Switching device

Abstract

Switching device (100), comprising at least two contacts (1) in a switching chamber (11), wherein the at least two contacts comprise a fixed contact (2) and a movable contact (4), wherein each of the contacts on a contact side (20, 40) has a contact surface (21, 41) with at least one contact area (22, 42) and wherein at least the movable contact (4) has at least one return step (50).

Description

[0001] A switching device is specified.

[0002] The switching device is designed, in particular, as an electromagnetically operated, remotely controlled switch that can be operated by an electrically conductive current. The switching device can be activated via a control circuit and can switch a load circuit. In particular, the switching device can be designed as a relay or as a contactor, especially as a power contactor. Particularly preferably, the switching device can be designed as a gas-filled power contactor.

[0003] One possible application of such switching devices, in particular power contactors, is the opening and disconnecting of battery circuits, for example in motor vehicles such as electrically or partially electrically powered vehicles or in applications in the field of renewable energies.

[0004] Switching devices are described in the publications DE 10 2019 106 832 A1 and DE 10 2016 121 345 A1.

[0005] In its function as a safety component, a contactor is typically used in combination with a fuse between a battery, such as a lithium-ion battery, and an electric motor, and must be able to disconnect the power source from the load in the event of a malfunction. Currently, such systems are typically operated at voltages of around 450 V. In the next generation of such systems, the voltage can reach up to 800 V. Furthermore, in specialized applications, for example, voltages of up to 1500 V DC are required.

[0006] The higher the electrical voltage of the application, the greater the challenges placed on the contactor's design, as it must interrupt high currents at these high voltages in the event of a fault. Furthermore, it is required that the electrical parameters of the switching device remain close to their original or new state even after disconnecting high loads. This applies particularly to the contact resistance of the switching device, which is a major factor in the heating of the entire device during normal operation and has a significant impact on its subsequent performance and service life.

[0007] If the contacts of the switching device are separated under load, i.e., current flowing, arcs are created that can damage the contact surfaces by melting. This damage means that the contact surfaces can no longer make optimal contact and that the contact resistance increases when the device is reconnected.

[0008] To remove arcs from the contact areas as quickly as possible and to lengthen the arc path, so-called arc blowers are typically used. These deflect the arcs in specific directions depending on the current direction. For example, suitable switching chamber geometries and magnet arrangements can be used to deflect arcs in predetermined directions. Depending on the design, this can even occur independently of the current direction. Thus, depending on the magnetic deflection configuration and, if applicable, the current flow direction, arcs can be pushed to different sides of the contacts or adhere to different areas of the contacts. Consequently, irregularities can develop at different locations, which can lead to wear and an increase in contact resistance.It is also known to design a movable contact so short that it only covers about half of the fixed contacts. However, this design can lead to arcs causing damage far to the outer edges of the fixed contacts, damage that is not located in the actual contact area when the contact is re-closed. This mechanism does not prevent damage to the movable contact itself, which can indeed affect the contact resistance when the contact is re-closed. A further disadvantage is a reduced contact area, which can lead to reduced heat dissipation and increased local heating.

[0009] At least one function of certain embodiments is to specify a switching device.

[0010] This problem is solved by the subject matter according to the independent patent claim. Advantageous embodiments and further developments of the subject matter are characterized in the dependent claims and are further described in the following description and drawings.

[0011] According to at least one embodiment, a switching device has at least two contacts, which can also be referred to as the first and second contact, wherein one of the contacts is a fixed contact and the other of the contacts is a movable contact. Accordingly, the switching device has at least one fixed contact and at least one movable contact. The at least one fixed contact and the at least one movable contact are designed and configured to switch a load circuit connectable to the switching device on and off.

