Sas
Priority date: 2021-09-29
Filing date: 2022-09-27
Publication date: 2023-04-06
Also published as: CN216450582U

Abstract

An arc extinguishing apparatus (100) and a circuit breaker (200) comprising the same. The arc extinguishing apparatus (100) comprises: a stationary contact (10), a movable contact (20), an arc chute assembly (30), a first side plate (50), a second side plate (60) and a gas-producing assembly (40). The stationary contact (10) includes a stationary contact point (104), while the movable contact (20) consists of a movable contact point (202) adapted to mate with the stationary contact point (104). The arc chute assembly (30) is positioned above the stationary contact (10) and includes stacked arc chutes (302), wherein each arc chute (302) includes a base (301), a first arm (304) and a second arm (306), wherein the first and second arms (304,306) extend along two opposite sides of the base (301) and partially surround the stationary contact point (104). The first and second side plates (50,60)are made of insulating materials and coupled at two sides of the arc chute assembly (30) to fix the stacked arc chutes (302). The gas-producing assembly (40) includes a first clamping portion (402) and a second clamping portion (404) made of insulating materials, wherein the first clamping portion (402) clamps and isolates the end of the respective first arm (304) and the second clamping portion (404) clamps and isolates the end of the respective second arm (306).The arc extinguishing apparatus (100) can enhance the arc extinguishing performance by a simple structure and implement AC/DC universal purpose.

Description

ARC EXTINGUISHING APPARATUS AND CIRCUIT BREAKER INCLUDING ARC EXTINGUISHING APPARATUS

FIELD

The present disclosure relates to the field of electrical protection devices, and more specifically, to an arc extinguishing apparatus and a circuit breaker including arc extinguishing apparatus.

BACKGROUND

Circuit breaker, as an important part of power distribution equipment, mainly connects and disconnects protection lines in power grids, to protect electrical devices against overvoltage, short circuit and the like. The circuit breaker breaks the currents mainly by an arc extinguishing apparatus mounted in the circuit breaker.

When the existing circuit breaker breaks fault currents and critical load currents, arcs have trouble entering an arc extinguishing chamber inside the arc extinguishing apparatus and thus can hardly be extinguished. In particular, when applying to DC systems, e.g., DC photovoltaic systems, the circuit breaker is required to break currents within the rated current range. However, the magnetic blow force is insufficient in case of small currents, and it is impossible or hard for the arcs to enter the arc extinguishing chamber as a result. The arcs that do not enter the arc extinguishing chamber may continue to burn, which may easily damage product performance.

Hence, an improved solution that can improve the arc extinguishing performance is in need.

SUMMARY

An object of the present disclosure is to provide an arc extinguishing apparatus to at least partly solve the above and other potential problems.

According to a first aspect, embodiments of the present disclosure provide an arc extinguishing apparatus. The arc extinguishing apparatus comprises: a stationary contact, a movable contact, an arc chute assembly, a first side plate, a second side plate and a gas-producing assembly. The stationary contact includes a stationary contact point, while the movable contact consists of a movable contact point adapted to mate with the stationary contact point. The arc chute assembly is positioned above the stationary contact and includes stacked arc chutes, wherein each arc chute includes a base, a first arm and a second arm, wherein the first and second arms extend along two opposite sides of the base and partially surround the stationary contact point. The first and second side plates are made of insulating materials and coupled at two sides of the arc chute assembly, to fixate the stacked arc chutes. The gas-producing assembly includes a first clamping portion and a second clamping port made of insulating materials, wherein the first clamping portion clamps and isolates the end of the respective first arm and the second clamping portion clamps and isolates the end of the respective second arm.

In this way, the arc extinguishing apparatus in use can accelerate the rate of arcs entering the arc extinguishing chamber, prevent the arc extinguishing apparatus from reverting to the ends of the first and second arms of the arc chutes and further extinguish the arc more rapidly.

In some embodiments, the first clamping portion includes a plurality of first teeth arranged in a longitudinal direction and a first baffle disposed adjacent to the plurality of first teeth. The second clamping portion includes: a plurality of second teeth arranged in a longitudinal direction; and a second baffle disposed adjacent to the plurality of second teeth; wherein respective ones of the first teeth, the first baffle and the first side plate isolate an end of a respective one of the first arm; and respective ones of the second teeth, the second baffle and the second side plate isolate an end of a respective one of the second arm.

In the above embodiments, for insulation purpose, the ends of the first and second arms of the arc chutes are clamped by the first clamping portion and the second clamping portion, to protect the arc from a secondary breakdown and avoid re-burning of the arc at this position.

In some embodiments, the first clamping portion includes a plurality of first grooves arranged in longitudinal direction, respectively mating with an end of a respective one of the first arm and isolating an end of the first arm. The second clamping portion includes a plurality of second grooves arranged in longitudinal direction, respectively mating with an end of a respective one of the second arm and isolating an end of the second arm.

In the above embodiments, the ends of the first and second arms of the arc chutes are insulated by the grooves provided in the first and second clamping portions, to protect the arc from a secondary breakdown and avoid re-burning of the arc at this position.

In some embodiments, the arc extinguishing apparatus also includes a movable arc striking sheet including a connecting portion and a bending portion, wherein the connecting portion is coupled to the first side plate and the second side plate; the bending portion extends in a direction away from the stationary contact; a distal end of the bending portion gets close to the movable contact when the movable contact is at a cutoff position where it separates from the stationary contact.

In the above embodiments, when a bending portion that bends upward is arranged on the movable arc striking sheet, the longitudinal length of the arc extinguishing chamber increases, to lengthen the arc and facilitate the arc extinguishing process.

In some embodiments, the stacked arc chutes are arranged in a fan shape and an extended surface of respective ones of the arc chutes intersects at a rotation axis of the movable contact.

In the above embodiments, the stacked arc chutes are arranged in a fan shape and an extended surface of respective ones of the arc chutes is enabled to intersect at a rotation axis of the movable contact, the arcs may be more easily introduced into the arc extinguishing chamber.

