EP3373320B1

EP3373320B1 - Circuit breaker and exhaust structure thereof

Info

Publication number: EP3373320B1
Application number: EP16861408.9A
Authority: EP
Inventors: Shenhu ZHANG; Changqing ZHOU; Weijun GE
Original assignee: Zhejiang Chint Electrics Co Ltd; SEARI Electric Technology Co Ltd
Current assignee: Zhejiang Chint Electrics Co Ltd; SEARI Electric Technology Co Ltd
Priority date: 2015-11-02
Filing date: 2016-09-29
Publication date: 2021-01-27
Anticipated expiration: 2036-09-29
Also published as: WO2017076140A1; BR112018008355A2; BR112018008355B1; EP3373320A4; KR20180105638A; KR102641636B1; EP3373320A1; CN105244242A; RU2702341C1; CN105244242B

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of low voltage electrical apparatus, and more particularly, to an exhaust structure for a circuit breaker as well as to a circuit breaker comprising such an exhaust structure.

2. The Related Art

With the development of technology, the size of circuit breakers is getting smaller and smaller, but the technical performance indexes are getting higher and higher. Circuit breakers will generate high temperature expansion gases during a short-circuit breaking process. As the size of the circuit breaker becomes smaller, if the high-temperature expansion gas is not able to be eliminated in time, an air flow will be formed, which will prevent an arc from effectively entering into an arc extinguishing chamber. Staying of the arc will form an arc backflow, which will cause the arc to stagnate in an arc channel, and result in a long breaking time, severe burning of an arcing plate and the movable/static contacts.
For small circuit breakers, the improvement of exhaust capacity has always been an important means to improve the performance indexes. CN201796768U discloses a wiring switch device with an arc extinguishing device, in particular to an electrical wiring switch device provided with a casing, a terminal connecting chamber and the arc extinguishing device. The wiring switch device comprises an arc extinguishing chamber. An arc extinguishing plate stack with arc extinguishing plates stacked in parallel mutually is arranged in the arc extinguishing chamber, wherein the arc extinguishing plates are kept spaced with each other in a stacking direction. Besides, exhaust flows can exit from the arc extinguishing chamber at the positions of exhaust lateral surfaces. A first flow guide wall element is arranged inside the wiring switch device casing, and at least partial exhaust flow is guided into the terminal connecting chamber by the aid of the first flow guide wall element. CN102243945A discloses an installation switching device, which comprises a housing. The housing comprises an upper wide side, a lower wide side, a front side, a fixed side, a narrow side and an arc extinguishing device. An intermediate piece is arranged inside the housing in a way to make the arc extinguishing device accommodated in a partial space between the upper wide side and the intermediate piece. A first exhaust channel is formed between an exhaust wall extending in a way to be parallel to the wide side and the upper wide side. The first exhaust channel guides exhaust flows from the arc extinguishing device end part directing towards the narrow side to a first exhaust gas hole in a narrow side wall of the housing. An end insulating part is arranged between a narrow side part located on the exhaust gas wall of the intermediate piece and the lower wide side. An intermediate hole is provided on the exhaust gas wall of the intermediate piece. The intermediate hole is aligned with an insulating part hole inside the end insulating part so as to form a second exhaust gas channel. The second exhaust gas channel guides a first branch flow from a part between the end spatial partition and the lower wide side to a second exhaust gas hole in the narrow side wall. CN201796768U and CN102243945A guide the exhaust of air flow through the arrangement of an exhaust channel, so as to improve the problem of air flow stagnation caused by turbulence of the air flow, thereby increasing the exhaust capacity. However, with the continuous miniaturization of circuit breakers, the space within the circuit breaker is getting smaller and smaller, even if the air flow can flow out in order along the exhaust channel, air flow stagnation will still occur due to the large volume of gas and the small space in the circuit breaker, which will affect the result of arc extinguishing.
CN203013659U discloses a circuit breaker provided with an arc running channel. A pedestal and a cover are provided with positioning long protruding diameters, which are symmetrically arranged. The other side of an arc extinguishing chamber, which is far away from the arc running channel, abuts against the positioning long protruding diameters of the pedestal and the cover. Arc dividing protruding diameters are symmetrically disposed on lower sides of the positioning long protruding diameters of the pedestal and the cover. The arc dividing protruding diameters can be used to form a curved arc running channel, and side walls of the pedestal and the cover behind the arc dividing diameters are provided with arc spraying ports. CN203013659U assists extinguishing by cutting off the arc, but CN203013659U still does not solve the problem that the air flow is not able to be exhausted in time.
US 4 620 076 A describes a circuit breaker apparatus, according to the preamble of claim 1, having a molded case forming a plurality of intercommunicating compartments with a circuit breaker structure within a compartment, arc-quenching means in an adjacent compartment, a line terminal in a next adjacent compartment and electrically insulating shield means between the line terminal and the arc-quenching compartment. An arc chute includes a wall of electrically insulating fiber material. The wall is perforated to enable the escape of otherwise explosive gas (air) emitting from the arc chute when contacts of the circuit breaker are open.