[0012] According to at least one further embodiment, one of the contacts, which can also be referred to as the first contact, has at least one contact area. The first contact can, for example, be a fixed contact of the switching device. Alternatively, the first contact can be a movable contact of the switching device. The first contact is designed and configured to establish a galvanic connection with a further contact, which can also be referred to as the second contact, when the contacts are in a suitable position relative to each other. In particular, the second contact can also have a contact surface with a contact area, so that the contact area of ​​the first contact and the contact area of ​​the second contact come into mechanical contact with each other when the contacts are in a suitable position relative to each other, and are thus galvanically connected.In particular, each of the contacts can have a contact page with at least one contact area.

[0013] The movable contact in the switching device is movable between a non-conducting state and a conducting state such that, in the non-conducting state, the movable contact is spaced apart from the at least one fixed contact and thus galvanically isolated, and in the conducting state, it has mechanical contact with the at least one fixed contact and is thus galvanically connected to it. The mechanical contact between the movable contact and the fixed contact in the conducting state can, in particular, be between a contact area of ​​the movable contact and a contact area of ​​the fixed contact.Particularly preferably, the switching device has at least two fixed contacts which are arranged separately from each other in the switching device and which in this way can be electrically connected to each other or electrically separated from each other depending on the state of the movable contact.

[0014] According to a further embodiment, the switching device has a housing in which the contacts, i.e., the at least one movable contact and the at least one fixed contact or the at least two fixed contacts, are arranged. The movable contact can, in particular, be arranged entirely within the housing. The fact that a fixed contact is arranged within the housing can, in particular, mean that at least the contact area of ​​the fixed contact, which is in mechanical contact with the movable contact in the switching state, is located within the housing. For connecting a supply line of a circuit to be switched by the switching device, a fixed contact arranged within the housing can be electrically contactable from the outside, i.e., from outside the housing.For this purpose, a fixed contact arranged inside the housing can protrude from the housing with a part and have a connection point for a supply line outside the housing.

[0015] According to a further embodiment, the contacts of the switching device are arranged in a gas atmosphere within the housing. This can particularly mean that the at least one movable contact is completely located in the gas atmosphere within the housing and that, furthermore, at least parts of the stationary contact(s), such as the contact area(s) of the stationary contact(s), are also located in the gas atmosphere within the housing. Accordingly, the switching device can particularly preferably be a gas-filled switching device, such as a gas-filled contactor.

[0016] According to a further embodiment, the contacts, meaning the at least one movable contact completely and at least parts of the fixed contact(s), are arranged in a switching chamber within the housing, in which the gas, i.e., at least a part of the gas atmosphere, is located. The gas preferably contains at least 50% H₂. In addition to hydrogen, the gas can contain an inert gas, particularly preferably N₂ and / or one or more noble gases.

[0017] According to a further embodiment, the at least one movable contact is movable by means of a magnetic armature. For this purpose, the magnetic armature can, in particular, have an axle which is connected at one end to the movable contact in such a way that the movable contact can be moved by means of the axle, i.e., is moved by the axle when the axle is moved. The axle can, in particular, project into the switching chamber through an opening in the switching chamber. The magnetic armature can be moved by a magnetic circuit to effect the switching operations described above. For this purpose, the magnetic circuit can have a yoke with an opening through which the axle of the magnetic armature projects. The axle can preferably be made of or consisting of stainless steel. The yoke can preferably be made of or consisting of pure iron or a low-doped iron alloy.

[0018] According to a further embodiment, each of the contacts of the switching device has a contact side on which at least one contact area is arranged. The contact area of ​​each contact can, in particular, be that part of a surface on the contact side of the respective contact which, during normal operation of the switching device, is designed and configured to make mechanical contact with another contact when the switching device is switched on. The surface with the contact area is here and in the following also referred to as the contact area, whereby not every part of the contact area needs to be configured as a contact area.