In some embodiments, the movable contact includes a flat surface, and the flat surface is in the same plane with respective ones of the arc chutes successively during movement of the movable contact.

In the above embodiments, the flat surface is configured to be in the same plane with respective ones of the arc chutes successively, the resistance against the arc transfer may be reduced and the arc may be more rapidly introduced into the arc extinguishing chamber.

In some embodiments, the stationary contact also includes a bending structure disposed at one end, and the stationary contact is positioned on a surface of the bending structure facing the arc chutes.

In the above embodiments, the stationary contact includes a bending structure in which an enhanced magnetic sheet is received. In addition, the position of the stationary contact is adapted to mate with the movable contact.

In some embodiments, the arc extinguishing apparatus further comprises an enhanced magnetic sheet disposed at an inner side of the bending structure.

In the above embodiments, when the enhanced magnetic sheet is disposed in the stationary contact, the magnetic blow-out effect can be boosted and the arc is more rapidly transferred into the arc extinguishing chamber.

In some embodiments, the stationary contact also includes a stationary arc striking sheet consisting of a first portion and a second portion, wherein the first portion is positioned on the surface of the bending structure and close to the stationary contact point, and the second portion bends in a direction from the first portion towards the arc chutes and is narrowed.

In the above embodiments, it may assist introducing the arc into the arc extinguishing chamber if one end of the stationary arc striking sheet is set to bend towards the arc chutes.

In some embodiments, projections of respective ones of the arc chutes on the surface of the bending structure partially overlap with the stationary arc striking sheet.

In the above embodiments, when the projections of the arc chutes on the surface of the bending structure partially overlap with the stationary arc striking sheet, a magnetic field therebetween is enhanced and the arc is more rapidly introduced into the arc extinguishing chamber.

In some embodiments, space areas are formed between the first arm and the second arm and between the first clamping portion and the second clamping portion; and the movable contact is adapted to mate with the stationary contact within the space areas.

In the above embodiments, the above space areas are provided to prevent the arc chutes, the first clamping portion and the second clamping portion from hindering the acts of the movable contact.

In some embodiments, the stationary contact is surrounded by the first arm, the second arm and the gas-producing assembly.

In the above embodiments, the first and second arms surround the stationary contact point to enhance the strength of the magnetic field near the stationary contact point, increase the magnetic blow force and accelerate the rate of arcs entering the arc extinguishing chamber.

In some embodiments, respective ones of the arc chutes have U-shaped, V-shaped or W-shaped structure.

In the above embodiments, the arc chutes are configured to have U-shaped, V-shaped or W-shaped structure, to enhance the strength of the magnetic field near the stationary contact point and accelerate the rate of arcs entering the arc extinguishing chamber.

Embodiments of the present disclosure provide an improved arc extinguishing apparatus, which can boost the arc extinguishing performance via a simple structure and implement the AC/DC universal purpose.

According to a second aspect, embodiments of the present disclosure also provide a circuit breaker comprising the arc extinguishing apparatus according to the first aspect of the present disclosure.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1A illustrates an exploded view of the arc extinguishing apparatus in accordance with one embodiment of the present disclosure;

Fig. 1B illustrates a stereogram of the arc extinguishing apparatus in accordance with one embodiment of the present disclosure;

Fig. 2A illustrates a stereogram of the stationary contact in accordance with one embodiment of the present disclosure;

Fig. 2B illustrates a top view of the stationary contact in accordance with one embodiment of the present disclosure;

Fig. 3A illustrates a stereogram of the enhanced magnetic sheet box in accordance with one embodiment of the present disclosure;

Fig. 3B illustrates a top view of the enhanced magnetic sheet box in accordance with one embodiment of the present disclosure;

Fig. 4 illustrates a stereogram of the enhanced magnetic sheet in accordance with one embodiment of the present disclosure;

Fig. 5A illustrates a stereogram of the movable contact in accordance with one embodiment of the present disclosure;

Fig. 5B illustrates a lateral view of the movable contact in accordance with one embodiment of the present disclosure;

Fig. 6A illustrates a stereogram of the arc extinguishing chamber in accordance with one embodiment of the present disclosure;

Fig. 6B illustrates a front view of the arc extinguishing chamber in accordance with one embodiment of the present disclosure;

Fig. 7A illustrates a stereogram of the first arc chute in accordance with one embodiment of the present disclosure;

Fig. 7B illustrates a front view of the first arc chute in accordance with one embodiment of the present disclosure;

Fig. 8A illustrates a stereogram of the second arc chute in accordance with one embodiment of the present disclosure;

Fig. 8B illustrates a front view of the second arc chute in accordance with one embodiment of the present disclosure;

Fig. 9A illustrates a stereogram of the movable arc striking sheet in accordance with one embodiment of the present disclosure;

Fig. 9B illustrates a top view of the movable arc striking sheet in accordance with one embodiment of the present disclosure;

Fig. 10A illustrates a stereogram of the gas-producing assembly in accordance with one embodiment of the present disclosure;

Fig. 10B illustrates a front view of the gas-producing assembly in accordance with one embodiment of the present disclosure;

Fig. 11 illustrates a local stereogram of the arc extinguisher in accordance with one embodiment of the present disclosure;

Fig. 12 illustrates a local stereogram of the circuit breaker in accordance with one embodiment of the present disclosure.

In each drawing, same or corresponding reference signs indicate same or corresponding composites.

DETAILED DESCRIPTION OF EMBODIMENTS

Principles of the present disclosure are to be explained with reference to various example embodiments shown in the drawings. It should be appreciated that description of those embodiments is merely to enable those skilled in the art to better understand and further implement the present disclosure and is not intended for limiting the scope disclosed herein in any manners. It should be noted similar or same reference signs can be used in the drawings where feasible, and similar or same reference signs can represent similar or same functions. Those skilled in the art will easily understand from the following description that alternative embodiments of the structure and/or method described in the text can be adopted without deviating from the principles of the invention described herein.

