Housing assemblies and electrical switching devices, particularly contactors or relays.

Abstract

To provide a contactor improved in safety and reliability.SOLUTION: The present invention relates to a housing assembly for a contactor. The housing assembly includes: a frame (4) made of a ferromagnetic material and surrounding a contact chamber for separable contacts of the contactor; and an enclosure (6) made of an insulative material and at least partially covering the frame (4) internally and externally. The enclosure (6) includes at least one pocket (52) for receiving a blow-out magnet (50) of the contactor. The frame (4) is at least partially exposed for contact in the at least one pocket (52). The frame (4) improves the mechanical stability of the housing assembly and offers a suitable path for conducting a magnetic flux from the blow-out magnet (50).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a housing assembly for an electrical switching device such as a contactor or a relay. Further, the present invention relates to an electrical switching device for high-voltage automotive applications, particularly a contactor or a relay. However, the scope of application of the present invention extends to other fields of electrical engineering as well.

Background Art

[0002] Generally, electrical switching devices such as contactors and relays are used in the field of electrical engineering to open and close electrical circuits. The purpose is to influence the flow of a relatively strong current using a relatively weak control current. In particular, the control current is used to join or separate separable contacts that conduct the flow of the strong current.

[0003] Especially in high-voltage applications, an electric arc may occur when interrupting the flow of a strong current. That is, an arc discharge may occur between separable contacts, which may cause damage to components such as melting of conductors, destruction of insulators, and arcing. In order to quickly extinguish the arc discharge, so-called blow-out magnets are often arranged near the separable contacts. These blow-out magnets are for generating a magnetic force that stretches the arc discharge and finally interrupts it.

[0004] However, even when using this arc elimination method or other types of arc elimination methods, an electric explosion generally known as an arc flash may occur, which may cause the electrical switching device to explode. For example, a short circuit in an electrical circuit for high-voltage applications may cause an excessive current flow. The resulting short-circuit current often causes a strong repulsive force between the separable contacts. When the separable contacts are separated from each other by the repulsive force, the resulting arc discharge generates an extremely high pressure and the above-mentioned arc flash. This is dangerous for people and equipment and needs to be prevented.

Summary of the Invention

[0005] Therefore, an object of the present invention is to improve the safety and reliability of contactors and other electrical switching devices. [Means for solving the problem]

[0006] This objective is achieved by a housing assembly of the type described above, the housing assembly comprising a frame formed of a ferromagnetic material surrounding a contact chamber for separable contacts of a contactor, and a casing formed of an insulating material at least partially covering the frame on the inside and outside. The casing may also be called an enclosure or shell. The casing includes at least one pocket for receiving a blow-off magnet for the contactor, and the frame is at least partially exposed for contact in at least one pocket.

[0007] The above solution is advantageous for at least two reasons.

[0008] Firstly, the frame provides a mechanical reinforcement structure to the entire housing assembly. Therefore, even if the housing assembly according to the present invention is used in a contactor or other type of electrical switching device and an arc flash occurs, the frame can effectively prevent or at least mitigate the explosion of the housing assembly. In particular, the housing assembly provides high safety in the event of a short circuit.

[0009] Secondly, the ferromagnetic material of the frame exhibits lower magnetic resistance compared to the air, plastic, or ceramic that typically surrounds the blow-off magnet in conventional switches. Therefore, in this invention, once the blow-off magnet is received in at least one pocket, the frame provides a suitable path for transmitting magnetic flux from the blow-off magnet. For this purpose, the frame is exposed in at least one pocket for contact by the blow-off magnet. In other words, the frame, by its exposure, is accessible by the blow-off magnet in at least one pocket.

[0010] This allows the magnetic field of the extinguishing magnet to propagate more effectively within the contact chamber. As a result, arc extinguishing is improved and the electric arc is shortened, which contributes to the safe and reliable operation of electrical switching devices using the housing assembly according to the present invention.

[0011] The present invention can be further improved by the following embodiments, which are advantageous in themselves and can be arbitrarily combined with one another.

[0012] According to one possible embodiment, at least one pocket may be adjacent to a frame. In other words, a portion of the frame may define one side of the pocket. This results in a compact structure, as at least one pocket and the frame are directly adjacent to each other.