SUMMARY

The invention proposes an exhaust structure for a circuit breaker, which solves the exhaust problem of a miniature circuit breaker by expanding the exhaust space and increasing the exhaust volume.
According to the present invention, an exhaust structure for a circuit breaker is provided as defined in claim 1. The exhaust structure comprises an exhaust port aligned with a tail of an arc extinguish chamber. An exhaust space of the exhaust port is configured to overlap with a wiring device of the circuit breaker. When the wiring device is not connected, The exhaust space is arranged to house the wiring device when the wiring device is not connected. The exhaust space is arranged to be vacated when the wiring device is connected.
Three exhaust ports are provided. The three exhaust ports are formed on a housing of the circuit breaker, and are respectively aligned with the top, middle and bottom of the tail of the arc extinguishing chamber. The three exhaust ports are arranged on the housing at equal intervals. An exhaust space of the exhaust port aligned with the middle of the tail of the arc extinguishing chamber is arranged to overlap with the wiring device of the circuit breaker.
According to an embodiment, a base and a cover of the housing of the circuit breaker are provided with corresponding grooves, respectively. When the base and the cover are mounted, the grooves form the three exhaust ports, and at least one exhaust port is configured to be split by components of the circuit breaker.
According to an embodiment, the exhaust structure further comprises at least one block protrusion. The block protrusion extends from the tail of the arc extinguish chamber to a position of at least one exhaust port in lateral direction, and extends from one exhaust port to another adjacent exhaust port in longitudinal direction.
According to an embodiment, the block protrusion is formed on the housing of the circuit breaker. One end of the block protrusion is in contact with the tail of the arc extinguishing chamber and supports the arc extinguishing chamber.
According to a further aspect of the present invention, a circuit breaker is provided. At least one exhaust port is formed on a housing of the circuit breaker, the exhaust port is aligned with a tail of an arc extinguish chamber. An exhaust space of the exhaust port is overlapped with a wiring device of the circuit breaker. When the wiring device is not connected, the wiring device occupies the exhaust space. When the wiring device is connected, the exhaust space is vacated.
Three exhaust ports are formed on the housing of the circuit breaker. The three exhaust ports are respectively aligned with the top, middle and bottom of the tail of the arc extinguishing chamber. The three exhaust ports are arranged with equal intervals. An exhaust space of the exhaust port aligned with the middle of the tail of the arc extinguishing chamber overlaps with the wiring device of the circuit breaker.
According to an embodiment, the housing of the circuit breaker comprises a base and a cover. The base and the cover are provided with corresponding grooves respectively. When the base and the cover are mounted, the grooves form the three exhaust ports, and at least one exhaust port is split by components of the circuit breaker.
According to an embodiment, at least one block protrusion is formed on the housing of the circuit breaker. The block protrusion extends from the tail of the arc extinguish chamber to a position of at least one exhaust port in lateral direction, and extends from one exhaust port to another adjacent exhaust port in longitudinal direction.
According to an embodiment, one end of the block protrusion is in contact with the tail of the arc extinguishing chamber and supports the arc extinguishing chamber.
The exhaust structure of circuit breaker of the present invention utilizes an unoccupied space of the wiring device, increases the quantity of exhaust ports, expands the exhaust space, thereby significantly improving the exhaust capability. The exhaust structure is also provided with a block protrusion for cutting off an arc. The block protrusion also serves as a support for the arc extinguish chamber, avoiding reduction of the arc extinguish capability due to a shifting of the arc extinguish chamber caused by an impact.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features, natures, and advantages of the invention will be apparent by the following description of the embodiments incorporating the drawings, wherein