As used herein, the term “includes” and its variants are to be read as open-ended terms that mean “includes, but is not limited to. ” Unless the context clearly indicates otherwise, the term “or” is to be read as “and/or” . The term “based on” is to be read as “based at least in part on. ” The terms “one example embodiment” and “one embodiment” are to be read as “at least one example embodiment. ” The term “a further embodiment” is to be read as “at least a further embodiment. ” The terms “first” , “second” and so on can refer to same of different objects.

As stated above, the circuit breaker breaks a current mainly by an arc extinguishing apparatus mounted in the circuit breaker. An existing arc extinguishing apparatus cuts the arc into more segments primarily by adding the number of arc chutes, so as to increase the arc voltage and extinguish the arc rapidly. Four different types of arc chutes are provided, including top arc chutes, upper arc chutes, intermediate arc chutes and bottom arc chutes. The respective arc chutes differ from one another in length, thickness and quantity. This solution involves a rather complicated structure and multiple components, which is inconvenient for mounting and maintenance.

The arcs are produced mainly because contacts of the switch device per se and media surrounding the contacts contain massive ionizable electrons. When a sufficient external voltage is applied between the broken contacts and the circuit current also reaches the minimum arc-producing level, strong ionization may occur, thereby forming arcs. The arcs may erode the contacts and further impact the connection effect of the contacts. Accordingly, it is expected to transfer the arcs from the contacts and extinguish the arcs as quickly as possible, to effectively lower the damage to the contacts and fulfill the purpose of extending the life service of the circuit breaker. In addition, it is usually required to extinguish the arcs in an arc extinguishing chamber. As mentioned above, arcs may have troubles entering the arc extinguishing chamber inside the arc extinguishing apparatus. For this, improvements may be required. Therefore, a modified solution for improving the arc extinguishing performance is in need.

Embodiments of the present disclosure provide an improved arc extinguishing apparatus. In some embodiments of the present disclosure, the arc extinguishing apparatus includes a stationary contact, a movable contact, an arc chute assembly, a first side plate, a second side plate and a gas-producing assembly. The stationary contact includes a stationary contact point, while the movable contact consists of a movable contact point adapted to mate with the stationary contact point. The arc chute assembly is positioned above the stationary contact and includes stacked arc chutes, wherein each arc chute includes a base, a first arm and a second arm, wherein the first and second arms extend along two opposite sides of the base and partially surround the stationary contact point. The arc extinguishing apparatus also includes the first and second side plates made of insulating materials and coupled at two sides of the arc chute assembly, to fixate the stacked arc chutes. The first and second side plates and the arc chute assembly constitute an arc extinguishing chamber. The first and second arms partially surround the stationary contact point to enhance the magnetic field near the contact point, thereby increasing the magnetic blow force and facilitating the transfer of the arc to the arc extinguishing chamber. In the magnetic field, the arcs may generate electromagnetic forces, i.e., Lorentz force, which may be applied to the arc extinguishing process. The electromagnetic force is employed to pull the arc into the arc extinguishing chamber to lengthen the arc. The entry of the arc into the arc extinguishing chamber and the lengthening of the arc are conducive to arc cooling and deionization. The gas-producing assembly includes a first clamping portion and a second clamping port made of insulating materials, wherein the first clamping portion clamps and isolates the end of the respective first arm and the second clamping portion clamps and isolates the end of the respective second arm. The gas-producing assembly clamps and isolates the ends of the first and second arms, such that the ends are insulated from the surrounding air. Thus, the nearby air may be protected from a secondary breakdown, which secondary breakdown may generate arcs again. The apparatus can achieve improved arc extinguishing effects via a simple structure and further implement AC/DC universal purpose.

The arc extinguishing apparatus in accordance with example embodiments of the present disclosure is described in details below with reference to Figs. 1A to 12. It is to be understood that the embodiments below explain the spirit and principle of the present disclosure by taking the arc extinguishing apparatus having exemplary structure and shape as the example. However, the scope of the present disclosure is not limited to this. Instead, the arc extinguishing apparatus having other structures and shapes may also be included.

First of all, an arc extinguishing apparatus 100 in accordance with one embodiment of the present disclosure is described with reference to Figs. 1A and 1B. Fig. 1A illustrates an exploded view of the arc extinguishing apparatus in accordance with one embodiment of the present disclosure, and Fig. 1B shows a stereogram of the arc extinguishing apparatus in accordance with one embodiment of the present disclosure. In some embodiments, the arc extinguishing apparatus 100 in general includes a stationary contact 10, a movable contact 20, an arc chute assembly 30, a first side plate 50, a second side plate 60 and a gas-producing assembly 40 according to Figs. 1A and 1B.

As illustrated, in some embodiments, the stationary contact 10 is positioned at a lower part of the arc extinguishing apparatus 100. In some embodiments, the stationary contact 10 includes a stationary contact point 104. In some embodiments, the movable contact 20 is arranged adjacent to the stationary contact 10 and includes a movable contact point 202 (see Fig. 5A) , which movable contact point 202 is adapted to mate with the stationary contact point 104. In some embodiments, the stationary contact point 104 may be made of silver or silver-copper alloy. In some embodiments, the movable contact point 202 may be made of silver or silver-copper alloy.

In some embodiments, the arc chute assembly 30 may be positioned above the stationary contact 10 and includes stacked arc chutes 302. In some embodiments, each arc chute 302 may consist of a base 301 (see Fig. 7A) , a first arm 304 and a second arm 306, wherein the first arm 304 and the second arm 306 extend along two opposite sides of the base 301 and partially surround the stationary contact point 104. In some embodiments, the first side plate 50 and the second side plate 60 may be made of insulating materials and coupled at two sides of the arc chute assembly 30, to secure the stacked arc chutes 302. An arc extinguishing chamber is formed by the arc chute assembly 30, the first side plate 50 and the second side plate 60. In some embodiments, a gas-producing assembly 40 is disposed at a position above the stationary contact 10 and opposing to the arc chute assembly 30. The gas-producing assembly 40 may include a first clamping portion 402 and a second clamping portion 404 made of insulating materials. The first clamping portion 402 clamps and isolates the ends of the respective first arm 304. In some embodiments, the first clamping portion 402 at least partly clamps and isolates the ends of the respective first arm 304. In other words, the end is physically isolated, to reduce a contact area between the end of the first arm 304 and the air. The second clamping portion 404 clamps and isolates the ends of the respective second arm 306. In some embodiments, the second clamping portion 404 at least partly clamps and isolates the ends of the respective second arm 306, to reduce the contact area between the end of the second arm 306 and the air. In some embodiments, the first clamping portion 402 completely clamps and isolates the end of the respective first arm 304, i.e., the surrounding of the end of the first arm 304 makes no contact with air; the second clamping portion 404 completely clamps and isolates the end of the respective second arm 306, i.e., the surrounding of the end of the second arm 306 makes no contact with air.

