Explosion-proof circuit breaker

Abstract

The invention discloses an explosion-proof circuit breaker, and the circuit breaker is characterized in that an arc extinguishing structure is used for extinguishing an electric arc generated when a first contact is separated from a second contact; the arc extinguishing structure comprises an arc extinguishing shell and N arc extinguishing grid plates, wherein N is greater than or equal to 3; all the arc extinguishing grid plates are fixed on the arc extinguishing shell and are sequentially stacked along one direction, an airflow gap exists between every two adjacent arc extinguishing grid plates, and the number of the airflow gaps is N-1; one end, close to the first contact and the second contact, of the airflow gap is an inlet end, and one end, away from the first contact and the second contact, of the airflow gap is an outlet end; the bottom plate and the arc extinguishing shell jointly form a first airflow channel and a second airflow channel, and the first airflow channel and the second airflow channel are separated from each other; the airflow gaps are divided into two groups, namely a first airflow gap and a second airflow gap, the discharge end of the first airflow gap is communicated with the first airflow channel, and the discharge end of the second airflow gap is communicated with the second airflow channel; the arc extinguishing structure has the advantage of being good in arc extinguishing effect.

Description

Technical Field

[0001] The present application relates to the electrical field of low-voltage switches, and in particular to an explosion-proof circuit breaker. Background Art

[0002] Existing explosion-proof circuit breakers often directly place existing small circuit breakers in explosion-proof covers. Although such a structure can achieve explosion-proof effects, the performance of the circuit breaker is constrained by the structure of the small circuit breaker itself and is difficult to improve.

[0003] The existing small circuit breakers have an opening on the casing, and the rear of the arc extinguishing chamber is connected to the opening through an air duct, so that the arc gas after arc extinguishing can be discharged from the opening of the casing to achieve the arc extinguishing effect. However, for explosion-proof circuit breakers, its casing is basically closed, and the arc gas is not allowed to be discharged to the outside. The arc gas must be eliminated inside the circuit breaker. Obviously, the arc extinguishing chamber and air duct structure of conventional small circuit breakers cannot achieve this.

[0004] Therefore, how to design a new exhaust structure that can eliminate the arc inside the circuit breaker is crucial for explosion-proof circuit breakers. Summary of the invention

[0005] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and to provide an explosion-proof circuit breaker.

[0006] The present application provides: an explosion-proof circuit breaker, wherein a cover shell has an inner cavity, and the bottom of the cover shell has an inner cavity opening; a bottom plate is fixed to the cover shell and used to close the inner cavity opening; the inner cavity includes at least one pole space, each pole space has a group of contact systems and arc extinguishing structures; the contact system includes a first contact and a second contact, the first contact and the second contact have a contact state and a separation state; the arc extinguishing structure is used to extinguish the arc generated when the first contact and the second contact are separated; the arc extinguishing structure includes an arc extinguishing shell and N arc extinguishing grids, N ≥ 3; all arc extinguishing grids are fixed to the arc extinguishing shell The arc extinguishing grids are stacked in sequence along one direction, there is an airflow gap between two adjacent arc extinguishing grids, and the number of the airflow gaps is N-1; the end of the airflow gap close to the first contact and the second contact is the entrance end, and the end away from the first contact and the second contact is the discharge end; the bottom plate and the arc extinguishing shell together form a first airflow channel and a second airflow channel, and the first airflow channel and the second airflow channel are separated from each other; the airflow gap is divided into two groups, namely the first airflow gap and the second airflow gap, the discharge end of the first airflow gap is connected to the first airflow channel, and the discharge end of the second airflow gap is connected to the second airflow channel.

[0007] In some embodiments of the present application, it also includes a dividing rib, a first blocking portion and a second blocking portion; the dividing rib is fixed on the base plate or is an integral part with the base plate, and is used to separate the first airflow channel from the second airflow channel; the first blocking portion is fixed on the arc extinguishing shell or is an integral part with the arc extinguishing shell or is fixed on the base plate or is an integral part with the base plate, and the first blocking portion is in the first airflow gap, blocking the discharge end of the first airflow gap from the second airflow channel; the second blocking portion is fixed on the arc extinguishing shell or is an integral part with the arc extinguishing shell or is fixed on the base plate or is an integral part with the base plate, and the second blocking portion is in the second airflow gap, blocking the discharge end of the second airflow gap from the first airflow channel.

[0008] In some embodiments of the present application, the first blocking portion has a first inclined surface or a first curved surface in the first airflow gap, and the first inclined surface or the first curved surface forms a first Laval nozzle aligned with the first airflow channel inside the first airflow gap; the second blocking portion has a second inclined surface or a second curved surface in the second gap, and the second inclined surface or the second curved surface forms a second Laval nozzle aligned with the second airflow channel inside the second airflow gap.

