Breaking unit and electrical device comprising breaking unit

Abstract

The invention provides a breaking unit. The breaking unit comprises a shell, a contact chamber, a main air channel and a backflow air channel. The contact chamber is provided with a moving contact which can be contacted with and disconnected from the static contact. The arc extinguish chamber is provided with arc extinguish grid sheets used for extinguishing electric arcs generated when the static contact and the moving contact are disconnected. One end of the main air passage is communicated with the arc extinguish chamber at one side, facing the moving contact, of the arc extinguish chamber, and the other end of the main air passage is communicated with the contact chamber, so that air flow generated when the static contact and the moving contact are disconnected flows to the arc extinguish chamber through the main air passage; and one end of the backflow air passage is communicated with the arc extinguishing chamber at one side, deviating from the moving contact, of the arc extinguishing chamber, and the other end of the backflow air passage is communicated with the contact chamber through an outlet of the backflow air passage, so that air flow flowing through the arc extinguishing grid plate flows back to the contact chamber through the backflow air passage. And a gas flow path formed by the contact chamber, the arc extinguish chamber, the main gas channel and the backflow gas channel is not communicated with the outside of the shell. The invention further provides an electrical device comprising the breaking unit.

Description

Technical Field

[0001] The present disclosure relates to the electrical field, and in particular to a disconnecting unit and an electrical device including the disconnecting unit. Background Art

[0002] The main structure of a circuit breaker includes a moving contact and a stationary contact. The circuit breaker can drive the moving contact to separate from the stationary contact. During this process, the voltage between the moving contact and the stationary contact will break through the air and generate an arc. In order to prevent the arc from damaging the circuit breaker, an arc extinguishing device is generally installed in the circuit breaker.

[0003] When the contacts are disconnected, the arc generated between the moving and static contacts moves toward the arc extinguishing chamber under the action of magnetic blowing and / or air blowing, which will cause an air pressure difference between the arc extinguishing chamber and the position of the moving contact. This air pressure difference will cause the arc to retreat, hindering the arc from moving toward the arc extinguishing grid, which is not conducive to arc extinguishing.

[0004] However, even when the circuit breaker interrupts the arc, arc flashes may still be discharged from the exhaust port. If the arc flashes contact nearby electrical products or cabinet components, it may cause a short circuit, leading to serious equipment damage. To address this problem, existing technologies typically require the installation of a terminal shield at the exhaust port to provide enhanced protection and prevent serious consequences. However, installing a terminal shield significantly increases the overall space required, which conflicts with the increasing trend towards compact and miniaturized cabinets.

[0005] Therefore, a disconnecting structure that avoids arcing, has a strong arc extinguishing capability and a compact structure is needed. Summary of the Invention

[0006] The purpose of the present disclosure is to at least address the shortcomings of the prior art. The present disclosure proposes a disconnecting unit, comprising a housing, a contact chamber, a main air duct, and a return air duct. The contact chamber is provided with a movable contact capable of contacting and disconnecting with a static contact; the arc extinguishing chamber is provided with an arc extinguishing grid for extinguishing the arc generated when the static and movable contacts are disconnected; one end of the main air duct is connected to the arc extinguishing chamber on the side of the arc extinguishing chamber facing the movable contact, and the other end is connected to the contact chamber, so that the airflow generated when the static and movable contacts are disconnected flows through the main air duct to the arc extinguishing chamber; one end of the return air duct is connected to the arc extinguishing chamber on the side of the arc extinguishing chamber facing away from the movable contact, and the other end is connected to the contact chamber through a return air duct outlet, so that the airflow flowing through the arc extinguishing grid flows back to the contact chamber through the return air duct.

[0007] According to the embodiments of the present disclosure, a clever air duct arrangement increases the length of the airflow, effectively cooling it. This cooled airflow reduces arcing between the moving and static contacts. Furthermore, the airflow replenishes the air pressure in the contact chamber, stabilizing the pressure difference between the arc extinguishing chamber and the contact chamber, reducing arc backflow and improving arc extinguishing performance. Because this air duct arrangement significantly improves arc extinguishing capability, arcing issues can be resolved regardless of whether the airflow is exhausted outside the disconnecting unit.