In this way, the ends of the respective first arm 304/second arm 306 are at least partly clamped and isolated by the first clamping portion 402 and/or the second clamping portion 404, such that the arc extinguishing apparatus 100 in use can accelerate the rate of arcs entering the arc extinguishing chamber composed of the arc chute assembly 30, the first side plate 50 and the second side plate 60. The arcs are extinguished rapidly and the arc extinguishing apparatus is prevented from reverting to the ends of the first and second arms of the arc chutes and burning again. Moreover, when the ends of the respective first arm 304/second arm 306 are completely clamped and isolated by the first clamping portion 402 and/or the second clamping portion 404, the arcs are extinguished more rapidly and prevented from burning again.

The stationary contact 10 is further described below with reference to Figs. 2A and 2B. As shown in Fig. 2A, in some embodiments, the stationary contact 10 has a bending structure 102. In some embodiments, the stationary contact 10 also includes other structures in addition to the bending structure 102. The bending structure 102 may alter the direction of the currents flowing in the stationary contact 10, to increase an electric force applied to the arcs and facilitate the transfer of arcs.

In some embodiments, the stationary contact 104 is positioned on a surface 110 of the bending structure 102 facing towards the arc chute 302. In some embodiments, in addition to the above position, the stationary contact 104 also may be disposed at other suitable positions as required. In some embodiments, the bending structure 102 may be provided at its inner side with an enhanced magnetic sheet box 114 (see Fig. 1A) . In some embodiments, an enhanced magnetic sheet is received in the enhanced magnetic sheet box 114. Arcs are generated at the breaking moment of the circuit breaker, i.e., a moment when the movable contact 20 and the stationary contact 10 separate from each other. The enhanced magnetic sheet may enhance the strength of the magnetic field within the surrounding space. As the strength of the magnetic field grows, the Lorentz force experienced by the arc would also increase correspondingly. The Lorentz force pulls the arc towards the arc extinguishing chamber. In this way, the magnetic blow-out effect can be boosted, i.e., the arc is guided to the arc extinguishing chamber by means of the electromagnetic force, to accelerate the arc extinguishing process. The arc extinguishing chamber consists of the arc chute assembly 30, the first side plate 50 and the second side plate 60. In some embodiments, the arc chutes of the arc chute assembly 30 are made of metals. The arc is segmented into a plurality of burning short arcs using the arc chutes 302. Each short arc has an arc voltage at about tens of volts, e.g., 30 to 50 volts. The arc voltage usually depends on an interval of the arc chutes 302 that determines the length to which the arc is segmented. The heat conduction of the arc chutes 302 may enhance the cooling effect of the arc, rapidly export the heat inside the arc and reduce the temperature of the arc, thereby slowing down the moving speed of ions, accelerating the recombination rate and further extinguishing the arc. In some embodiments, the metal chutes may be made of steel because the ferromagnetic property of the steel may advantageously attract the arc and keep the arc inside the stacked arc chutes 302. At the initial phase, the arc is introduced into the arc chute assembly 30 via a stationary arc striking sheet. Afterwards, the electromagnetic force generated by the current loop transports the arc into the arc chutes 302.

In this way, the bending structure 102 facilitates the transfer of arc into the arc extinguishing chamber. In addition, the arc is segmented and cooled down using the arc chutes 302, to accelerate the arc extinguishing process.

In some embodiments, the stationary contact 10 also includes a stationary arc striking sheet 105 consisting of a first portion 106 and a second portion 108. The first portion 106 is positioned on the surface 110 of the bending structure 102 and close to the stationary contact point 104. The second portion 108 is bent in a direction from the first portion 106 to the arc chutes 302 and further narrowed. In the embodiments shown by Figs. 2A and 2B, the second portion 108 is in a shape of trapezoid. Embodiments of the present disclosure are not limited to this and the second portion 108 also may have other shapes, e.g., rectangle, or a combination of rectangle and other shapes, such as circle and ellipse etc. One end of the stationary arc striking sheet 105 is configured to bend towards the arc chutes 302 to facilitate introducing the arc into the arc extinguishing chamber. According to Figs. 2A and 2B, the stationary contact point 104 is in the shape of cuboid. Embodiments of the present disclosure are not limited to this, and sheet-like structures in circular, elliptical or other polygonal shape may also be used. In some embodiments, the stationary arc striking sheet 105 is spaced apart from the stationary contact point 104 by a given distance, e.g., greater than 0 and smaller than 2 millimeters. The above distance is set to facilitate introducing the arc generated between the stationary contact point 104 and the movable contact point 202 via the stationary arc striking sheet 105 into the arc extinguishing chamber, i.e., into a space delimited by the arc chute assembly 30, the first side plate 50 and the second side plate 60.

Accordingly, one end of the stationary arc striking sheet 105 is configured to be bent towards the arc chutes 302, it assists introducing the arc into the arc extinguishing chamber.