[0013] Alternatively, a separation wall may separate the frame at least partially from at least one pocket. In this case, the separation wall preferably includes an access window through which the frame is exposed for contact with the blow-off magnet. Optionally, the frame and / or the blow-off magnet may include projections reachable through the access window. The access window allows the contact between the frame and the blow-off magnet to be concentrated at a specific location suitable for the respective application.

[0014] According to another embodiment that is easy to manufacture, the frame may have a polyhedral shape with at least one open face. For example, the frame may have an open box shape formed by five mutually perpendicular rectangular faces. Thus, the frame may be a deep-drawn metal part. Alternatively, the frame may be a stamped and bent part, a forged part, a die-cast part, or a 3D printed part.

[0015] At least one pocket and contact chamber may both open to the same face. In particular, at least one pocket and contact chamber may open to the same face as the polyhedral frame. This simplifies the assembly process of the switching device, with the blow-off magnets being received in at least one pocket and the separable contacts being placed in the contact chamber. Both assembly steps can be performed from the same direction, without the need to rotate or tilt the housing assembly.

[0016] In a further embodiment, the housing assembly may include a lid for closing only a portion of the contact chamber and at least one pocket. That is, the lid may have at least one relatively small opening through which the contact chamber communicates with the environment of the housing assembly. The size of the opening is selected so as to slow down the equalization of pressure between the inside and outside of the contact chamber. Therefore, when an electric arc occurs, the resulting high pressure is temporarily maintained within the contact chamber. Maintaining a high pressure for the duration of the arc discharge helps extinguish the arc.

[0017] Optionally, at least one edge of the frame may protrude from the enclosure. Furthermore, the housing assembly may include a base plate that can be welded to at least one protruding edge of the frame. Preferably, at least one protruding edge of the frame surrounds the contact chamber and at least one pocket. Correspondingly, the base plate can be welded to at least one edge. The lid can be positioned between the frame and the base plate. Thus, the base plate can mechanically reinforce the lid in the same way that the frame reinforces the enclosure.

[0018] Alternatively, if a separate cover or base plate is not provided, the housing assembly can be welded directly to the housing of the actuator, such as a solenoid or other type of coil assembly.

[0019] In another embodiment, the enclosure may include an inner wall covering the contact chamber internally and an outer wall enclosing the frame externally, with the frame positioned between the inner and outer walls. In other words, the frame is sandwiched between the inner and outer walls. This effectively isolates the frame from the separable contacts of the contact chamber, while simultaneously providing the frame with external touch protection.

[0020] To simplify the handling of the housing assembly, the frame and enclosure can be formed together as a single structure. In particular, in this embodiment, since the frame and enclosure are a single unit, no additional separate parts are required. For example, the inner and outer walls can be overmolded onto the frame. Thus, the inner wall is embodied by an inner layer of insulating material, and the outer wall is embodied by an outer layer of insulating material.

[0021] Optionally, the frame can include at least one through-hole leading to the contact chamber. During the overmolding process, a material laminate of an insulating material can be formed in at least one through-hole connecting the inner layer and the outer layer. This strengthens the connection between the frame and the enclosure.

[0022] Alternatively, the inner wall and the outer wall can be prefabricated elements attached to the frame. In particular, the prefabricated elements can be precast from an insulating material. According to this embodiment, the prefabricated elements can be replaced when needed, making maintenance easier.

[0023] It is also conceivable that only the inner wall or the outer wall is a prefabricated element attached to the frame, and each other wall is overmolded onto the frame.

[0024] The above-mentioned separation wall can be part of the enclosure. Furthermore, the separation wall can be embodied by a prefabricated element attached between the frame and the blow-out magnet, or by a separation layer of an insulating material inserted between the frame and the blow-out magnet.

[0025] According to another embodiment, at least one pocket can be formed by the inner wall. Thereby, the frame can surround the blow-out magnet received in at least one pocket. Therefore, the frame can function as a shield against the magnetic field of the blow-out magnet to some extent.

[0026] To increase the number of blow-out magnets that can be received by the housing assembly, it is preferable that the enclosure can include at least two pockets. This improves the arc extinguishing ability.

[0027] Optionally, at least two pockets can be arranged opposite to each other with respect to the contact chamber. In other words, the contact chamber can be arranged between at least two pockets. Therefore, the blow-out magnets can be arranged on at least both sides of the contact chamber, thereby improving the arc extinguishing effect.