[0009] In some embodiments of the present application, the arc extinguishing shell includes a bracket, on which N grid mounting grooves are arranged in sequence, a partition rib is provided between two adjacent grid mounting grooves, and the first blocking portion and the second blocking portion are both part of the partition rib; the notch of the grid mounting groove faces the base plate, at least one side of the grid mounting groove has a card slot, the card slot is connected to the grid mounting groove, the arc extinguishing grid has a fixing protrusion adapted to the card slot, and during installation, the arc extinguishing grid is pushed into the grid mounting groove from the notch so that the fixing protrusion is carded into the card slot.

[0010] In some embodiments of the present application, the arc extinguishing shell includes an upper cover and a bracket, the arc extinguishing grid is arranged on the bracket, and the upper cover is arranged on the bracket; the upper cover has a main body, a disconnecting channel is opened on the main body, and the disconnecting channel is located above the entrance end; the first contact includes a first contact point, and the second contact includes a second contact point, and the contact and separation of the first contact and the second contact are both realized by the first contact point and the second contact point; the first contact point is always in the disconnecting channel, and at least a part of the second contact is in the disconnecting channel when it is in the final position of the separation state.

[0011] In some embodiments of the present application, a magnetizing component is embedded in the main body, and the magnetizing component includes a first magnetic part, a second magnetic part and a third magnetic part; the first magnetic part and the second magnetic part are respectively arranged on both sides of the separation path of the first contact and the second contact, and the third magnetic part is arranged close to the first contact; the first magnetic part and the third magnetic part, and the second magnetic part and the third magnetic part are all in abutment relationship, or the magnetizing component is an integral part.

[0012] In some embodiments of the present application, the upper cover and the magnetizing component are snap-connected.

[0013] In some embodiments of the present application, a magnetizer installation groove is provided on the upper cover, the groove opening of the magnetizer installation groove faces the bracket, the magnetizer installation groove is located at the periphery of the separating channel, the bracket has an abutment portion extending into the magnetizer installation groove, the magnetizer is in the magnetizer installation groove and abuts against the abutment portion.

[0014] In some embodiments of the present application, the first contact is fixed to the inner cavity wall by a fastener or a nut in the inner cavity wall, and the first contact has a notch; the upper cover also includes a mating portion, which is located on one side of the main body and below the first contact; the mating portion has an avoidance groove and a boss, one end of the fastener is in the avoidance groove, and the boss extends into the notch and fits with the notch.

[0015] In some embodiments of the present application, the first contact includes a contact assembly portion and a connecting portion, the contact assembly portion and the connecting portion are spaced apart, and the contact assembly portion is used to install the first contact; the upper cover has a baffle, and the baffle is inserted into the space between the contact assembly portion and the connecting portion.

[0016] In some embodiments of the present application, the bottom plate has a sunken area, the arc-extinguishing housing is partially embedded in the sunken area, and the sunken area is a component of the first airflow channel and the second airflow channel.

[0017] In some embodiments of the present application, the arc-extinguishing housing has an exhaust port on one side of the last arc-extinguishing grid, and the first airflow channel and the second airflow channel are both connected to the exhaust port.

[0018] In some embodiments of the present application, the number of the first airflow gaps is at least two, and there is a second airflow gap between every two adjacent first airflow gaps.

[0019] In some embodiments of the present application, the number of the second airflow gaps is at least two, and there is a first airflow gap between every two adjacent second airflow gaps.

[0020] In some embodiments of the present application, all arc-extinguishing grids are arranged along a straight line direction or a curved line direction.

[0021] In some embodiments of the present application, a first guide portion is provided on the wall of the inner cavity, the first guide portion extends to the inner cavity opening, and a second guide portion is provided on the arc extinguishing shell, the second guide portion and the first guide portion form a guide structure for installing the arc extinguishing shell.

[0022] In some embodiments of the present application, the bottom plate and the cover shell form a staggered structure, and the staggered structure surrounds the inner cavity opening.

[0023] In some embodiments of the present application, a glue-filling structure is provided between the bottom plate and the cover shell, and the glue-filling structure surrounds the inner cavity opening.

[0024] In some embodiments of the present application, in the height direction, the position of the contact system is higher than the position of the arc extinguishing grid.