[0008] Furthermore, for example, according to some embodiments of the present disclosure, the gas flow path formed by the contact chamber, the arc extinguishing chamber, the main gas duct, and the return gas duct is not in communication with the exterior of the housing. In particular, the housing does not have an exhaust port in communication with the gas flow path formed by the contact chamber, the arc extinguishing chamber, the main gas duct, and the return gas duct.

[0009] Because the air duct arrangement described above is sufficient to extinguish arcs within a sealed environment, there's no need to exhaust the airflow outside the disconnect unit, completely eliminating the risk of arcing. Furthermore, since there's no need to exhaust the gas within the disconnect unit, the gas flow path is isolated from the outside world, eliminating the need for an exhaust port and, consequently, the need for protective structures such as terminal covers. This significantly reduces the size of the disconnect unit or the electrical device containing it.

[0010] For example, according to some embodiments of the present disclosure, a flow blocking portion is provided on the return air duct, and the flow blocking portion is configured to block air flow from the contact chamber to the arc extinguishing chamber through the return air duct.

[0011] For example, according to some embodiments of the present disclosure, the flow blocking portion is configured to guide the airflow flowing from the contact chamber to the arc extinguishing chamber to be at least partially reversed.

[0012] For example, according to some embodiments of the present disclosure, the obstruction is arranged on a side of the return air duct away from the main air duct and / or a side close to the main air duct, the obstruction has a concave profile, one end of the obstruction close to the return air duct outlet is tangent to the return air duct, and the other end of the obstruction forms an angle less than ninety degrees with the return air duct.

[0013] For example, according to some embodiments of the present disclosure, at least one blocking portion is provided on each of a side of the return air duct away from the main air duct and a side of the return air duct close to the main air duct.

[0014] For example, according to some embodiments of the present disclosure, at least one of the obstructions is adjacent to and opposite to the outlet of the return air duct.

[0015] For example, according to some embodiments of the present disclosure, the breaking unit has two pairs of static contacts and moving contacts, and a corresponding arc extinguishing chamber, a main air duct, and a return air duct are provided for each pair of moving contacts and static contacts.

[0016] For example, according to some embodiments of the present disclosure, a corresponding first arc extinguishing chamber, a first main air duct and a first return air duct are set for the first moving contact and the first static contact, and a corresponding second arc extinguishing chamber, a second main air duct and a second return air duct are set for the second moving contact and the second static contact, the first main air duct is aligned with the second main air duct, and the first return air duct and the second return air duct are located on the same side relative to the first main air duct and the second main air duct.

[0017] For example, according to some embodiments of the present disclosure, there are two return air ducts corresponding to each pair of static contacts and moving contacts, which are respectively arranged on opposite sides of the main air duct and connected to the same arc extinguishing chamber and contact chamber.

[0018] The present disclosure further provides an electrical device, comprising the disconnecting unit according to any one of the embodiments of the present disclosure.

[0019] For example, according to some embodiments of the present disclosure, the electrical device is a circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A plan view showing the structure inside the housing of the disconnecting unit according to an embodiment of the present disclosure from a first perspective;

[0021] Figure 2 A schematic diagram showing a portion of a breaking unit according to an embodiment of the present disclosure from a second viewing angle;

[0022] Figure 3 A schematic diagram illustrating a breaking unit according to another embodiment of the present disclosure from a second viewing angle;

[0023] Figure 4 A schematic diagram of a breaking unit according to yet another embodiment of the present disclosure is shown from a second viewing angle.