FIG. 1 illustrates a plan view of an exhaust structure for a circuit breaker, the exhaust structure being according to an embodiment of the present invention.
FIG. 2 illustrates a perspective view of an exhaust structure for a circuit breaker, the exhaust structure being according to an embodiment of the present invention.
FIG. 3a and FIG. 3b illustrate the structure of a base and a cover of a circuit breaker comprising the exhaust structure according to an embodiment of the present invention.
FIG. 4 illustrates a working state of a wiring device of a circuit breaker comprising the exhaust structure according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention discloses an exhaust structure of circuit breaker. The exhaust structure comprises an exhaust port, the exhaust port is aligned with a tail of an arc extinguish chamber. An exhaust space of the exhaust port is overlapped with a wiring device of the circuit breaker. When the wiring device is not connected, the wiring device occupies the exhaust space. When the wiring device is connected, the exhaust space is vacated.
According to the invention, the exhaust structure comprises at least three exhaust ports. The at least three exhaust ports are aligned with the tail of the arc extinguish chamber, the at least three exhaust ports are arranged with equal intervals. The exhaust structure comprises three exhaust ports, the three exhaust ports are respectively aligned with the top, middle and bottom of the tail of the arc extinguishing chamber. An exhaust space of the exhaust port aligned with the middle of the tail of the arc extinguishing chamber overlaps with the wiring device of the circuit breaker. According to an embodiment, the exhaust structure further comprises at least one block protrusion. The block protrusion extends from the tail of the arc extinguish chamber to a position of at least one exhaust port in lateral direction, and extends from one exhaust port to another adjacent exhaust port in longitudinal direction.
As shown in FIG. 1 and FIG. 2, FIG. 1 and FIG. 2 illustrate a plan view and a perspective view of an exhaust structure of a circuit breaker according to an embodiment of the present invention respectively. According to the illustrated embodiment, the exhaust structure comprises three exhaust ports: a first exhaust port 101, a second exhaust port 102 and a third exhaust port 103, and a block protrusion 104. The three exhaust ports and the block protrusion are all formed on a housing of the circuit breaker. As shown in FIG. 3a and FIG. 3b, the housing of the circuit breaker is formed by combining a base 105 and a cover 108. According to FIG. 3a, the base 105 is provided with a first base groove 501, a second base groove 502, a third base groove 503 and a base protrusion 504. The base 105 is further provided with a base contact plate 507. According to FIG. 3b, the cover 108 is provided with a first cover groove 801, a second cover groove 802, a third cover groove 803 and a cover protrusion 804. The cover 108 is further provided with a cover contact plate 807. The first base groove 501, the second base groove 502, the third base groove 503, the base protrusion 504 and the base contact plate 507 are arranged in "one-to-one" correspondence with the first cover groove 801, the second cover groove 802, the third cover groove 803, the cover protrusion 804 and the cover contact plate 807. When the base 105 and the cover 108 are mounted, the grooves and the protrusions on the base and the cover are aligned with each other to form the first exhaust port 101, the second exhaust port 102, the third exhaust port 103 and the block protrusion 104. Wherein, the second exhaust port 102 is directly formed by splicing the second base groove 502 and the second cover groove 802. The third exhaust port 103 is directly formed by splicing the third base groove 503 and the third cover groove 803. The block protrusion 104 is directly formed by splicing the base protrusion 502 and the over protrusion 804. The second exhaust port 102, the third exhaust port 103 and the block protrusion 104 are all realized by single structure. The first exhaust port 101 is separated into two portions. The base contact plate 507 and the cover contact plate 807 form a complete contact plate when spliced. An end surface 571 of the base contact plate 507 and the first base groove 501 form a first portion 101a of the first exhaust port. And an end surface 871 of the cover contact plate 807 and the first cover groove 801 form a second portion 101b of the first exhaust port. The first portion 101a and the second portion 101b form the first exhaust port 101, as shown in FIG. 2. According to the illustrated embodiment, at least one exhaust port (the first exhaust port) of the three exhaust ports is split by components (the contact plate) of the circuit breaker.
Back to FIG. 1, the first exhaust port 101 is aligned with the top of the tail of the arc extinguishing chamber 106, the second exhaust port 102 is aligned with the middle of the tail of the arc extinguishing chamber 106, and the third exhaust port 103 is aligned with the bottom of the tail of the arc extinguishing chamber 106. According to the embodiment shown in FIG. 1, the block protrusion 104 has a zigzag shape which is similar to the letter "Z". A top end 141 of the block protrusion 104 is in contact with the tail of the arc extinguishing chamber 106. The block protrusion 104 is in contact with the tail of the arc extinguishing chamber 106 so as to support the arc extinguishing chamber 106. When an arc enters into the arc extinguishing chamber 106 during a breaking process, a powerful thrust will be instantaneously generated and act on the arc extinguishing chamber 106. In order to prevent the arc extinguishing chamber 106 from being skewed by the thrust, the block protrusion 104 may play a role of supporting and positioning, so as to avoid reduction of the arc extinguish capability due to a shifting of the arc extinguish chamber caused by an impact. Continue with FIG. 1, viewed from a longitudinal direction, the position where the top end 141 of the block protrusion 104 is in contact with the arc extinguishing chamber 106 is approximately in the middle of the arc extinguishing chamber 106, or the same height as the second exhaust port 102. The position of a bottom end of the block protrusion 104 is approximately at the bottom of the arc extinguishing chamber 106, or the same height as the third exhaust port 103. Viewed from a lateral direction, the block protrusion 104 extends from the arc extinguishing chamber 106 to a position beneath the second exhaust port 102, substantially covering a distance from the closest exhaust port (second exhaust port 102) to the arc extinguishing chamber 106. With the above-described arrangement, the block protrusion 104 may effectively cut off the arc and air flow. Although the illustrated block protrusion 104 has a zigzag shape which is similar to the letter "Z", it should be noted that the block protrusion 104 may be in other shapes. However, the shape of the block protrusion 104 shall satisfy the following conditions: the block protrusion 104 extends from the tail of the arc extinguish chamber to a position of at least one exhaust port in lateral direction, and the block protrusion extends from one exhaust port to another adjacent exhaust port in longitudinal direction.