[0025] The beneficial effects of this application include: With this structure, the arc extinguishing structure of each pole utilizes the bottom plate of the circuit breaker casing and the arc extinguishing shell to form two separated air flow channels (the first air flow channel and the second air flow channel), and divides the arc gas from the same arc extinguishing structure into two parts. Since the two air flow channels are separated from each other, it is beneficial to disperse the arc gas to extinguish the arc and prevent the arc from gathering together and being difficult to eliminate. Such a structure is very suitable for explosion-proof circuit breakers. There is no need to add air outlet holes on the circuit breaker casing, and the arc can be eliminated inside. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work. Figure 1 An exploded view of the bottom direction of the explosion-proof circuit breaker of Example 1 of the present application is shown; Figure 2 A cross-sectional view of an explosion-proof circuit breaker according to Embodiment 1 of the present application is shown; Figure 3 A schematic diagram of a cover of Embodiment 1 of the present application is shown; Figure 4 A schematic diagram of the bottom plate of Example 1 of the present application is shown; Figure 5 A schematic diagram showing the cooperation between the bottom plate and the arc extinguishing structure in Example 1 of the present application is shown; Figure 6 A 3D cross-sectional view of the bottom plate and the arc extinguishing structure in accordance with Embodiment 1 of the present application is shown; Figure 7 A schematic diagram showing the cooperation between the arc-extinguishing grid and the bracket in Example 1 of the present application (the last arc-extinguishing grid explodes); Figure 8 A schematic diagram of the arc extinguishing structure of Embodiment 1 of the present application is shown; Fig. 9 A cross-sectional view of a first airflow gap and a second airflow gap in Embodiment 1 of the present application is shown; Fig.10 A schematic diagram showing the coordination between the arc extinguishing structure and the contact system in Embodiment 1 of the present application is shown; Fig.11 A cross-sectional view of the installation location of the magnetizing component of the arc extinguishing structure of Example 1 of the present application is shown; Fig.12 Shows Fig.10 Schematic diagram of the first contact and the second contact after removing the nut; Fig.13 A positional relationship diagram of the magnetizing component, the first contact, and the second contact in Example 1 of the present application is shown. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0028] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0029] In addition, the terms "primary" and "secondary" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "primary" or "secondary" may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In the present application, unless otherwise clearly specified and limited, when a main feature is “above” or “below” a second feature, it can mean that the main feature and the second feature are in direct contact, or the main feature and the second feature are in indirect contact through an intermediate medium. Moreover, when a main feature is “above”, “above” or “above” a second feature, it can mean that the main feature is directly above or obliquely above the second feature, or simply means that the main feature is higher in level than the second feature. When a main feature is “below”, “below” or “below” a second feature, it can mean that the main feature is directly below or obliquely below the second feature, or simply means that the main feature is lower in level than the second feature. Example

[0032] like Figure 1-Figure 13 As shown, embodiment 1 of the present application provides an explosion-proof circuit breaker, including the following structure: The housing 100 has an inner cavity 101, and an inner cavity opening 101a is provided at the bottom of the housing 100. The components inside the circuit breaker can be placed into the inner cavity 101 through the inner cavity opening 101a.

[0033] Since this embodiment is a 4-pole circuit breaker, its inner cavity 101 includes 4-pole spaces. A set of contact systems and arc extinguishing structures are arranged in each pole space. Of course, in addition to this, the number of pole spaces can be 1 pole (corresponding to a 1-pole circuit breaker), 2 poles (corresponding to a 2-pole circuit breaker), and 3 poles (corresponding to a 3-pole circuit breaker).

[0034] The bottom plate 200 is fixed to the cover shell 100 to close the inner cavity opening 101a. The bottom plate 200 and the cover shell 100 are fastened with screws, but they can also be fixed by riveting. After the bottom plate 200 and the cover shell 100 are assembled, an interlaced structure is formed between the bottom plate 200 and the cover shell 100, and the interlaced structure surrounds the inner cavity opening 101a. The interlaced structure here is specifically that a first protruding structure 201 is provided on the bottom plate 200, and the first protruding structure 201 is annular, and a second protruding structure 102 is provided on the cover shell 100, and the second protruding structure 102 is annular, and the first protruding structure 201 and the second protruding structure 102 are interlaced with each other. Of course, in addition to this, the interlaced structure can also be changed to a pair of grooves and protrusions.

[0035] Here, since the second protruding structure 102 surrounds the inner cavity opening 101a, a groove structure is formed on the side of the second protruding structure 102 away from the inner cavity opening 101a, and glue can be poured into the groove structure to form a glue pouring structure, and this glue pouring is formed between the bottom plate 200 and the shell 100 (surrounding the inner cavity opening 101a), further improving the sealing performance. Of course, the groove structure required for the glue pouring structure here can also be formed without the second protruding structure 102, for example, a groove structure for glue pouring is separately opened on the shell 100.

[0036] The contact system includes a first contact 301 and a second contact 302. The first contact 301 and the second contact 302 have a contact state and a separation state. The second contact 302 is a moving contact, and the contact and separation with the first contact 301 are achieved through the movement of the second contact 302. The first contact 301 is a stationary contact, but it is not excluded that it is a moving contact (second moving contact).

[0037] The arc extinguishing structure includes an arc extinguishing housing 400 and N arc extinguishing grids 410, where N is 11. Of course, the number of arc extinguishing grids 410 here can be any number other than 11, as long as N ≥ 3. All arc extinguishing grids 410 are arranged in one direction, where the arrangement direction is a straight line direction, that is, a direction parallel to the length of the pole space; of course, the arrangement in one direction here does not specifically refer to a straight line direction, it can also be a curved line direction, that is, the arc extinguishing grids 410 can also be arranged along a curve (for example, a curve that fits the trajectory of the second contact 302).