[0024] Reference numerals

[0025] 1 housing, 11 static contacts,

[0026] 2 contact chambers, 21 moving contacts,

[0027] 3 arc extinguishing chambers, 31 arc extinguishing grids

[0028] 4 main airways,

[0029] 5 return airway, 51 return airway outlet,

[0030] 6. choke part,

[0031] D1 first direction, D2 second direction DETAILED DESCRIPTION

[0032] In order to make the purpose, scheme and advantages of the technical solution of the present disclosure more clear, the technical solution of the embodiment of the present disclosure will be clearly and completely described below in conjunction with the drawings of the specific embodiments of the present disclosure. Unless otherwise specified, the terms used herein have the common meanings in the art. The same reference numerals in the drawings represent the same components.

[0033] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on the specific circumstances.

[0034] For the convenience of explanation, in this disclosure, the first direction D1 is designated as Figure 1-4 The direction of the pivot axis of the movable contact of the breaking unit shown in FIG. 1 is the direction of extension of the main airway. In particular, the first direction D1 is perpendicular to the second direction D2. Figure 2-Figure 4 As shown by the arrow in .

[0035] Figure 1 The structural arrangement in the housing 1 of an embodiment of the breaking unit according to the present disclosure is shown as follows. Figure 1 As shown, the breaking unit according to the present disclosure includes a housing 1, in which a moving contact 21 and a stationary contact 11 are arranged. The moving contact 21 can move relative to the stationary contact 11, for example, by Figure 1 The housing 1 is pivotally connected to the housing 1 and pivotally moves to achieve contact and disconnection with the static contact 11. In particular, a contact chamber 2 (such as Figure 2 As shown), the moving contact 21 can be arranged in the contact chamber 2, and can perform contact and disconnection operations with the static contact 11 in the contact chamber 2.

[0036] The moving contact 21 and the stationary contact 11 can be as follows Figure 1 The two pairs of movable contacts 21 and the stationary contacts 11 are symmetrically arranged, and synchronous contact and disconnection are achieved through the synchronous pivoting of the two movable contacts 21 .

[0037] Figure 1The arrangement of the movable and stationary contacts is merely exemplary. The present disclosure may also include other configurations of movable and stationary contacts, such as, but not limited to, a translational movable contact structure and a single-pair contact structure. These structures are also compatible and usable in combination with the arc extinguishing chamber, main air duct, return air duct, and flow blocking structure described below.

[0038] The breaking unit according to the present disclosure may further include arc extinguishing grids 31. In particular, a corresponding arc extinguishing grid group is provided for each pair of moving contacts 21 and stationary contacts 11. Figure 1 Each set of arc quenching grids 31 can be arranged in a corresponding arc quenching chamber 3 (such as Figure 2 As shown in FIG, the arc extinguishing chamber 3 is respectively arranged close to a pair of corresponding moving contacts 21 and static contacts 11, and is separated by the moving contacts 21. Figure 1 As shown, the number of arc extinguishing grids 31 in the two groups is different and can be as follows: Figure 1 The parallel arrangement shown is in a row, in particular, can be aligned with each other (such as Figure 1 ), or arrangements that are not completely aligned with each other (such as Figure 1 Each set of arc-extinguishing grids 31 is used to extinguish the arc generated when the static contact 11 and the moving contact 21 are disconnected. In addition, the disconnecting unit may also be provided with arc-strike plates (not shown) that facilitate directing the arc toward the arc-extinguishing grids 31 to enhance the arc-extinguishing effect.

[0039] The breaking unit may also include a main airway 4, such as Figure 1 and Figure 2 As shown, the main gas channel 4 is connected to the contact chamber 2 and the arc extinguishing chamber 3. In particular, Figure 2 As shown, the main air channel 14 is connected to the arc extinguishing chamber 3 on the side of the arc extinguishing chamber 3 facing the moving contact 21. When the static contact 11 and the moving contact 21 are disconnected, the airflow generated by the main air channel 4 flows to the arc extinguishing chamber 3, thereby guiding the arc to the arc extinguishing grid in the arc extinguishing chamber 3.