The distance between the first exhaust port 101, the second exhaust port 102, and the third exhaust port 103 is substantially equal, which is approximately half of the height of the arc extinguishing chamber 106. The sizes of the openings of the first exhaust port 101, the second exhaust port 102, and the third exhaust port 103 are all between 1.8mm-3mm, and the first exhaust port 101, the second exhaust port 102, and the third row. The size of the opening of the air port 103 is generally not set to be the same, but it may be set to be the same. Generally, only one opening range needs to be limited. The first exhaust port 101, the second exhaust port 102, and the third exhaust port 103 formed on the base 105 and the cover 108 increase the number of exhaust passages and also increase the volume of the exhaust space.
It should be particularly noted that the position where the second exhaust port 102 is located is overlapped with a wiring device of the circuit breaker. FIG. 4 illustrates a working state of a wiring device of a circuit breaker with the exhaust structure. As shown in FIG. 4, two wiring devices of the circuit breaker are disclosed, including a first wiring device 401 on the left side and a second wiring device 402 on the right side. It should be noted that, the wiring device of the circuit breaker shown in FIG. 4 is for the purpose of illustrating the position of the second exhaust port 102, it is not intended to impose any limit on the wiring device itself. An exhaust space 122 corresponding to the second exhaust port 102 is overlapped with the wiring device. When the wiring device is not connected, such as the first wiring device 401 on the left side in FIG. 4, the wiring device will occupy the exhaust space 122. When the wiring device is connected, such as the second wiring device 402 on the right side in FIG. 4, the wiring device is lifted upwards to vacate the exhaust space 122. When the circuit breaker is in use, the wiring device will inevitably be lifted upwards for connecting, leaving the exhaust space 122 free. Therefore, when the circuit breaker is in use, the second exhaust port 102 and the exhaust space 122 can be put into use, thereby increasing the exhaust space.
It should be noted that although the embodiments described above have three exhaust ports and a block protrusion, those skilled in the art may configure the number and positions of the exhaust ports according to actual requirements, and configure or cancel the block protrusion as needed. The exhaust structure proposed by the present invention mainly comprises an exhaust port, the exhaust port is aligned with a tail of an arc extinguish chamber. An exhaust space of the exhaust port is overlapped with a wiring device of the circuit breaker. When the wiring device is not connected, the wiring device occupies the exhaust space. When the wiring device is connected, the exhaust space is vacated.
The present invention also provides a circuit breaker with the exhaust structure mentioned above. At least one exhaust port is formed on a housing of the circuit breaker, the exhaust port is aligned with a tail of an arc extinguish chamber. An exhaust space of the exhaust port is overlapped with a wiring device of the circuit breaker. When the wiring device is not connected, the wiring device occupies the exhaust space. When the wiring device is connected, the exhaust space is vacated.
According to an embodiment, at least three exhaust ports are formed on the housing of the circuit breaker. The at least three exhaust ports are aligned with the tail of the arc extinguish chamber, and the at least three exhaust ports are arranged with equal intervals. At least one block protrusion is formed on the housing of the circuit breaker. The block protrusion extends from the tail of the arc extinguish chamber to a position of at least one exhaust port in lateral direction, and extends from one exhaust port to another adjacent exhaust port in longitudinal direction. It should be noted that those skilled in the art may configure the number and positions of the exhaust ports, provide or cancel the block protrusion according to actual requirements.
According to an embodiment, for example, in a circuit breaker with the exhaust structure as illustrated above, three exhaust ports are formed on the housing of the circuit breaker. The three exhaust ports are respectively aligned with the top, middle and bottom of the tail of the arc extinguishing chamber. An exhaust space of the exhaust port aligned with the middle of the tail of the arc extinguishing chamber overlaps with the wiring device of the circuit breaker. The housing of the circuit breaker comprises a base and a cover. The base and the cover are provided with corresponding grooves respectively. When the base and the cover are mounted, the grooves form the three exhaust ports. At least one exhaust port is split by components of the circuit breaker. For example, in a circuit breaker with the exhaust structure as illustrated above, the first exhaust port is separated into two portions by the contact plate. One end of the block protrusion is in contact with the tail of the arc extinguishing chamber and supports the arc extinguishing chamber.
The exhaust structure of circuit breaker of the present invention utilizes an unoccupied space of the wiring device, increases the quantity of exhaust ports, expands the exhaust space, thereby significantly improving the exhaust capability. The exhaust structure is also provided with a block protrusion for cutting off an arc. The block protrusion also serves as a support for the arc extinguish chamber, avoiding reduction of the arc extinguish capability due to a shifting of the arc extinguish chamber caused by an impact.
The above embodiments are provided to those skilled in the art to realize or use the invention, under the condition that various modifications or changes can be made by those skilled in the art without departing from the scope of the Claims.