[0019] In particular, the movable contact can have a contact surface that is elongated, especially in the form of a rectangle or approximately a rectangle, for example, a rectangle with chamfered or rounded corners. A portion of the surface on the contact side, i.e., a portion of the contact surface, can form the contact area. If the movable contact is designed and configured to contact at least two stationary contacts, the contact surface has at least two contact areas, which may be separated by one or more surface areas that do not form contact areas. The at least one stationary contact can have a contact surface that, for example, has a round shape, such as a circular shape, or is approximately round, and which forms at least part or preferably all of the contact area.For example, the contact area of ​​a stationary contact can make up at least 70%, or at least 80%, or at least 90% of the contact surface.

[0020] In particular, the contact side of the at least one movable contact can face the at least one stationary contact, and vice versa. The contact side of a contact, and in particular the contact surface, can preferably have a principal plane of extension along which the contact surface extends. Directions parallel to the contact side, and thus to the principal plane of extension of the contact side, can here and in the following be referred to as lateral directions. A direction perpendicular to the contact side, and thus to the principal plane of extension of the contact side, can here and in the following be referred to as a vertical direction. The contacts can be surrounded and bounded in the lateral direction by one or more external surfaces.

[0021] For example, a contact area can be a flat contact surface. Furthermore, the contact area can also have a special geometric shape, such as a raised or recessed area, and / or be made of a different material compared to other areas of the contact.

[0022] According to a further embodiment, at least one contact of the switching device has at least one recess on the contact side. This means that the contact surface does not extend to an outer surface that limits the contact laterally, but is separated from the outer surface, for example, by a step or chamfer. The at least one contact with the at least one recess is at least the movable contact. Additionally, a stationary contact can also have at least one recess. A contact area of ​​a contact surface can directly adjoin a recess in one or more directions.

[0023] For example, the rebate can be formed by a groove or chamfer running along an imaginary edge that would be formed by the contact surface and an outer surface, but which is no longer present due to the groove or chamfer. The rebate can create two outer edges: a first outer edge adjacent to the contact surface and a second outer edge adjacent to the outer surface. The first and second outer edges can be connected by one or more rebate surfaces.

[0024] The height of the setback, i.e., the vertical distance between the first and second outer edges, is denoted by H. The width of the setback, i.e., the lateral distance between the first and second outer edges, is denoted by B. The total thickness of the contact in the vertical direction is denoted by D.

[0025] The recess can, for example, have a rabbet, a chamfer, a concave fillet, or a combination thereof, or be formed by these. The chamfer can be an external chamfer or an internal chamfer.

[0026] For example, the recess can be formed by an external chamfer, i.e., by a chamfer in the area of ​​an outer edge that no longer exists between the contact surface and the outer surface due to the chamfer. In this case, the first and second outer edges are connected by a flat recess surface inclined to the contact surface and the outer surface, which can form an angle of greater than or equal to 10° and less than or equal to 80°, and particularly preferably 45°, with the main extension plane of the contact side, i.e., with the contact surface. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0027] Furthermore, the recess can be formed by a fillet, i.e., a groove with a circular cross-section in the area where the outer edge between the contact surface and the outer surface is no longer present due to the groove. In this case, the first and second outer edges are connected by a curved recess surface, preferably with a cross-section corresponding to a circular segment. The fillet can have a radius R, where the ratio R / D is preferably greater than or equal to 0.05 and less than or equal to 2. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 10 or less than or equal to 5, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0028] Furthermore, the rebound can be formed by a step, such that a first rebound surface adjoins the contact surface, forming the first outer edge with the contact surface at a first angle, while a second rebound surface adjoins the outer surface, forming a second outer edge with the outer surface at a second angle. The first and second rebound surfaces can enclose a third angle. The first, second, and third angles can be the same or different from each other and can each be greater than or equal to 90° and less than 180°, and preferably each be 90°. Particularly preferably, the first rebound surface can be at least partially or completely parallel to the outer surface. Furthermore, the second rebound surface can be at least partially or completely parallel to the contact surface.If the first and second angles are each 90°, dimension H can correspond to the height difference in the vertical direction between the second rebound surface and the contact surface, and dimension B can correspond to the distance between the outer surface and the first side surface.