[0040] In addition, the breaking unit according to the present disclosure may further include a return air channel 5, such as Figure 2 As shown, one end of the return air duct 5 connects to the arc extinguishing chamber 3 on the side of the arc extinguishing chamber 3 facing away from the moving contact 21, and the other end connects to the contact chamber 2, specifically through a return air duct outlet 51. This return air duct outlet 51 can be in the form of a narrow slit, for example. The additional return air duct increases the flow length of the airflow, thereby greatly improving the cooling effect of the airflow. The cooled airflow can reduce arc breakdown between the moving and static contacts.

[0041] Since the main air channel 4 and the return air channel 5 are respectively arranged on the opposite sides of the arc extinguishing chamber 3, the airflow generated when the static contact 11 and the moving contact 21 are disconnected flows through the main air channel 4 to the arc extinguishing chamber 3 and flows through the arc extinguishing grid 31, and can further flow back to the contact chamber 2 through the return air channel 5. The flow route is as follows: Figure 2 As shown by the black dotted arrow in the figure, a complete airflow loop is formed. As a result, the airflow returns to the contact chamber 2 to replenish the reduced air pressure in the contact chamber 2 caused by the gas overflowing into the main air duct 4, thereby stabilizing the air pressure difference between the arc extinguishing chamber 3 and the contact chamber 2, reducing arc backflow, improving the arc extinguishing performance of the breaking unit, and solving the arc flashover problem.

[0042] Furthermore, since the arrangement of the gas passages within the disconnecting unit is sufficient to achieve arc extinguishing, especially in a closed environment, there is no need to discharge the airflow outside the disconnecting unit. Therefore, for example, the gas flow path formed by the contact chamber 2, the arc extinguishing chamber 3, the main gas passage 4, and the return gas passage 5 may not be connected to the outside of the housing. In particular, there may be no exhaust port on the housing that is connected to the gas flow path formed by the contact chamber 2, the arc extinguishing chamber 3, the main gas passage 4, and the return gas passage 5. As a result, the problem of arcing is completely eliminated. In addition, since there is no need to exhaust the gas within the disconnecting unit and there is no need to set up protective structures such as terminal covers, the volume of the disconnecting unit or the electrical device including the disconnecting segment can be greatly reduced.

[0043] But similarly, the present disclosure may also include an arrangement with an exhaust port, which can be flexibly adjusted according to the actual model. However, due to the above-mentioned gas flow path arrangement according to the present disclosure, there will be no arcing discharged from the exhaust port.

[0044] like Figure 2 As shown, the disconnecting unit according to the present disclosure may further include a flow blocker 6, which may be provided on the return air duct 5 and configured to block the airflow from the contact chamber 2 to the arc extinguishing chamber 3 through the return air duct 5. By providing the flow blocker 6, the airflow in the return air duct 5 that flows in the opposite direction to the return airflow from the arc extinguishing chamber 3 to the contact chamber 2 is reduced, so that the return airflow from the arc extinguishing chamber 3 to the contact chamber 2 is more efficient, thereby greatly improving the disconnecting performance.

[0045] The flow blocking portion 6 may be, for example, a one-way valve, a one-way air-permeable membrane, etc., so as to directly allow only the airflow from the arc extinguishing chamber 3 to the contact chamber 2 to pass through.

[0046] In addition, the flow blocking portion 6 can also be a flow guiding component with a special structure, in particular, a flow guiding component configured to guide the airflow from the contact chamber 2 to the arc extinguishing chamber 3 to at least partially reverse the direction, and the airflow is guided to perform at least a partially reversed process. Figure 2 The black curved arrows in the figure schematically illustrate this. Consequently, this reverse flow guidance structure creates significant resistance to airflow from the contact chamber 2 to the arc extinguishing chamber 3, particularly significantly greater than the resistance experienced by airflow returning from the arc extinguishing chamber 3 to the contact chamber 2. This effect is hereinafter referred to as the flow resistance effect. Furthermore, the cost of installing this flow guidance structure is significantly lower than that of a one-way valve, and in particular, it can be integrally formed on the housing, reducing assembly steps.