Claims

An exhaust structure for a circuit breaker comprising a wiring device, the exhaust structure comprising a housing including an exhaust structure, characterized in that the exhaust structure comprises three exhaust ports (101, 102, 103) arranged at equal intervals on the housing, a first exhaust port (101), a second exhaust port (102) and a third exhaust port (103) respectively aligned with the top, middle and bottom of a tail of an arc extinguish chamber (106), wherein:
the exhaust port (102) aligned with the middle of the tail of the arc extinguishing chamber (106) includes an exhaust space arranged to overlap with the wiring device of the circuit breaker, and

the exhaust space is arranged to house the wiring device when the wiring device is not connected, and the exhaust space is arranged to be vacated when the wiring device is connected.
The exhaust structure for a circuit breaker according to claim 1, wherein the housing comprises a base (105) and a cover (108) provided with corresponding grooves (501, 502, 503, 801, 802, 803) respectively, when the base (105) and the cover (108) are mounted, the grooves (501, 502, 503, 801, 802, 803) form the three exhaust ports (101, 102, 103), and at least one exhaust port (102, 103) is configured to be split by components of the circuit breaker.
The exhaust structure for a circuit breaker according to claim 1, further comprising at least one block protrusion (104) extending from the tail of the arc extinguish chamber (106) to a position of at least one exhaust port (102) of the three exhaust ports (101, 102, 103) in lateral direction, and extending from one exhaust port to another adjacent exhaust port (103) of the three exhaust ports (101, 102, 103) in longitudinal direction.
The exhaust structure for a circuit breaker according to claim 3, wherein the block protrusion is formed on the housing of the circuit breaker, and one end of the block protrusion (104) is in contact with the tail of the arc extinguishing chamber (106) and supports the arc extinguishing chamber.
A circuit breaker comprising a wiring device and a exhaust structure according to any of claims 1-4.