[0038] There is an airflow gap 420 between two adjacent arc-extinguishing grids 410. The number of airflow gaps 420 here is N-1, that is, at least 2, and in this embodiment, it is 10. All the airflow gaps 420 here have an entry end 4201 close to the first contact 301 and the second contact 302 (arc gas enters the airflow gap 420), and also have an exit end 4202 away from one end of the first contact 301 and the second contact 302 (arc gas exits the airflow gap 420). Here, the bottom plate 200 and the arc-extinguishing housing 400 jointly form a first airflow channel 430a and a second airflow channel 430b, and the first airflow channel 430a and the second airflow channel 430b are separated from each other.

[0039] The airflow gap 420 is divided into two groups, namely the first airflow gap 420a and the second airflow gap 420b. The discharge end 4202 of the first airflow gap 420a is aligned with the first airflow channel 430a, and the two are connected; the discharge end 4202 of the second airflow gap 420b is aligned with the second airflow channel 430b, and the two are connected. Here, the first airflow gap 420a is not connected to the second airflow channel 430b, and the second airflow gap 420b is not connected to the first airflow channel 430a. Here, the number of the first airflow gap 420a and the second airflow gap 420b does not have to be the same, and can also be different. The closer the number is to the same, the more evenly the arc gas can be distributed, the highest utilization rate of the arc extinguishing chamber, and the better the arc extinguishing performance.

[0040] In this way, the arc extinguishing structure of each pole utilizes the bottom plate 200 of the circuit breaker casing and the arc extinguishing shell 400 to form two separated air flow channels (the first air flow channel 430a and the second air flow channel 430b), and divides the arc gas from the same arc extinguishing structure into two parts. Since the two air flow channels are separated from each other, this is conducive to dispersing the arc gas to extinguish the arc and prevent the arc from gathering together and being difficult to eliminate. Such a structure is very suitable for explosion-proof circuit breakers. There is no need to add air outlet holes on the circuit breaker casing, and the arc can be eliminated inside.

[0041] For the first airflow gap 420a and the second airflow gap 420b, the most preferred method is that the first airflow gap 420a and the second airflow gap 420b are spaced apart, that is, there is a second airflow gap 420b between each two adjacent first airflow gaps 420a, or it can be said that there is a first airflow gap 420a between each two adjacent second airflow gaps 420b. In this way, there is also a certain distance between the discharge ends 4202 of the two first airflow gaps 420a (second airflow gaps 420b), which will make the arc gas from multiple first airflow gaps 420a (second airflow gaps 420b) in the first airflow channel 430a (second airflow channel 430b) converge as late as possible, which will be conducive to the extinction of the arc. Of course, this interlaced method is only the most preferred method. As other methods, the first airflow gaps 420a can be concentrated together, or they can be interspersed with several second airflow gaps 420b. There are many such distribution methods, and examples are not given here one by one.

[0042] Generally speaking, in the height direction, the contact system is located above all the arc extinguishing grids 410. Similarly, in the height direction, all the airflow gaps 420 are located above the airflow channels.

[0043] The communication relationship between the airflow channel and the airflow gap 420 is specifically achieved as follows: The bottom plate 200 is integrally formed with a separation rib 210, which is a component of the airflow channel (only one part, the other components of the airflow channel include the side of the bottom plate 200 facing the arc-extinguishing bracket 402 and the arc-extinguishing bracket 402), that is, the first airflow channel 430a and the second airflow channel 430b can be separated by the separation rib 210. Of course, in addition to this, the separation rib 210 can also be formed separately from the bottom plate 200 and then fastened together.

[0044] The first blocking portion 440a (the number is the same as the number of the first airflow gap 420a) is located in the first airflow gap 420a. The first blocking portion 440a is set so that the discharge end 4202 of the first airflow gap 420a is reduced to align with the first airflow channel 430a, which achieves the effect of blocking the discharge end 4202 of the first airflow gap 420a from the second airflow channel 430b (the airflow only flows to the first airflow channel 430a). In this embodiment, the first blocking portion 440a is an integral part with the arc extinguishing housing 400 (which will be described in detail below). Of course, in addition to this, the first blocking portion 440a can also be independently formed and fixed on the arc extinguishing housing 400, or it can be fixed on the bottom plate 200; of course, it can also be an integral part with the bottom plate 200.