[0047] Furthermore, if Figure 2 As shown, the flow blocking portion 6 may have a concave profile, which may be a curved profile, a multi-segment straight profile, or a combination of the two. Specifically, one end of the flow blocking portion 6 close to the return air duct outlet 51 is tangent to the return air duct 5, and the other end of the flow blocking portion 6 away from the return air duct outlet 51 forms an angle less than 90 degrees with the return air duct 5. In this way, the airflow from the contact chamber 2 to the arc extinguishing chamber 3 can be guided to at least partially reverse direction, as shown in FIG. Figure 2 As schematically shown by the black curved arrow in the middle, the smaller the angle between the other end of the flow blocking portion 6, away from the return air duct outlet 51, and the return air duct 5, the higher the efficiency of reverse flow guidance. Furthermore, the flow blocking portion 6 has almost no effect on the airflow returning from the arc extinguishing chamber 3 to the contact chamber 2, resulting in the airflow from the contact chamber 2 to the arc extinguishing chamber 3 encountering much greater resistance than the airflow returning from the arc extinguishing chamber 3 to the contact chamber 2.

[0048] like Figure 2 As shown, the flow blocking portion can be provided on the side of the return air duct 5 away from the main air duct 4 and / or on the side close to the main air duct 4. In particular, at least one flow blocking portion 6 is provided on each side of the return air duct 5 away from the main air duct 4 and close to the main air duct 4, as shown in FIG. Figure 2 In particular, at least one of the blocking portions 6 is adjacent to and opposite to the return airway outlet 51, and the blocking portion 6 provided therein has the best blocking effect. Figure 2 As shown, there are two flow-blocking portions 6, one located on the side of the return air duct 5 away from the main air duct 4 and the other located on the side close to the main air duct 4, and both are adjacent to and opposite to the return air duct outlet 51. Furthermore, additional flow-blocking portions 6 may be provided in other parts of the return air duct 5 to further enhance the flow-blocking effect.

[0049] like Figure 1 and 3 As shown, the breaking unit of the present disclosure may have two pairs of static contacts 11 and moving contacts 21. Therefore, a corresponding arc extinguishing chamber 3, main air duct 4, return air duct 5 and flow blocking portion 6 may be provided for each pair of moving contacts 11 and static contacts 21, as shown in FIG. Figure 3 As shown, in order to increase the arc extinguishing performance of the breaking unit.

[0050] In particular, corresponding first arc extinguishing chambers 3a, first main gas channels 4a and first return gas channels 5a (located at Figure 3 ), a corresponding second arc extinguishing chamber 3b, a second main gas channel 4b and a second return gas channel 5b are provided for the second moving contact and the second static contact (not shown) (for example, located at Figure 3The first main air channel 4a and the second main air channel 4b are aligned along the second direction D2 and are located on opposite sides of the contact chamber 2 in the second direction D2. The first return air channel 5a and the second return air channel 5b are located on the same side relative to the first main air channel 4a and the second main air channel 4b in the first direction D1. Figure 3 This makes the structure of the segmentation unit more compact, and in particular, makes the size in the first direction D1 smaller.

[0051] Furthermore, if Figure 4 In another embodiment shown, the number of return air ducts 5 corresponding to each pair of static contacts 11 and moving contacts 21 is two, for example, Figure 4 Two return airways on the left side 5 or Figure 4 Two return air ducts 5 on the right side of the middle. The two return air ducts 5 corresponding to the same pair of static contacts 11 and movable contacts 21 (for example, the two return air ducts 5 on the left side of the figure) can be respectively arranged on opposite sides of the main air duct 4 in the first direction D1 and connect the same arc extinguishing chamber 3 and contact chamber 2. The additional return air duct 5 can further increase the efficiency of the airflow returning from the arc extinguishing chamber 3 to the contact chamber 2 and enhance the cooling effect on the airflow.

[0052] The present disclosure also provides an electrical device (not shown) including the aforementioned disconnect unit. The electrical device may be, for example, a contactor, a circuit breaker, or the like. The electrical device may include one, two, three, four, or other disconnect units. For example, in a three-phase AC circuit, each disconnect unit is connected to a different phase in the corresponding circuit and / or ground. In a single-phase circuit, one disconnect unit is connected to each of the neutral and live wires, or only one disconnect unit is connected to the live wire.