[0029] For example, the recess can have a fold or be formed by a fold. In this case, the transition between the first and second recess surfaces can be formed by an inner edge, with the third angle preferably being 90°. The first and second angles can also preferably each be 90°. The B / H ratio is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1. Furthermore, the H / D ratio is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0030] Furthermore, the rebate can have an internal chamfer. In this case, the rebate can be formed by a combination of a fold and a chamfer. Compared to a fold with an internal edge between the first and second rebate surfaces, the transition between the first and second rebate surfaces is not formed by an internal edge but by a chamfer in the form of the internal chamfer, so that a third rebate surface is formed between the first and second rebate surfaces. In this case, the first and second rebate surfaces are connected to each other by a flat rebate surface inclined to the first and second rebate surfaces, which can form an angle of greater than or equal to 10° and less than or equal to 80°, and particularly preferably 45°, with the main extension plane of the contact side, i.e., with the contact surface.The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0031] Furthermore, the rebate can be formed by a combination of a fold and a fillet. In other words, the transition from the first to the second rebate surface can be formed by a curved rebate surface, preferably with a cross-section corresponding to a circular segment. The fillet can have a radius R, wherein the ratio R / D is preferably greater than or equal to 0.05 and less than or equal to 2. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 10, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0032] According to a further embodiment, at least one contact of the switching device has a plurality of recesses in different areas, particularly in different lateral directions, on the contact side. The recesses can be separate from one another or merge into one another. Furthermore, different or identical recesses can be present on different lateral sides and thus on different outer surfaces of the contact. Therefore, it is possible for different recess shapes to be formed on different sides. Furthermore, different contacts can also have different recesses.

[0033] According to a further embodiment, the contact surface of a stationary contact projects beyond the contact surface of the movable contact in a lateral direction and / or is coincident with at least a part of it. For example, the contact surface of a stationary contact has a first width and a contact surface of the movable contact has a second width, wherein the first and second widths are measured along the same lateral direction and the first width is equal to or preferably greater than the second width.If the switching device has two fixed contacts that can be electrically connected to each other by a movable contact, the lateral direction along which the first and second widths are measured is preferably perpendicular to a line connecting the centers of the contact surfaces of the two fixed contacts, in which case the first width of each of the fixed contacts is equal to or preferably greater than the second width. Particularly preferably, the contact surface of each of the fixed contacts also projects beyond the contact surface of the movable contact in a lateral direction parallel to a line connecting the centers of the contact surfaces of the two fixed contacts.

[0034] In particular, in one or more areas where the contact surface of a fixed contact extends beyond the contact surface of the movable contact, one or more recesses may be formed on the contact side of the movable contact.

[0035] In the switching device described here, so-called sacrificial areas can be provided by a fixed contact projecting laterally beyond a movable contact and / or by one or more recesses on the contact side of one or more contacts. An arc occurring on a contact surface can easily jump to a sacrificial area, whereby damage caused by arcs in the sacrificial areas advantageously does not lead to a deterioration of the contact resistance between the contact areas. This can be achieved by allowing arcs to travel along and down the described features in the edges of the contacts, thus preventing them from burning on the contact surfaces for extended periods.

[0036] Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described below in conjunction with the figures. Fig. Figure 1 shows a schematic representation of an example of a switching device according to an embodiment, Fig. Figure 2 shows a schematic representation of part of a switching device according to a further embodiment, Fig. 3A and Fig. Figure 3B shows schematic representations of parts of a switching device according to further embodiments, Fig. 4A and Fig. 4B shows schematic representations of parts of a switching device according to further embodiments and Fig. Figures 5A to 6G show schematic representations of parts of a switching device according to further embodiments.

[0037] In the exemplary embodiments and figures, identical, similar, or similarly functioning elements may be designated with the same reference numerals. The depicted elements and their relative sizes are not to be considered to scale; rather, individual elements, such as layers, components, building elements, and areas, may be exaggerated for clarity and / or better understanding.