[0045] The second blocking portion 440b (the number is the same as the second airflow gap 420b) is located in the second airflow gap 420b. The second blocking portion 440b is set so that the discharge end 4202 of the second airflow gap 420b is reduced to align with the second airflow channel 430b, which achieves the effect of blocking the discharge end 4202 of the second airflow gap 420b from the first airflow channel 430a (the airflow only flows to the second airflow channel 430b). In this embodiment, the first blocking portion 440a is an integral part with the arc extinguishing housing 400 (detailed description will be given below). Of course, in addition to this, the second blocking portion 440b can also be independently formed and fixed on the arc extinguishing housing 400, or it can be fixed on the bottom plate 200; of course, it can also be an integral part with the bottom plate 200.

[0046] Through the above-mentioned first blocking part 440a, the second blocking part 440b and the dividing rib 210, the structure is very simple, which can effectively realize the connection between the first airflow gap 420a and the first airflow channel 430a, and the connection between the second airflow gap 420b and the second airflow channel 430b. The arc gas is divided into two parts starting from the airflow gap 420, which is beneficial to improving the arc extinguishing performance.

[0047] Here, the first blocking portion 440a has a first inclined surface 440a1 or a first curved surface in the first airflow gap 420a, and the first inclined surface 440a1 or the first curved surface forms a first Laval nozzle 450a aligned with the first airflow channel 430a inside the first airflow gap 420a. The first Laval nozzle 450a here means that the size of the nozzle changes from large to small, specifically, it is the largest at the inlet end 4201, and becomes smaller at the outlet end 4202 or inside the first airflow gap 420a due to the first inclined surface 440a1 or the first curved surface.

[0048] Similarly, the second blocking portion 440b has a second inclined surface 420b1 or a second curved surface in the second airflow gap 420b, and the second inclined surface 420b1 or the second curved surface forms a second Laval nozzle 450b aligned with the second airflow channel 430b inside the second airflow gap 420b.

[0049] Such a Laval nozzle arrangement will help the arc gas in the first airflow gap 420a (second airflow gap 420b) to be collected and sprayed into the first airflow channel 430a (second airflow channel 430b), accelerating the movement of the arc gas and helping to improve the arc extinguishing performance.

[0050] The arc-extinguishing housing 400 includes an upper cover 401 and a bracket 402 .

[0051] The arc extinguishing grid 410 is fixed on the bracket 402. The bracket 402 is arranged with N grid installation grooves 4020 in sequence. An arc extinguishing grid 410 is arranged in each grid installation groove 4020, and a partition rib 4400 is provided between two adjacent grid installation grooves 4020. The first blocking portion 440a and the second blocking portion 440b mentioned above are both part of the partition rib 4400. Of course, it does not mean that the first blocking portion 440a and the second blocking portion 440b are part of the same partition rib 4400, but that the first blocking portion 440a and the second blocking portion 440b are part of different partition ribs 4400. Such a structure will make it easier to form the first blocking part 440a and the second blocking part 440b, and as long as the first blocking part 440a and the second blocking part 440b are installed on the grid installation groove 4020, the first blocking part 440a and the second blocking part 440b can block the corresponding airflow gap 420 from the airflow channel.

[0052] For the arc extinguishing grid 410, both sides of the arc extinguishing grid 410 have fixing protrusions 4111. The fixing protrusions 4111 here correspond to the clamping slots 4021 on the bracket 402 one by one. Since the clamping slots 4021 are connected to the grid installation slots 4020, as long as the arc extinguishing grid 410 is pressed into the grid installation slots 4020, the fixing protrusions 4111 can be clamped into the clamping slots 4021, and the installation of the arc extinguishing grid 410 is completed. The number of the clamping slots 4021 and the fixing protrusions 4111 here can also be one, and the fixing effect can also be achieved. This installation structure of the arc extinguishing grid 410 will make the installation of the arc extinguishing grid 410 very convenient.

[0053] The upper cover 401 is generally located on the upper part of the bracket 402. The upper cover 401 and the bracket 402 are plug-in connected. Of course, in addition to this, a snap-on method or other fastening methods with fasteners 601 can also be used.

[0054] The upper cover 401 has a main body 401a, and the main body 401a forms a disconnecting channel 401b, and the disconnecting channel 401b is located above the entry end 4201. The disconnecting channel 401b here means that the process from contact to separation of the first contact 301 and the second contact 302 is completed at the disconnecting channel 401b. Specifically, the first contact 301 has a first contact 301a, and the second contact 302 has a second contact 302a. Here, the first contact 301a is always in the disconnecting channel 401b, and the second contact 302a is at least partially in the disconnecting channel 401b when it is in the maximum separation position. Such a setting will be conducive to the arc gas generated during disconnection being in the disconnecting channel 401b, and will be conducive to entering the airflow gap 420 through each entry end 4201. As a more preferred method, the upper cover 401 is made of gas-generating material, so that gas can be generated when the first contact 301a and the second contact 302a are separated, which is conducive to forming air blowing.