[0028] The first described object can also be fulfilled by an electrical switching device, in particular a contactor, such as a DC contactor or an AC contactor, or a relay, wherein the switching device comprises a housing assembly according to any one of the above embodiments, a separable contact arranged in the contact chamber of the housing assembly, and a contact assembly comprising at least one blow-out magnet positioned within at least one pocket of the enclosure and in direct contact with the frame.

[0029] The switching device benefits from the technical effects and advantages of the above housing assembly. In particular, the safety and reliability of the switching device are improved by the presence of the housing assembly.

[0030] According to one possible embodiment, at least one blow-out magnet can be a permanent magnet, and the magnetic flux of at least one blow-out magnet can be transmitted through the frame. In addition to improving the propagation of the magnetic field into the contact chamber, this embodiment is advantageous because no separate fixing means for at least one blow-out magnet is required. The fixing function is automatically provided by the magnetic force between the permanent magnet and the ferromagnetic frame. It is preferred that one blow-out magnet is provided for each pocket of the housing assembly.

[0031] Furthermore, the back and / or side surfaces of each blowing magnet facing away from the contact chamber may be in direct contact with the frame. If two blowing magnets are provided, when the blowing magnets are positioned opposite each other to the contact assembly, the back and / or side surfaces of each will face away from the other blowing magnet. This results in so-called magnetic recombination of the blowing magnets, connecting their respective back and / or side surfaces via the frame.

[0032] Optionally, the switching device may include a coil assembly for acting on a contact assembly. The housing assembly and the contact assembly may be placed within the coil assembly. The plunger of the coil assembly may reach into the housing assembly. The plunger can transmit the actuation force and the resulting actuation from the coil assembly to the separable contacts of the contact assembly. Alternatively, manual actuation may be used.

[0033] Furthermore, the switching device can optionally be configured to have multiple connection points. Power cables can be provided for each connection point and fixed to the associated connection point for contact. In particular, the switching device may have multiple fixed elements, contact elements, and / or energizing elements at the connection points. The connection points are interconnected via contact assemblies and their separable contacts.

[0034] The present invention will be described in more detail below with reference to the drawings. The combination of features illustrated in the example embodiments may be supplemented by further features in accordance with the above description to match the characteristics of the present invention required for a particular application. If the effect of an individual feature is irrelevant to a particular application, that feature may be omitted in accordance with the above description of the embodiment. The same reference numerals in the figures are always used for elements having the same function and / or the same structure. [Brief explanation of the drawing]

[0035] [Figure 1] This is a schematic perspective view of a housing assembly according to an exemplary embodiment. [Figure 2] Figure 1 is another schematic perspective view of the housing assembly. [Figure 3] This is a schematic exploded perspective cross-sectional view of a housing assembly according to a further exemplary embodiment. [Figure 4] This is a schematic side cross-sectional view of an electrical switching device according to an exemplary embodiment. [Figure 5] This is a schematic side cross-sectional view of a housing assembly according to another exemplary embodiment. [Figure 6] This is a schematic exploded side cross-sectional view of a housing assembly according to another exemplary embodiment. [Figure 7] This is a schematic perspective view of the frame and bottom plate of a housing assembly according to a further exemplary embodiment. [Figure 8] Figure 5 shows another schematic cross-sectional view of the frame and base plate. [Modes for carrying out the invention]

[0036] The schematic structure of the housing assembly 1 and the electrical switching device 2 according to the present invention will be described below with reference to Figures 1 to 8.

[0037] As can be seen in the schematic perspective views of Figures 1 and 2, the housing assembly 1 comprises a frame 4 and a surrounding body 6 that at least partially encloses the frame 4 both internally and externally. The surrounding body 6 may also be called an enclosure or shell.

[0038] The housing assembly 1 is used for an electrical switching device 2, which may be, for example, a casing 6 or a relay 10. As will be described in more detail below, the housing assembly 1 can contribute to improving the safety and reliability of the electrical switching device 2.

[0039] In particular, the frame 4 provides a mechanical reinforcement structure to the entire housing assembly 1. That is, the frame 4 is formed from a ferromagnetic material, especially a ferromagnetic metal. For example, the frame 4 may be a deep-drawn metal part 12 (see Figure 6). Alternatively, the frame 4 may be a stamped and bent part, a forged part, a die-cast part, or a 3D printed part.