[0053] It should be understood that the above description is intended to illustrate rather than to limit. For example, the above embodiments (and / or aspects thereof) may be used in combination with each other. In addition, without departing from the scope of the present disclosure, many modifications may be made to adapt specific circumstances or materials to the teachings of the present disclosure. The functions or performances of the various elements or modules described herein are intended to be illustrative only and are by no means restrictive, but are merely exemplary embodiments. After reading the above description, many other embodiments and modifications within the spirit and scope of the claims will be apparent to those skilled in the art. Therefore, the scope of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents given by these claims.

[0054] In the following claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

Claims

1. A breaking unit comprising case, The contact chamber is equipped with a moving contact that can contact and disconnect with the static contact. The arc extinguishing chamber is equipped with arc extinguishing grids to extinguish the arc generated when the static contact and the moving contact are disconnected. A main air duct, one end of which is connected to the arc extinguishing chamber on the side of the arc extinguishing chamber facing the moving contact, and the other end of which is connected to the contact chamber, so that the airflow generated when the static contact and the moving contact are disconnected flows to the arc extinguishing chamber through the main air duct, A return air duct, one end of which is connected to the arc extinguishing chamber on a side of the arc extinguishing chamber away from the moving contact, and the other end of which is connected to the contact chamber through a return air duct outlet, so that the airflow flowing through the arc extinguishing grid flows back to the contact chamber through the return air duct.

2. The breaking unit according to claim 1, wherein: The gas flow path formed by the contact chamber, the arc extinguishing chamber, the main gas channel and the return gas channel is not communicated with the outside of the shell.

3. The breaking unit according to claim 2, wherein: The housing does not have an exhaust port connected to the gas flow path formed by the contact chamber, the arc extinguishing chamber, the main gas channel and the return gas channel.

4. The breaking unit according to claim 1, wherein: The return air passage is provided with a flow blocking portion, and the flow blocking portion is configured to block the air flow from the contact chamber to the arc extinguishing chamber through the return air passage.

5. The breaking unit according to claim 4, wherein: The flow blocking portion is configured to guide the airflow flowing from the contact chamber to the arc extinguishing chamber at least partially in the reverse direction.

6. The breaking unit according to claim 5, wherein: The obstruction is arranged on a side of the return air duct away from the main air duct and / or on a side close to the main air duct, and the obstruction has a concave profile. One end of the obstruction close to the return air duct outlet is tangent to the return air duct, and the angle between the other end of the obstruction and the return air duct is less than ninety degrees.

7. The breaking unit according to claim 6, wherein: At least one flow blocking portion is respectively provided on a side of the return air duct away from the main air duct and a side close to the main air duct.

8. The breaking unit according to claim 7, wherein: At least one of the blocking portions is adjacent to and opposite to the return air duct outlet.

9. The breaking unit according to any one of claims 1 to 8, wherein: The breaking unit has two pairs of static contacts and moving contacts, and a corresponding arc extinguishing chamber, a main air duct and a return air duct are provided for each pair of moving contacts and static contacts.

10. The breaking unit according to claim 9, wherein: A first arc extinguishing chamber, a first main air duct and a first return air duct are provided for the first moving contact and the first static contact, and a second arc extinguishing chamber, a second main air duct and a second return air duct are provided for the second moving contact and the second static contact. The first main air duct is aligned with the second main air duct, and the first return air duct and the second return air duct are located on the same side relative to the first main air duct and the second main air duct.

11. The breaking unit according to any one of claims 1 to 8, wherein: There are two return air passages corresponding to each pair of static contacts and moving contacts, which are respectively arranged on opposite sides of the main air passage and communicate with the same arc extinguishing chamber and contact chamber.

12. An electrical device comprising the disconnect unit according to any one of claims 1 to 11.

13. The electrical device according to claim 12, wherein: The electrical device is a circuit breaker.

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