[0055] In order to improve the arc extinguishing performance, a magnetic field is arranged around the first contact 301 and the second contact 302. The magnetic field here is completed by a magnetizing member 500. The circuit breaker here is an AC circuit breaker, so the magnetizing member 500 is an iron sheet. When it is a DC circuit breaker, the magnetizing member 500 is a permanent magnet.

[0056] The magnetizing component 500 here is embedded in the main body 401a, surrounding (half-surrounding) the disconnecting channel 401b. The magnetizing component 500 includes a first magnetic part 500a, a second magnetic part 500b and a third magnetic part 500c. The first magnetic part 500a and the second magnetic part 500b are respectively arranged on both sides of the separation path of the first contact 301a and the second contact 302a, and the third magnetic part 500c is arranged close to the first contact 301a. In this embodiment, the magnetizing component 500 is an integrated part, forming a continuous U-shaped magnetic field area, which will be conducive to the stretching of the disconnected arc and cooperate with the arc extinguishing grid 410 to extinguish the arc. Of course, an integrated part may not be used here, and the first magnetic part 500a and the third magnetic part 500c, and the second magnetic part 500b and the third magnetic part 500c are all in abutment relationship, so that a continuous U-shaped magnetic field area can also be formed.

[0057] There are many ways to fix the magnetizing component 500 , for example, it can be directly formed in the main body 401 a through an injection molding process (not removable).

[0058] It can also be installed in the main body 401a through an assembly structure. As a more preferred installation method, a bayonet 4010 is provided on the upper cover 401, and a clamping protrusion 5001 is provided on the first magnetic part 500a and the second magnetic part 500b, and a clamping fit is formed between the bayonet 4010 and the clamping protrusion 5001. Of course, in addition to this, other clamping methods can also be used. In this way, it can be ensured that the magnetizing component 500 and the upper cover 401 form an assembly structure, which is conducive to ensuring the stable installation of the magnetizing component 500.

[0059] Of course, the magnetizing component 500 is also fixed by the bracket 402. A magnetizing component installation groove 4011 is provided on the upper cover 401. The notch of the magnetizing component installation groove 4011 faces the bracket 402. The magnetizing component installation groove 4011 is located around the disconnecting channel 401b. The bracket 402 has an abutment portion 4022 extending into the magnetizing component installation groove 4011. The magnetizing component 500 is in the magnetizing component installation groove 4011 and abuts against the abutment portion 4022. In this way, the bracket 402 also plays a role in the installation of the magnetizing component 500, which can ensure that the magnetizing component 500 is in a suitable position.

[0060] Of course, the installation of the magnetizing component 500 does not need to have both of the above structures at the same time, and only one of the structures is also acceptable.

[0061] In this embodiment, the first contact 301 is a stationary contact, which includes a mounting portion 301b, a connecting portion, and a contact assembly portion 301d.

[0062] The mounting portion 301b is used to fasten with a fastener 601 (screw) and a nut 602. The nut 602 here is an insert nut 602, which is more suitable for explosion-proof circuit breakers. Of course, other nuts 602 can also be used here, or the fastener 601 can be directly fixed to the wall of the inner cavity 101 without using a nut 602. The upper cover 401 has a matching portion 401c below the first contact 301, and the matching portion 401c is located on one side of the main body 401a (it is integrated). The matching portion 401c has an avoidance groove 401d, and the operating part of the fastener 601 (the part for tool operation) is located in the avoidance groove 401d. Such a setting of the avoidance groove 401d can ensure that the structure between the mounting structure of the first contact 301 and the arc extinguishing housing 400 is more compact, saving space at the height of the inner cavity 101.

[0063] The contact assembly portion 301d is used for welding or riveting the first contact 301a.

[0064] The connecting part includes two arms, and both arms include a transverse section 301c1 and a longitudinal section 301c2, and the transverse section 301c1 and the longitudinal section 301c2 form an L shape; the transverse section 301c1 is connected to the mounting portion 301b, and the longitudinal section 301c2 is connected to the contact assembly portion 301d (the contact assembly portion 301d is connected in the middle of the two longitudinal sections 301c2). A notch 3010 is formed between the transverse sections 301c1 of the two arms, and a boss 401e is provided on the matching portion 401c, where the boss 401e extends into the notch 3010 and fits with the notch 3010. Such a design of the boss 401e and the notch 3010 is to ensure that there is a matching relationship between the first contact 301 and the arc extinguishing housing 400, which will be conducive to the first contact 301a stably extending into the disconnection channel 401b. At the same time, the design of the boss 401e can also protect the horizontal section 301c1 and prevent the arc from burning the horizontal section 301c1. The matching portion 401c also has two baffles 401f, which are respectively located in the interval between the two longitudinal sections 301c2 and the contact assembly portion 301d. The arrangement of the baffles 401f can effectively prevent the arc from burning the two longitudinal sections 301c2 during disconnection.