[0040] In the illustrated embodiment, the frame 4 may have an open box shape formed by five mutually perpendicular rectangular faces 14 (see Figure 7). More generally, the frame 4 may have a polyhedral shape with at least one open face. This shape allows the frame 4 to surround a contact chamber 16 for the separable contacts 18 of the contact assembly 20 of the switching device 2.

[0041] The separable contact 18 includes at least one fixed contact 22 and at least one movable contact 24, all of which exhibit high conductivity. For example, the movable contact 24 may be a contact bridge 26 stretched between two fixed contacts 22 located within the contact chamber 16 (see Figure 4).

[0042] The switching device 2 may include a coil assembly 28 for actinguating the contact bridge 26. The housing assembly 1 and the contact assembly 20 can be placed in the coil assembly 28. The plunger 30 of the coil assembly 28 can reach into the housing assembly 1. The plunger 30 can transmit the actuating force and the resulting actuating motion from the coil assembly 28 to the contact bridge 26. Alternatively, manual actuation may be used.

[0043] The enclosure 6 separates the frame 4 from the contact chamber 16. To this end, the enclosure 6 may be formed from an insulating material and may include an inner wall 32 that covers the contact chamber 16 from the inside. In particular, the inner wall 32 may be embodied by an inner layer 34 of insulating material overmolded onto the frame 4 (see Figure 5).

[0044] Furthermore, the enclosure 6 can provide external touch protection. Therefore, the enclosure 6 may include an outer wall 36 that encloses the frame 4 from the outside. Thus, the outer wall 36 can be embodied by an outer layer 38 of insulating material. Here again, the outer layer 38 can be overmolded onto the frame 4 (see Figure 5).

[0045] In other words, both the inner wall 32 and the outer wall 36 can be overmolded onto the frame 4. Thus, the frame 4 and the enclosure 6 can form a single integrated structure 40. Optionally, the frame 4 may include at least one through-hole 42 leading to the contact chamber 16. During the overmolding process, a laminate of insulating material 44 can close at least one through-hole 42 connecting the inner layer 34 and the outer layer 38.

[0046] According to the alternative embodiment shown in Figure 6, the inner wall 32 may be an assembly element 46 attached to the frame 4. Similarly, the outer wall 36 may be an assembly element 48 attached to the frame 4. Here, the frame 4 is positioned, and in particular, sandwiched, between the inner wall 32 and the outer wall 36.

[0047] The ferromagnetism of frame 4 can be further enhanced by combining it with the deactivating magnets 50 of the switching device 2. These deactivating magnets 50 are positioned near the separable contacts 18 to quickly extinguish any arc discharge that occurs between the fixed contacts 22 and the movable contacts 24. In particular, the deactivating magnets 50 generate a magnetic force that stretches and ultimately shuts off the arc discharge.

[0048] Because frame 4 exhibits lower magnetic resistance compared to the air, plastic, or ceramic that typically surrounds the extinguishing magnet in conventional switches (not shown), frame 4 provides a suitable path for transmitting magnetic flux from the extinguishing magnet. This allows the magnetic field of the extinguishing magnet 50 to propagate more effectively in the contact chamber 16, helping to extinguish the arc discharge.

[0049] To accommodate the blow-off magnets 50 of the switching device 2, the enclosure 6 includes one pocket 52 for each blow-off magnet 50. The frame 4 is at least partially exposed in these pockets 52 for contact by the corresponding blow-off magnets 50. In other words, the frame 4 is accessible by the blow-off magnets 50 in each pocket 52 by its exposure.

[0050] As shown in Figure 2, the pockets 52 may be adjacent to the frame 4. That is, a portion 54 of the frame 4 may define one face of each pocket 52. Alternatively, a separation wall (not shown) may separate the frame 4 at least partially from the corresponding pockets 52. In this case, the separation wall preferably includes an access window through which the frame is exposed for contact by the blow-off magnet. Optionally, the frame and / or the blow-off magnet may include projections that can be reached through the access window.

[0051] As can be seen further in Figure 2, both the pocket 52 and the contact chamber 16 may open to the same plane. In particular, both the pocket 52 and the contact chamber 16 may open to the same plane as the frame 4.