The enhanced magnetic sheet box is to be described with reference to Figs. 3A and 3B. Fig. 3A illustrates a stereogram of the enhanced magnetic sheet box 114 in accordance with one embodiment of the present disclosure, and Fig. 3B shows a top view of the enhanced magnetic sheet box in accordance with one embodiment of the present disclosure. As shown in Figs. 3A and 3B, the enhanced magnetic sheet box 114 includes a box cover portion 118 and a box body portion 116 having an accommodating space 120 for receiving the enhanced magnetic sheet 112 (see Fig. 4) . In some embodiments, the enhanced magnetic sheet box 114 is made of insulating materials, such as plastic. The enhanced magnetic sheet box 114 is not restricted to the embodiments shown in Figs. 3A and 3B and may further have multiple variations. An enhanced magnetic sheet box 114 is feasible as long as it can insulate the enhanced magnetic sheet 112 from the stationary contact 10 and stably fixate the enhanced magnetic sheet 112.

The enhanced magnetic sheet 112 is described below with reference to Fig. 4, which illustrates a stereogram of the enhanced magnetic sheet 112 in accordance with one embodiment of the present disclosure. As shown, the enhanced magnetic sheet 112 is in a cuboidal shape. In some embodiments, the enhanced magnetic sheet 112 is made of ingot iron. In some embodiments, the enhanced magnetic sheet 112 is made of silicon steel sheet. Arcs are generated at the breaking moment of the circuit breaker, i.e., a moment when the movable contact 20 and the stationary contact 10 separate from each other. The enhanced magnetic sheet 112 may enhance the strength of the magnetic field within the surrounding space. As the strength of the magnetic field grows, the Lorentz force experienced by the arc would also increase correspondingly. The Lorentz force pulls the arc towards the arc extinguishing chamber, to accelerate the arc extinguishing process. In other words, the magnetic blow-out effect can be boosted. The enhanced magnetic sheet 112 is in a cuboidal shape according to Fig. 4. However, the embodiments of the present disclosure are not limited to this and the enhanced magnetic sheet 112 may be provided in other shapes, such as cylinder, triangular prism, pentagonal prism, hexagonal prism and other prisms.

In this way, the enhanced magnetic sheet 112 is provided in the stationary contact 10, the magnetic blow-out effect can be boosted and the arc is rapidly transferred to the arc extinguishing chamber.

Referring to Figs. 1A and 1B again, in some embodiments, the arc extinguishing apparatus 100 also includes an arc striking sheet 308. The arc striking sheet 308 may have a bending portion 310. When the movable contact 20 is at a cutoff position where it separates from the stationary contact 10, a distal end of the bending portion 310 gets close to the movable contact 20. The arc path may be increased by enabling the bending portion 310 on the movable arc striking sheet 308 to bend upward. This correspondingly increases a longitudinal length of the arc extinguishing chamber and the arc is lengthened. The longer the arc is, the stronger the resistance gets. The arc voltage also increases since the current of the arc is fixed. It is increasingly hard to maintain the arc voltage as it grows. In such case, the arc may be more easily extinguished.

By providing on the movable arc striking sheet 308 the bending portion 310 that bends upwards, the longitudinal length of the arc extinguishing chamber increases, i.e., the arc is lengthened. The longer the arc is, the stronger the resistance gets. As the voltage grows, it becomes increasingly hard to maintain the burning, which may facilitate the arc extinguishing process.

The movable contact 20 is described below with reference to Figs. 5A and 5B. Fig. 5A illustrates a stereogram of the movable contact in accordance with one embodiment of the present disclosure, and Fig. 5B shows a lateral view of the movable contact in accordance with one embodiment of the present disclosure. As shown, the movable contact 20 as a whole is in a strip shape. In some embodiments, the movable contact 20 may rotate about a rotation axis 203, to connect with and disconnect from the stationary contact 10. Space areas are formed between the first arm 304 and the second arm 306 of each arc chute 302 and between the first clamping portion 402 and the second clamping portion 404. The movable contact 20 is adapted to mate with the stationary contact 10 inside the space areas. In some embodiments, the movable contact 202 includes a plat surface. In some embodiments, the respective arc chutes 302 are arranged in a fan-shape. In such case, the movable contact 120 is such configured that its flat surface is successively in the same plane with the respective arc chutes 302 during the movement. Therefore, the resistance against the transfer of the arc is reduced and the arc can be rapidly transferred.

The arc extinguishing chamber 70 consisting of the arc chutes, the first side plate 50 and the second side plate 60 is further described below with reference to Figs. 6A and 6B. Fig. 6A illustrates a stereogram of the arc extinguishing chamber 70 in accordance with one embodiment of the present disclosure; and Fig. 6B illustrates a front view of the arc extinguishing chamber 70 in accordance with one embodiment of the present disclosure. In some embodiments, as shown in Fig. 6A and 6B, the stacked arc chutes 302 are arranged in a fan shape and the extended surfaces of the respective arc chutes 302 intersect at the rotation axis of the movable contact 20. In this way, during the movement, the flat surface of the movable contact 20 is successively in the same plane with the respective arc chutes 302 arranged in the fan shape, which can advantageously reduce the resistance against the transfer of the arc and rapidly transfer the arc. In some embodiments, projections of the respective arc chutes 302 on the surface 110 of the bending structure 102 (see Fig. 2B) may partially overlap with the stationary arc striking sheet 105. The magnetic field between the stationary arc striking sheet 105 and the arc chutes 302 is thus enhanced. The electromagnetic force is accordingly boosted to facilitate introducing the arc into the arc extinguishing chamber 70. In some embodiments, the respective arc chutes 302 may have a U-shaped structure according to Figs. 6A and 6B. In some embodiments, the respective arc chutes 302 may have a V-shaped structure. In some embodiments, the respective arc chutes 302 may have a W-shaped structure. When the arc chutes 302 are configured with the above structure, the first arm 304 and the second arm 306 of the arc chutes 302 can partially surround or be close to the stationary contact point 104, to boost the strength of the magnetic field near the stationary contact 104 and facilitate the magnetic blow-out.