[0065] Of course, the number of arms in the above structure is two, and of course it can also be one, and the number of corresponding baffles 401f can also be reduced. And although the above structure takes the example of the first contact being a static contact, it does not exclude the case where the first contact is also a moving contact. In this case, it is equivalent to that the contact assembly part and the connecting part are rotatably connected, and the rest of the structure is still applicable.

[0066] An exhaust port 4001 is provided on one side of the arc extinguishing housing 400, and the exhaust port 4001 is formed by the upper cover 401 and the bracket 402. Specifically, the bracket 402 has an open portion 402a on one side of the last arc extinguishing grid 410, and the upper cover 401 has a shielding portion 401g covering the open portion 402a, and the shielding portion 401g shields a part of the open portion 402a to form the exhaust port 4001, and the first airflow channel 430a and the second airflow channel 430b are both connected to the exhaust port 4001.

[0067] The exhaust port 4001 here does not exhaust gas toward the outside of the circuit breaker, but exhausts gas toward the inner cavity 101, because the ions in the arc gas have been extinguished through the first airflow gap 420a, the first airflow channel 430a, the second airflow gap 420b, and the second airflow channel 430b, and the remaining airflow will not damage other components even if it enters the rest of the inner cavity 101 through the exhaust port 4001. Such a design of the exhaust port 4001 can allow the gas to be discharged from the arc extinguishing structure in time, which can reduce the possibility of the arc extinguishing structure being damaged due to excessive internal air pressure.

[0068] There is a sinking area 205 on the bottom plate 200, the dividing rib 210 is arranged in the sinking area 205, the arc extinguishing housing 400 is partially embedded in the sinking area 205 (groove structure), and the sinking area 205 is also a component of the first airflow channel 430a and the second airflow channel 430b. Specifically, the lower part of the bracket 402 is embedded in the sinking area 205. The setting of such a sinking area 205 can firstly move the arc extinguishing structure downward as a whole, so that the design margin of other components is more sufficient; secondly, it makes the connection between the arc extinguishing structure and the bottom plate 200 tighter, and improves the stability of the arc extinguishing structure; finally, the bottom plate 200 is injection molded, and such a sinking area 205 is also conducive to improving the airtightness of the first airflow channel 430a and the second airflow channel 430b.

[0069] For the installation of the arc extinguishing housing 100, a first guide portion 1011 is provided on the wall of the inner cavity 101, and the first guide portion 1011 extends to the inner cavity opening 101a. A second guide portion is provided on the arc extinguishing housing 400, and the second guide portion and the first guide portion 1011 form a guide structure for installing the arc extinguishing housing 400. Here, the second guide portion is the peripheral structure of the matching portion 401c, which is in an arc shape, and the first guide portion 1011 is an adapted groove, so that when installing the arc extinguishing structure, the matching portion 401c can be used to stick to the first guide portion 1011, and then the arc extinguishing structure can be pushed into place, which is conducive to the installation of the arc extinguishing structure.

[0070] Although the above structure exemplifies the arc extinguishing structure and the contact system structure of one pole space, the same structure can also be used for other poles.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0072] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An explosion-proof circuit breaker, characterized in that: A cover shell, wherein the cover shell has an inner cavity, and the bottom of the cover shell has an inner cavity opening; A bottom plate, fixed to the cover shell, used to close the inner cavity opening; The inner cavity includes at least one pole space, each pole space has a set of contact systems and an arc extinguishing structure; A contact system, comprising a first contact and a second contact, wherein the first contact and the second contact have a contact state and a separation state; An arc extinguishing structure is used to extinguish an arc generated when a first contact is separated from a second contact; the arc extinguishing structure comprises an arc extinguishing shell and N arc extinguishing grids, N≥3; all arc extinguishing grids are fixed on the arc extinguishing shell and stacked in sequence along a direction, an airflow gap exists between two adjacent arc extinguishing grids, and the number of airflow gaps is N-1; an end of the airflow gap close to the first contact and the second contact is an entrance end, and an end away from the first contact and the second contact is an exhaust end; the bottom plate and the arc extinguishing shell together form a first airflow channel and a second airflow channel, and the first airflow channel and the second airflow channel are separated from each other; the airflow gap is divided into two groups, namely a first airflow gap and a second airflow gap, the exhaust end of the first airflow gap is connected to the first airflow channel, and the exhaust end of the second airflow gap is connected to the second airflow channel.

2. An explosion-proof circuit breaker according to claim 1, characterized in that: It also includes a separating rib, a first blocking portion and a second blocking portion; the separating rib is fixed on the base plate or is an integral part with the base plate, and is used to separate the first airflow channel from the second airflow channel; the first blocking portion is fixed on the arc-extinguishing shell or is an integral part with the arc-extinguishing shell or is fixed on the base plate or is an integral part with the base plate, and the first blocking portion is in the first airflow gap, blocking the discharge end of the first airflow gap from the second airflow channel; the second blocking portion is fixed on the arc-extinguishing shell or is an integral part with the arc-extinguishing shell or is fixed on the base plate or is an integral part with the base plate, and the second blocking portion is in the second airflow gap, blocking the discharge end of the second airflow gap from the first airflow channel.