[0052] It is preferable that the pockets 52 be formed by the inner walls 32 (see Figure 6). This allows the frame 4 to surround the blow-off magnets 50 received in each pocket 52, as seen in Figure 4. Furthermore, the pockets 52 can be positioned opposite each other with respect to the contact chamber 16. In other words, the contact chamber 16 can be positioned between the pockets 52. Thus, the blow-off magnets 50 can be positioned on both sides of the contact chamber 16.

[0053] To close the contact chamber 16 and pocket 52, the housing assembly 1 may be provided with a lid 56 (see Figure 3). The lid 56 may be configured to cover most of the contact chamber 16 and pocket 52. Furthermore, the lid 56 may have at least one opening 58 through which the contact chamber 16 communicates with the environment of the housing assembly 1. The size of the at least one opening 58 is selected to slow down the equalization of pressure between the inside and outside of the contact chamber 16.

[0054] The plunger 30 of the coil assembly 28 may be connected in such a way that it reaches into the contact chamber 16 through the opening 58 of the lid 56 and transmits force and displacement to the contact bridge 26 (see Figure 4). This allows the operating force generated from the coil assembly 28 to be transmitted through the plunger 30 and move the contact bridge 26. If multiple contact bridges are provided, the plunger 30 of the coil assembly 28 can be connected to at least one of those contact bridges.

[0055] The lid 56 may be an assembled element 60 attached to the frame 4 and / or the enclosure 6. The lid 56 is preferably formed from an insulating material. As structural reinforcement of the lid 56, the housing assembly 1 may include a base plate 62 formed from a ferromagnetic material, particularly a ferromagnetic metal. The base plate 62 can be attached to the frame 4 and / or the enclosure 6. The lid 56 can be positioned between the frame 4 and the base plate 62.

[0056] Optionally, at least one edge 64 of the frame 4 can protrude from the enclosure 6 (see Figure 2). In this embodiment, the base plate 62 can be welded to the protruding edge 64 of the frame 4. Preferably, the protruding edge 64 of the frame 4 surrounds the contact chamber 16 and pocket 52. Correspondingly, the base plate 62 can be welded to the protruding edge 64 along the entire perimeter of the contact chamber 16 and pocket 52. Thus, the frame 4 and the base plate 62 together form a high-pressure resistant structure.

[0057] In an alternative embodiment (not shown), the housing assembly 1 can be directly welded to the housing of an actuator, such as a solenoid or other type of coil assembly. This eliminates the need for a separate cover or base plate.

[0058] Other methods for attaching the frame 4 to the base plate 62 or the actuator housing may include techniques such as bending, pressurizing, riveting, screwing, and bonding to establish a rigid connection.

[0059] As described above, the switching device 2 comprises a housing assembly 1 and a contact assembly 20 which includes a separable contact 18 located in the contact chamber 16 of the housing assembly 1 and an extinguishing magnet 50 positioned within a pocket 52 of the enclosure 6.

[0060] The blow-off magnets 50 are in direct contact with the frame 4. In particular, the back surface 66 of each blow-off magnet 50 facing away from the contact chamber 16 may be in direct contact with the frame 4. In addition or alternatively, the side surface 68 of each blow-off magnet 50 may be in direct contact with the frame 4. The blow-off magnets 50 may be permanent magnets 70, and it is preferable that their respective magnetic fluxes can be transmitted through the frame 4.

[0061] The base plate 62 can be positioned between the contact chamber 16 and the coil assembly 28 (see Figure 4). As mentioned above, the base plate 62 is ferromagnetic. This allows the base plate 62 to transmit the magnetic flux generated from the coil assembly 28, improving the operation of the coil assembly 28.

[0062] Furthermore, as shown in Figure 4, the switching device 2 can be configured to have a plurality of connection points 72, which can be optionally selected. Power cables (not shown) can be provided for each connection point 72 and fixed to the connection point 72. For this purpose, fixing elements (not shown) may be present at each connection point 72. Alternatively, each power cable can be welded or soldered to the connection point 72.

[0063] The connecting portion 72 can extend into the contact chamber 16 through the outer wall 36, the frame 4, and the inner wall 32 (see Figure 4). For this purpose, a suitable opening 74 can be provided in the outer wall 36, the frame 4, and / or the inner wall 32 (see Figure 6).

[0064] The end 76 of the connector 72 extending into the contact chamber 16 can function as the fixed contact 22. These fixed contacts 22 can be interconnected via a contact bridge 26. When the contact bridge 26 is separated from the fixed contacts 22 by the coil assembly, this interconnection is broken. The arc discharge generated during this separation process is extinguished by the blow-off magnet 50.