[0038] In Fig. Figure 1 shows an embodiment of a switching device 100, which can be used, for example, for switching high electrical currents and / or high electrical voltages and which can be a relay or contactor, in particular a power contactor. Fig. Figure 1 shows a three-dimensional sectional view with a vertical cutting plane. The geometries shown are only examples and not to be understood as limiting; alternative configurations are also possible.

[0039] The switching device 100 has contacts 1, hereinafter also referred to as switching contacts, within a housing (not shown). The housing primarily serves as contact protection for the components arranged inside and is made of or comprised of a plastic material, for example, PBT or glass fiber-reinforced PBT. In the illustrated embodiment, the switching device 100 has two fixed contacts 2 and one movable contact 4 mounted on an insulator 3. The movable contact 4 is designed as a contact plate. The fixed contacts 2, together with the movable contact 4, form the switching contacts. Alternatively, other numbers of contacts 1, i.e., other numbers of fixed and / or movable contacts, are possible.The fixed contacts 2 and / or the movable contact 4 can be made of or with Cu, a Cu alloy, one or more high-melting-point metals such as Wo, Ni and / or Cr, or a mixture of the aforementioned materials, for example copper with at least one other metal, for example Wo, Ni and / or Cr.

[0040] In Fig. Figure 1 shows the switching device 100 in a switched-off state, in which the movable contact 4 is spaced apart from the stationary contacts 2, so that contacts 2 and 4 are galvanically isolated from each other. The illustrated design of the switching contacts, and in particular their geometry, are purely exemplary and not to be understood as limiting. Alternatively, the switching contacts can also be designed differently.

[0041] The switching device 100 has a movable magnetic armature 5, which essentially performs the switching movement. The magnetic armature 5 has a magnetic core 6, for example, made of or with a ferromagnetic material. Furthermore, the magnetic armature 5 has a shaft 7, which is guided through the magnetic core 6 and is fixedly connected to the magnetic core 6 at one end. At the other end of the shaft, opposite the magnetic core 6, the magnetic armature 5 has the movable contact 4, which is also connected to the shaft 7. The shaft 7 can preferably be made of or with stainless steel.

[0042] To electrically isolate the movable contact 4 from the axis 7, the insulator 3, which can also be called a bridge insulator, is positioned between them. To mount the movable contact 4 onto the insulator 3, the insulator can be inserted into an opening in the movable contact 4 in a position rotated about the axis 7. The opening in the movable contact 4 and the shape of the insulator 3 are designed such that when the movable contact 4 is rotated relative to the insulator 3 into the correct installation position, it locks upwards onto the insulator 3, preventing it from slipping off. For example, locking lugs on the insulator 3 and corresponding grooves in the opening of the movable contact 4 can be provided for this purpose.Simultaneously, the opening in the movable contact 4 can be large enough that, in its installed state, the movable contact 4 can still be slightly tilted towards the axis 7 and moved along the axis 7, thus compensating for any existing height differences. To assist in compensating for potential height differences and to ensure sufficient mechanical contact between the fixed contacts 2 and the contact bridge 4, a contact spring 34 is arranged below the movable contact 4. This spring is supported by the insulator 3 and exerts a force on the movable contact 4 in the direction of the fixed contacts 2.

[0043] The magnetic core 6 is surrounded by a coil 8. A current flow in the coil 8, which can be switched on externally by a control circuit, causes the magnetic core 6, and thus the entire magnetic armature 5, to move in the axial direction until the movable contact 4 makes contact with the stationary contacts 2. In the illustration, the magnetic armature moves upwards. The magnetic armature 5 thus moves from a first position, a rest position corresponding to the disconnecting (i.e., non-conducting and therefore off) state, to a second position corresponding to the active (i.e., conducting and therefore switched on) state. In the active state, the contacts 1 are galvanically connected to each other.

[0044] To guide the axis 7 and thus the magnetic armature 5, the switching device 100 has a yoke 9, which may be made of or consist of pure iron or a low-doped iron alloy and which forms part of the magnetic circuit.