The structure of the arc chute 302 is further depicted below with reference to Figs. 7A and 7B. Fig. 7A illustrates a stereogram of the first chute in accordance with one embodiment of the present disclosure; and Fig. 7B illustrates a front view of the first chute in accordance with one embodiment of the present disclosure. The first chute is one arc chute among the stacked arc chutes 302. In some embodiments, the first chute 312 as a whole may have a U-shaped structure according to Figs. 7A and 7B. The first chute 312 includes a base 301, a first arm 304 and a second arm 306. The first arm 304 and the second arm 306 extend along two opposite sides of the base 301. In some embodiments, the first chute 312 also may include a riveting portion 318 adapted to be riveted to the first side plate 50 and the second side plate 60. The structure of the first chute 312 is not limited to this and may have different variations.

The structure of the arc chute 302 is further described below with reference to Figs. 8A and 8B. Fig. 8A illustrates a stereogram of the second chute in accordance with one embodiment of the present disclosure; and Fig. 8B illustrates a front view of the second chute in accordance with one embodiment of the present disclosure. The second chute is another arc chute among the stacked arc chutes 302. The second chute 314 as a whole may have a U-shaped structure according to Figs. 8A and 8B. The second chute 314 includes a base 301, a first arm 304 and a second arm 306. The first arm 304 and the second arm 306 extend along two opposite sides of the base 301. In some embodiments, the second chute 314 also may include a riveting portion 318 adapted to be riveted to the first side plate 50 and the second side plate 60. The structure of the second chute 314 is not limited to this and may have different variations.

Compared to the second chute 314, the first arm 304 and the second arm 306 of the first chute 312 have a larger root inner side dimension. In this way, the projection of the first chute 312 on the surface of the stationary contact 10 partially overlaps with stationary arc striking sheet 105, to enhance the magnetic field, increase the magnetic blow-out effect and rapidly transfer the arc to the arc extinguishing chamber 70. Besides, materials are added to the first arm 304 of the first chute 312 compared to the second chute 314. In such case, the electromagnetic force also increases. The electromagnetic force is not strong under small currents. The stationary contact 10 is made to partially overlap with the arc striking sheet by adding materials, to enhance the magnetic field, increase the electromagnetic force and facilitate introducing the arc to the arc extinguishing chamber 70.

The first chute 312 and the second chute 314 may be used separately or in combination. In other words, the stacked arc chutes 302 may only include the first chute 312 and vice versa.

In some embodiments, the first chute 312 having a U-shaped structure is more suitable for currents below a critical value. In some embodiments, the second chute 314 having a U-shaped structure is more suitable for breaking of large currents. The selection and combination may be appropriately made according to the actual working conditions.

The structure of the movable arc striking sheet is further depicted below with reference to Figs. 9A and 9B. Fig. 9A illustrates a stereogram of the movable arc striking sheet in accordance with one embodiment of the present disclosure, and Fig. 9B shows a top view of the movable arc striking sheet in accordance with one embodiment of the present disclosure. The movable arc striking sheet 308 is adapted to mate with the movable contact 20 to introduce the arc into the arc extinguishing chamber 70. In some embodiments, the movable arc striking sheet 308 may include a connecting portion 303 and a bending portion 310 according to Figs. 9A and 9B, wherein the connecting portion 303 is coupled to the first side plate 50 and the second side plate 60. In some embodiments, the bending portion 310 extends in a direction away from the stationary contact 10. In some embodiments, the bending portion 310 extends in a way that forms a given angle with the connecting portion 303. In some embodiments, the angle may be greater than 0 degree and smaller than or equal to 90 degrees. In some embodiments, the angle may be greater than 20 and less than 60 degrees. Accordingly, the bending portion 310 on the movable arc striking sheet 308 is enabled to bend upward, the longitudinal length of the arc extinguishing chamber 70 correspondingly increases. Thus, the arc is lengthened, which may facilitate extinguishing the arc. A groove 316 shown in Fig. 9B is adapted to mate with a first baffle 408 and a second baffle 410 of the gas-producing assembly 40.

The gas-producing assembly 40 is further described below with reference to Figs. 10A and 10B. Fig. 10A illustrates a stereogram of the gas-producing assembly in accordance with one embodiment of the present disclosure; and Fig. 10B illustrates a front view of the gas-producing assembly in accordance with one embodiment of the present disclosure. As shown, the first clamping portion 402 includes a plurality of first teeth 406 arranged in a longitudinal direction and the first baffle 408, wherein the first baffle 408 is disposed adjacent to the plurality of first teeth 406. The second clamping portion 404 consists of a plurality of second teeth 412 arranged in a longitudinal direction and the second baffle 410, wherein the second baffle 410 is disposed adjacent to the plurality of second teeth 412. In some embodiments, the respective first teeth 406 and the first baffle 408 may at least partly isolate the ends of the respective first arms 304, i.e., at least three side faces of the end of the first arm 304 are not exposed to the air. In some embodiments, the respective first teeth 406, the first baffle 408 and the first side plate 50 may completely isolate the ends of the respective first arms 304, i.e., each side face of the end of the first arm 304 makes no contact with the air. In some embodiments, the respective second teeth 412 and the second baffle 410 may at least partly isolate the ends of the respective second arms 306, i.e., at least three side faces of the end of the second arm 306 are not exposed to the air. In some embodiments, the respective second teeth 412, the second baffle 410 and the second side plate 60 may completely isolate the ends of the respective second arms 306. Accordingly, the ends of the first arm 304 and the second arm 306 are isolated by teeth and baffle, or by the mating among the teeth, baffle and side plate, to prevent the arc from reverting and burning again.

In some embodiments, the ends of the first arm 304 and the second arm 306 of the arc chutes 302 are clamped, isolated or wrapped by teeth and baffle, or by the mating among the teeth, baffle and side plate, i.e., the ends are partially or completely insulated and isolated. Embodiments of the present disclosure are not limited to this. In some embodiments, the first clamping portion 402 includes a plurality of first grooves (not shown) arranged in a longitudinal direction, wherein each first groove respectively mates with the end of each first arm 304 and insulatively isolates the end of the first arm 304; the second clamping portion 404 includes a plurality of second grooves (not shown) arranged in a longitudinal direction, wherein the second grooves respectively mate with the end of each second arm 306 and insulatively isolate the end of the second arm 306. In these embodiments, the first clamping portion 402 and the second clamping portion 404 can isolate the ends of the first arm 304 and the second arm 306 without mating with the first side plate 50 and the second side plate 60. In this way, the ends of the first arm 304 and the second arm 306 are isolated by the grooves, to prevent the arc from reverting and burning again.