[0065] The electrical switching device 2, shown as the surrounding element 6, may be a DC contactor or an AC contactor. Alternatively, the present invention may be used in a relay 10 or a similar electrical switch. [Explanation of Symbols]

[0066] 1 Housing Assembly 2 Switching devices 4 frames 6. Encircling force 8 Contactor 10 Relays 12 parts 14 sides 16 Contact Chamber 18 separable contacts 20 Contact Assembly 22 Fixed contact 24 Movable Contact 26 Contact Bridge 28 Coil Assembly 30 plungers 32 Inner wall 34 Inner Layer 36 Exterior Wall 38 Outer layer 40 Monolithic structure 42 Through hole 44-Material Laminate 46 modular elements 48 modular elements 50 Blow Eraser Magnets 52 pockets 54 part 56 Lid 58 Opening 60 modular elements 62 Base Plate 64 Edge 66 Back side 68 Side view 70 Permanent Magnets 72 Connection part 74 Aperture 76 End

Claims

1. A housing assembly (1) for a contactor (8), wherein the housing assembly (1) is - A frame (4) made of a ferromagnetic material surrounds the contact chamber (16) for the separable contact (18) of the contactor (8), - A surrounding body (6) formed of an insulating material that covers the frame (4) at least partially on the inside and outside. Equipped with, The enclosure (6) includes at least one pocket (52) for receiving the blow-off magnet (50) of the contactor (8), The frame (4) is at least partially exposed for contact in the at least one pocket (52), The enclosing body (6) includes an inner wall (32) and an outer wall (36), the inner wall (32) covering the contact chamber (16) on its inside, and the outer wall (36) at least partially contacting the outside of the frame (4) and at least partially enclosing the outside of the frame (4). A housing assembly (1) wherein at least one edge (64) of the frame (4) protrudes from the outer wall (36) of the enclosing body (6), and the housing assembly (1) includes a base plate (62) that can be welded to the at least one edge (64) of the frame (4).

2. The housing assembly (1) according to claim 1, wherein the at least one pocket (52) is adjacent to the frame (4).

3. The housing assembly (1) according to claim 1, wherein the frame (4) has a polyhedral shape with at least one open face.

4. The housing assembly (1) according to claim 1, further comprising a lid (56) for partially closing the contact chamber (16).

5. The frame (4) has a first side which is at least partially exposed for contact in the at least one pocket (52), and a second side which is the opposite side of the first side, the second side being the outer side of the frame (4), The housing assembly (1) according to claim 1, wherein the outer wall (36) of the enclosing body (6) is at least partially in contact with the second side of the frame (4) and at least partially encloses the second side of the frame.

6. The housing assembly (1) according to claim 1, wherein the frame (4) is positioned between the inner wall (32) and the outer wall (36).

7. The housing assembly (1) according to claim 1, wherein the frame (4) and the surrounding body (6) form an integrated structure (40).

8. The housing assembly (1) according to claim 6, wherein the inner wall (32) and the outer wall (36) are overmolded onto the frame (4).

9. The housing assembly (1) according to claim 6, wherein the inner wall (32) and the outer wall (36) are prefabricated elements (46, 48) attached to the frame (4).

10. The housing assembly (1) according to claim 6, wherein the at least one pocket (52) is formed by the inner wall (32).

11. The housing assembly (1) according to claim 1, wherein the surrounding body (6) includes at least two pockets (52).

12. The housing assembly (1) according to claim 11, wherein the at least two pockets (52) are arranged opposite each other with respect to the contact chamber (16).

13. Switching device (2), A housing assembly (1) according to any one of claims 1 to 10, A contact assembly (28) including a separable contact (18) positioned in the contact chamber (16) of the housing assembly (1), and at least one blow-off magnet (50) positioned within the at least one pocket (52) of the enclosing body (6) and in direct contact with the frame (4), and A switching device (2) comprising the above.

14. The switching device (2) according to claim 13, wherein the at least one blow-off magnet (50) is a permanent magnet (70), and the magnetic flux of the at least one blow-off magnet (50) is transmitted through the frame (4).

15. The switching device (2) according to claim 13, wherein the back surface (66) of each blowing magnet (70) facing away from the contact chamber (16) is in direct contact with the frame (4).

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