[0045] The yoke 9 has an opening in which the shaft 7 is guided. If the current flow in the coil 8 is interrupted, the magnetic armature 5 is moved back to its initial position by one or more springs 10. In the illustration shown, the magnetic armature 5 thus moves downwards again. The switching device 100 is then back in its rest state, in which the contacts 1 are open.

[0046] The direction of movement of the magnetic armature 5, and thus of the movable contact 4, is hereinafter also referred to as the vertical direction 91. The arrangement direction of the fixed contacts 2, which is perpendicular to the vertical direction 91, is hereinafter referred to as the longitudinal direction 92. The direction perpendicular to both the vertical direction 91 and the longitudinal direction 92 is hereinafter referred to as the transverse direction 93. The directions 91, 92, and 93, which also apply independently of the described switching movement, are indicated in some figures for ease of orientation. Directions that are parallel to a plane spanned by the longitudinal direction 92 and the transverse direction 93, and thus perpendicular to the vertical direction 91, are also referred to as the lateral directions 90.

[0047] For example, when contacts 1 are opened, at least one arc can occur, which can damage the contact surfaces of contacts 1. This can lead to the risk that contacts 1 will "stick" together due to arc welding and can no longer be separated. The switching device 100 would then remain in the switched-on state, even though the current in coil 8 is switched off and the load circuit should therefore be disconnected. To prevent the formation of such arcs, or at least to aid the extinguishing of any arcs that do occur, contacts 1 can be located in a gas atmosphere, so that the switching device 100 can be designed as a gas-filled relay or gas-filled contactor.For this purpose, the contacts 1 are arranged within a switching chamber 11, formed by a switching chamber wall 12 and a switching chamber base 13, in a gas-tight region 14 formed by a hermetically sealed part, wherein the switching chamber 11 can be part of the gas-tight region 14. The gas-tight region 14 completely surrounds the magnetic armature 5 and the contacts 1, except for parts of the fixed contacts 2 intended for external connection. The gas-tight region 14, and thus also the interior 15 of the switching chamber 11, is filled with a gas. The gas-tight region 14 is essentially formed by parts of the switching chamber 11, the yoke 9, and additional walls.The gas that can be filled into the gas-tight area 14 through a gas filling nozzle during the manufacture of the switching device 100 can particularly preferably contain hydrogen, for example with 20% or more H2 in an inert gas or even with 100% H2, since hydrogen-containing gas can promote the quenching of electric arcs.

[0048] The switching chamber wall 12 and the switching chamber base 13 can, for example, be made with or from a metal oxide such as Al2O3. Furthermore, plastics with sufficiently high temperature resistance are also suitable, for example, PEEK, PE, and / or glass fiber-reinforced PBT. Alternatively or additionally, the switching chamber 11 can also be made at least partially of POM, in particular with the structure (CH2O) n, exhibit. Such a plastic can be characterized by a comparatively low carbon content and a very low tendency to form graphite. Due to the equal proportions of carbon and oxygen, especially in (CH2O) n During heat-induced decomposition, and especially arc-induced decomposition, predominantly gaseous CO and H2 are produced. The additional hydrogen can intensify arc quenching.

[0049] The features of the switching device 100 described above are purely exemplary and not to be understood as limiting. For example, the switching device 100 can alternatively be designed as a gas-filled contactor as described above, or it can be designed without gas filling. For example, due to the design of the contacts 1 described below, it may be possible, as also described in the general section, for so-called sacrificial areas to be formed on one or more contacts 1, where arcs can propagate away from the contact surfaces, thus reducing, among other things, the tendency for arc-induced welding of contacts. Therefore, it is also possible for the switching device 100 to be designed without a gas-tight area.