3. An explosion-proof circuit breaker according to claim 2, characterized in that: The first blocking portion has a first inclined surface or a first curved surface in the first airflow gap, and the first inclined surface or the first curved surface forms a first Laval nozzle aligned with the first airflow channel inside the first airflow gap; the second blocking portion has a second inclined surface or a second curved surface in the second gap, and the second inclined surface or the second curved surface forms a second Laval nozzle aligned with the second airflow channel inside the second airflow gap.

4. An explosion-proof circuit breaker according to claim 2, characterized in that: The arc-extinguishing shell includes a bracket, on which N grid installation grooves are arranged in sequence, a partition rib is provided between two adjacent grid installation grooves, and the first blocking portion and the second blocking portion are both part of the partition rib; the notch of the grid installation groove faces the bottom plate, at least one side of the grid installation groove has a clamping groove, the clamping groove is connected with the grid installation groove, the arc-extinguishing grid has a fixing protrusion adapted to the clamping groove, and the arc-extinguishing grid is installed from the notch until the fixing protrusion is clamped into the clamping groove.

5. An explosion-proof circuit breaker according to claim 1, characterized in that: The arc-extinguishing shell includes an upper cover and a bracket, the arc-extinguishing grid is arranged on the bracket, and the upper cover is arranged on the bracket; the upper cover has a main body, and a disconnecting channel is opened on the main body, and the disconnecting channel is located above the entrance end; the first contact includes a first contact point, and the second contact includes a second contact point, and the contact and separation of the first contact and the second contact are realized by the first contact point and the second contact point; the first contact point is always in the disconnecting channel, and at least a part of the second contact point is in the disconnecting channel when it is in the final position of the separation state.

6. An explosion-proof circuit breaker according to claim 5, characterized in that: A magnetizing component is embedded in the main body, and the magnetizing component includes a first magnetic part, a second magnetic part and a third magnetic part; the first magnetic part and the second magnetic part are respectively arranged on both sides of the separation path of the first contact and the second contact, and the third magnetic part is arranged close to the first contact; the first magnetic part and the third magnetic part, and the second magnetic part and the third magnetic part are all in abutment relationship, or the magnetizing component is an integrated part.

7. An explosion-proof circuit breaker according to claim 6, characterized in that: The upper cover and the magnetizing component are connected by a clamping arrangement; And / or, a magnetizing component installation groove is opened on the upper cover, the groove opening of the magnetizing component installation groove faces the bracket, the magnetizing component installation groove is located at the periphery of the separating channel, the bracket has an abutment portion extending into the magnetizing component installation groove, the magnetizing component is in the magnetizing component installation groove and abuts against the abutment portion.

8. An explosion-proof circuit breaker according to claim 5, characterized in that: The first contact is fixed to the inner cavity wall by a fastener or a nut in the inner cavity wall, and the first contact has a notch; the upper cover also includes a matching portion, which is located on one side of the main body and below the first contact; the matching portion is provided with an avoidance groove and a boss, one end of the fastener is in the avoidance groove, and the boss extends into the notch and fits with the notch.

9. An explosion-proof circuit breaker according to claim 5, characterized in that: The first contact comprises a contact assembly part and a connecting part, the contact assembly part and the connecting part are arranged at an interval, and the contact assembly part is used to install the first contact; the upper cover has a baffle, and the baffle is inserted into the interval between the contact assembly part and the connecting part.

10. An explosion-proof circuit breaker according to claim 1, characterized in that: The bottom plate has a sinking area, the arc-extinguishing housing is partially embedded in the sinking area, and the sinking area is a component of the first airflow channel and the second airflow channel; And / or, the arc-extinguishing housing has an exhaust port on one side of the last arc-extinguishing grid, and the first airflow channel and the second airflow channel are both connected to the exhaust port; And / or, the number of the first airflow gaps is at least two, and there is a second airflow gap between every two adjacent first airflow gaps; And / or, the number of the second airflow gaps is at least two, and there is a first airflow gap between every two adjacent second airflow gaps; And / or, all arc-extinguishing grids are arranged in a straight line direction or a curved line direction; And / or, a first guide portion is provided on the wall of the inner cavity, the first guide portion extends to the opening of the inner cavity, and a second guide portion is provided on the arc-extinguishing housing, and the second guide portion and the first guide portion form a guide structure for installing the arc-extinguishing housing; and / or, the bottom plate and the cover shell form a staggered structure, and the staggered structure surrounds the inner cavity opening; And / or, a glue-filling structure is provided between the bottom plate and the cover shell, and the glue-filling structure surrounds the inner cavity opening; And / or, in the height direction, the position of the contact system is higher than the position of the arc extinguishing grid.

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