The clamping portion of the present disclosure is not limited to the above embodiments including a plurality of teeth or a plurality of grooves. Instead, many variations are also feasible. The design may be made according to factors, including the specific space requirements, mating requirements between respective pieces and process aspects etc.

In the embodiments shown by Figs. 10A and 10B, the first clamping portion 402 and the second clamping portion 404 are integrated via their lower portions. Embodiments of the present disclosure are not limited to this. In some embodiments, the first clamping portion 402 and the second clamping portion 404 may be provided in a divided fashion.

The mating between the gas-producing assembly 40 and the arc chute assembly 30 is further described below with reference to Fig. 11, which illustrates a local stereogram of the arc extinguisher in accordance with one embodiment of the present disclosure. As shown, the arc chute assembly 30 includes a plurality of arc chutes 302. In some embodiments, as shown in Fig. 11, the first clamping portion 402 of the gas-producing assembly 40 clamps and isolates the ends of the respective first arms 304, while the second clamping portion 404 clamps and isolates the ends of the respective second arms 306. In some embodiments, there are at least two arc chutes 302. The arc chutes 302 may cut off the arc. An arc cut off by every two arc chutes 302 usually has a voltage of about tens of volts (e.g., 30 to 50 volts) . If the number of arc chutes 302 increases, the total arc voltage will grow correspondingly. In case of high arc voltage, e.g., the arc voltage is well above the power supply voltage, it is impossible to keep the arc burning and the arc will be extinguished. It would be easy to keep the arc burning if the arc voltage is low. In order to boost the arc extinguishing performance of the arc extinguishing chamber 70, the arc needs to rapidly enter the arc chutes of the arc extinguishing chamber, such that the arc chutes 302 may effectively cut the art, thereby achieving the goal of extinguishing the arc rapidly.

In some embodiments, the gas-producing assembly 40 is made of insulating materials. The arc has a high temperature (e.g., up to 900 degrees Celsius) when generated. Due to the high temperature, part of the insulating materials may be decomposed to gas. The gas expands rapidly to push the arc into the arc extinguishing chamber 70. The expanded gas may be released from a direction of the arc chute assembly 30 facing away from the gas-producing assembly 40. In this way, the transfer of the arc may be accelerated by the rapid expansion of the gas generated from the insulating material, so as to extinguish the arc rapidly.

A plurality of teeth is provided in the first clamping portion 402 and the second clamping portion 404, to clamp and isolate the ends of the first arm 304 and the second arm 306 in the arc chute assembly 30. This also facilitates mounting and detachment. The ends of the first arm 304 and the second arm 306 are partially isolated, such that it can prevent the arc from reverting to the vicinity of the ends. For a single arc chute 302, the magnetic field becomes stronger as the arc chute 302 gets close to the stationary contact point 104. In such case, the electromagnetic force experienced by the arc also grows, which facilitates the transfer of the arc to the arc extinguishing chamber 70. However, for a plurality of arc chutes 302, the air medium is broken down more easily as the distance between the arc chutes reduces. The arc, according to its nature, tends to gather at an arc chute 302 intensive area, to maintain stable burning of the arc. If the arc reverts to the vicinity of the end, the electric field is strong as the distance between two arc chutes 302 at the end position is small. In such case, the air medium may be easily exposed to a secondary breakdown, to produce the arc again. In other words, the arc may burn again near the movable contact and the stationary contact. Moreover, the secondary breakdown experienced by the air medium may short out the two adjacent arc chutes. When the air medium is broken down, the two arc chutes experience a short circuit, causing arc voltage drop. The voltage drop of the arc is bad for arc extinguishing. To avoid the arc gathering at the end of the arm of the arc chute 302, the insulating material is arranged in the embodiments of the present disclosure. At least part of the ends of the first arm 304 and the second arm 306 is isolated. In other words, at least part of the surface of the respective ends makes no contact with the air, for example, at least the upper and lower sides as well as the inner side (the side close to the stationary contact) of the ends are not exposed to the air, to protect the air medium from the secondary breakdown and further avoid short circuit between two arc chutes 302. Those skilled in the art should understand that the structures of the first and second clamping portions of the gas-producing assembly are not limited to the above embodiments and may have other variations.

In the above embodiments, the ends of the arms in the arc chutes 302 are clamped and isolated by providing the gas-producing assembly and further arranging teeth or grooves of insulating materials in the gas-producing assembly. As such, the ends are insulated, to prevent the arc from gathering or reverting to the ends of the arms of the arc chutes 302 (which may cause secondary breakdown and produce arc again) . The above embodiments thus may rapidly extinguish the arc.

In some embodiments, the arc chutes 302 are arranged in a fan shape. Embodiments of the present disclosure are not limited to this. The arc chutes 302 also may be arranged in other ways, e.g. in parallel.

Fig. 12 illustrates a local stereogram of the circuit breaker in accordance with one embodiment of the present disclosure. As shown, the circuit breaker 200 includes the arc extinguishing apparatus 100 according to any of the above embodiments. A plurality of chambers is disposed in a housing 202 of the circuit breaker 200 and each chamber may be provided with one arc extinguishing apparatus 100. Fig. 12 only illustrates one arc extinguishing apparatus 100. The structure of the circuit breaker 200 is not restricted to the one shown in Fig. 12 and instead may take other various forms.

Although the arc extinguishing apparatus 100 has been described in particular structures in the above embodiments, the structure of the arc extinguishing apparatus 100 is not limited to those illustrated and may have other variations. For example, the stationary contact, the movable contact, the arc chute and the gas-producing assembly may have different structures.

According to the technical solution of the present disclosure, when the circuit breaker breaks fault currents or critical load currents, the arc may rapidly enter the arc extinguishing chamber and be extinguished. This eases the burn damage to the contact system caused by the arc. When the circuit breaker breaks large-capacity DC loads, the arc transfers rapidly and is lengthened to increase the arc voltage. Accordingly, the DC currents are broken to protect the loads.