[0050] As in Fig. As can be seen in Figure 1, each of the contacts 1 has a contact side 20, 40, wherein the contact side 20 of each of the fixed contacts 2 faces the movable contact 4 and the contact side 40 of the movable contact 4 faces each of the fixed contacts 2. Fig. Figure 2 shows a fixed contact 2 and a movable contact 4 in a section. The respective surfaces on contact sides 20, 40 form the contact surfaces 21, 41 of the fixed and movable contacts 2, 4. The contact surfaces 21, 41 each have contact areas 22, 42. The contact area 22, 42 of each of the contacts 1 can, in particular, be that part of the respective contact surface 21, 41 which, during normal operation of the switching device 100, is designed and configured to make mechanical contact with another contact when the switching device 100 is switched on. Not every area of ​​a contact surface needs to be configured as a contact area.Furthermore, the contact surface of a contact can also have more than one contact area, as is the case with the movable contact 4 in the switching device 100 shown, which has a corresponding contact area 42 on the contact surface 41 for each of the fixed contacts 2. These contact areas are separated from each other by an area of ​​the contact surface 41 that is not intended as a contact area. As also shown in... Fig. As can be seen from 1, the movable contact 4 may, for example, have a contact surface 41 which has an elongated shape with a main extension direction in the longitudinal direction 92, in particular in the form of a rectangle or approximating the shape of a rectangle, such as a rectangle with beveled or rounded corners.

[0051] In the illustrated embodiment, the contact surface 21 of each of the stationary contacts 2 forms the respective contact area 22 completely or at least substantially completely. For example, the contact area 22 of a stationary contact can comprise at least 70%, at least 80%, or at least 90% of the contact surface 21. The contact surface 21, and thus the contact area 22 of the stationary contacts 2, can preferably have a round shape, such as a circular shape, or be approximately round. Similarly, the contact areas 42 of the movable contact 4 can have a round shape or be approximately round.

[0052] For example, a contact area 22, 42 of a contact 1 can be a flat bearing surface of the contact surface 21, 41. Alternatively, the contact area 22, 42 can also have a special geometric shape, such as a raised or recessed area, and / or be made of a different material compared to other areas of the contact.

[0053] In the lateral directions 90, for example in the Fig. In the 2 recognizable longitudinal direction 92, the contacts 1 are bounded by outer surfaces 23, 43. The distances between the outer surfaces 23, 43 opposite each other in a lateral direction 90 can particularly preferably define the maximum extent of a contact along this lateral direction 90.

[0054] Preferably, the entire contact surfaces 21 of the stationary contacts 2 are congruent with a part of the contact surface 41 of the movable contact 4 or project beyond the contact surface 41 and thus the contact areas 42 of the movable contact 4 in several lateral directions 90, as shown in the Fig. 3A and Fig. 3B is indicated in sections of the switching device. For example, the contact surface 21 of each of the fixed contacts 2 has a first width T2 and the contact surface 41 of the movable contact 4 has a second width T4, wherein the first and second widths T2, T4 are measured along the same lateral direction 90. In the illustrated embodiment of the Fig. 3A, the widths T2 and T4 are the widths of the contact surfaces 21, 41 in the transverse direction 93. The first width T2 of the contact surface 21 of each of the fixed contact 2 is equal to or preferably as shown in Fig. 3A is shown, larger than the second width T4 of the contact surface 41 of the movable contact 4.

[0055] Furthermore, the respective contact surface 21 of the fixed contacts 2 preferably also projects beyond the contact surface 41 of the movable contact 4 in the longitudinal direction 92, as in the exemplary embodiment of the Fig. 3B is to be granted. Here, as also in Fig. As can be seen in Figure 3B, the outer surfaces 23, 43 of the contacts 1 are congruent in at least one lateral direction 90. This can also be the case in the transverse direction 93. Furthermore, for example, as shown in Fig. As can be seen in the transverse direction 93, the outer surfaces 43 of the movable contact 4 project beyond the outer surfaces 23 of the fixed contacts 2 in the lateral direction 90. Alternatively, a reverse configuration is also possible.