According to the solutions of the embodiments of the present disclosure, because of the above improvements and optimizations in the structure of the arc extinguishing apparatus, the arc extinguishing performance is significantly improved by a simple structure. Moreover, the present disclosure is suitable for the arc extinguishing process of both alternating and direct currents.

Various embodiments of the present disclosure have been described above and the described embodiments are optional embodiments of the present disclosure. The above description is only exemplary rather than exhaustive and is not limited to the embodiments of the present disclosure. Although the claims of the present application are drafted for specific combinations of the features, it should be understood that the scope of the present disclosure also includes explicit or implicit features, or any novel features or any novel combinations of the features, no matter whether the features relate to the same solution in any claims or not. Applicant hereby states that new claims may be drafted for these features and/or combinations thereof in the examination procedure of the present application or any further applications derived from the present application.

The selection of terms in the text aims to best explain principles and actual applications of each embodiment and technical improvements made in the market by each embodiment, or enable those ordinary skilled in the art to understand embodiments of the present disclosure. Many modifications and alterations of the present disclosure are obvious for those skilled in the art. Any modifications, equivalent substitutions and improvements shall be included in the protection scope of the present disclosure as long as they are within the spirit and principle disclosed herein.

Claims

An arc extinguishing apparatus (100) , characterized in comprising:

a stationary contact (10) including a stationary contact point (104) ;

a movable contact (20) including a movable contact point (202) adapted to mate with the stationary contact point (104) ;

an arc chute assembly (30) positioned above the stationary contact (10) and including stacked arc chutes (302) , wherein each of the arc chutes (302) includes: a base (301) , a first arm (304) and a second arm (306) , the first arm and the second arm extending from two opposite sides of the base (301) and partially surrounding the stationary contact point (104) ;

a first side plate (50) and a second side plate (60) made of insulating materials and coupled to two sides of the arc chute assembly (30) , to fix the stacked arc chutes (302) ; and

a gas-producing assembly (40) including a first clamping portion (402) and a second clamping portion (404) made of insulating materials, where the first clamping portion (402) clamps and isolates an end of the respective first arm (304) and the second clamping portion (404) clamps and isolates an end of the respective second arm (306) .
The arc extinguishing apparatus (100) of claim 1, characterized in:

the first clamping portion (402) includes: a plurality of first teeth (406) arranged in a longitudinal direction; and a first baffle (408) disposed adjacent to the plurality of first teeth (406) ;

the second clamping portion (404) includes: a plurality of second teeth (412) arranged in a longitudinal direction; and a second baffle (410) disposed adjacent to the plurality of second teeth (412) ;

wherein respective ones of the plurality of first teeth (406) , the first baffle (408) and the first side plate (50) isolate an end of respective the first arm (304) ; and respective ones of the plurality of second teeth (412) , the second baffle (410) and the second side plate (60) isolate an end of the respective second arm (306) .
The arc extinguishing apparatus (100) of claim 1, characterized in:

the first clamping portion (402) includes a plurality of first grooves arranged in longitudinal direction, respectively mating with an end of the respective the first arm (304) and isolating an end of the first arm (304) ;

the second clamping portion (404) includes a plurality of second grooves arranged in longitudinal direction, respectively mating with an end of the respective the second arm (306) and isolating an end of the second arm (306) .
The arc extinguishing apparatus (100) of claim 1, characterized in, further comprising:

a movable arc striking sheet (308) including a connecting portion (303) and a bending portion (310) , wherein the connecting portion (303) is coupled to the first side plate (50) and the second side plate (60) ; the bending portion (310) extends in a direction away from the stationary contact (10) ; a distal end of the bending portion (310) is close to the movable contact (20) when the movable contact (20) is in a cutoff position where it separates from the stationary contact (10) .
The arc extinguishing apparatus (100) of claim 1, characterized in:

the stacked arc chutes (302) are arranged in a fan shape and an extended surface of respective ones of the arc chutes (302) intersects with a rotation axis of the movable contact (20) .
The arc extinguishing apparatus (100) of claim 5, characterized in that:

the movable contact (202) includes a flat surface, and the flat surface is in the same plane with respective ones of the arc chutes (302) successively during movement of the movable contact (20) .
The arc extinguishing apparatus (100) of claim 1, characterized in:

the stationary contact (10) also includes a bending structure (102) disposed at one end, and the stationary contact (10) is positioned on a surface (110) of the bending structure (102) facing the arc chutes (302) .
The arc extinguishing apparatus (100) of claim 7, characterized in further comprising:

an enhanced magnetic sheet (112) disposed at an inner side of the bending structure (102) .
The arc extinguishing apparatus (100) of claim 7, characterized in the stationary contact (10) also includes:

a stationary arc striking sheet (105) comprising a first portion (106) and a second portion (108) , wherein the first portion (106) is positioned on the surface (110) of the bending structure (102) and close to the stationary contact point (104) , and the second portion (108) bends in a direction from the first portion (106) towards the arc chutes (302) and is narrowed.
The arc extinguishing apparatus (100) of claim 9, characterized in:

projections of respective ones of the arc chutes (302) on the surface (110) of the bending structure (102) partially overlap with the stationary arc striking sheet (105) .
The arc extinguishing apparatus (100) of claim 1, characterized in:

space areas are formed between the first arm (304) and the second arm (306) and between the first clamping portion (402) and the second clamping portion (404) ; and the movable contact (20) is adapted to mate with the stationary contact (10) within the space areas.
The arc extinguishing apparatus (100) of claim 1, characterized in:

the stationary contact point (104) is surrounded by the first arms (304) , the second arms (306) and the gas-producing assembly (40) .
The arc extinguishing apparatus (100) of any of claims 1 to 12, characterized in:

respective ones of the arc chutes (302) have U-shaped, V-shaped or W-shaped structure.
A circuit breaker characterized in comprising the arc extinguishing apparatus (100) according to any of claims 1 to 13.