[0056] With regard to the previously described configurations of the contacts 1 relative to each other, it can be particularly advantageous if at least one contact 1 of the switching device has at least one recess 50 on the contact side 20, 40. This means that the contact surface 21, 41 does not extend to an outer surface 23, 43 that laterally delimits the contact 1, but is separated from the outer surface 23, 43, for example, by a step or chamfer. The at least one contact 1 with the at least one recess 50 can preferably be a movable contact 4, as in the exemplary embodiment of Fig. 4A is shown. A recess 50 can be formed on an outer surface 43, on two outer surfaces 43 opposite each other in a lateral direction 90, or, at least in the area of ​​the contact areas, on all outer surfaces 43, as shown in Fig. 4A is recognizable. The one in Fig. The movable contact 4 shown in 4A thus has for each of the contact areas 42 indicated by the dashed lines a special edge shape formed by the recess on all three possible deflection sides for arcs.

[0057] Alternatively or additionally, the fixed contacts 2 can also have at least one return step 50, as in the embodiment shown in the Fig. 4B is shown. In the case of the fixed contacts 2, the rebate 50 can preferably be formed in all lateral directions 90 on the outer surfaces 23.

[0058] As in the Fig. 4A and Fig. As can be seen in 4B, a recess 50 can be formed by a groove or chamfer running along an imaginary edge that would be present between the contact surface and an outer surface without the groove or chamfer and which is no longer present due to the groove or chamfer, between the contact surface 21, 41 and the outer surface 23, 43.

[0059] In the Fig. 5A to 5C as well as in Fig. Sections 6A to 6G are shown purely as examples of movable contact 4, including sections of contact 1 with a recess 50 on the outer surface 43 that limits the longitudinal dimension 92. Fig. Figures 6A to 6G show various configurations for the rebate. The following description of different rebate configurations expressly applies equally to fixed contacts. Furthermore, identical or different rebate configurations are possible on different sides, i.e., in different lateral directions. For example, in the case of movable contact 4, a first rebate configuration can be provided on the outer surfaces in the transverse direction, while a second rebate configuration, different from the first, can be provided on the outer surfaces in the longitudinal direction.

[0060] As in the Fig. As shown in Figures 5A to 5C, the recess 50 forms two outer edges 51, 52, of which a first outer edge 51 adjoins the contact surface 41 and a second outer edge 52 adjoins the outer surface 43. The first and second outer edges 51, 52 can be connected to each other via one or more recess surfaces 53, 54. Fig. Dimensions H and B for the return step 50 and the thickness D of contact 1 are indicated in 5B. The in Fig. The dimensions H and B indicated in Figure 5B apply to all subsequent embodiments of the recess 50, as they refer to the always present outer edges 51 and 52, regardless of the shape of the recess 50. Even if the outer edges 51 and 52 are indicated as sharp edges, they can also be rounded or chamfered, in which case the dimensions given below apply accordingly.

[0061] The height of the setback 50, i.e., the distance in the vertical direction 91 between the first outer edge 51 and the second outer edge 52, is hereby designated H. The width of the setback 50, i.e., the distance in the lateral direction 90 between the first outer edge 51 and the second outer edge 52, is hereby designated B. The total thickness of the contact in the vertical direction 91 is hereby designated D.

[0062] As in Fig. As indicated in 5C, the contact surface 41 forms a first angle α1 with the adjacent first rebound surface 53 at the first outer edge 51, while the outer surface 43 forms a second angle α2 with the adjacent second rebound surface 54 at the second outer edge 52. The first rebound surface 53 and the second rebound surface 54 can form a third angle α3.

[0063] The regression can, for example, be a step, especially, as in the Fig. 5A and Fig. 5B indicates that a fold, chamfer, concave fillet, or a combination thereof may be present or formed by such a feature. The chamfer can be an external or internal chamfer.

[0064] The dimensions and angles described below refer to, unless otherwise stated in the following descriptions. Fig. 6A to 6G shown, which in conjunction with the Fig. Dimensions and angles described in sections 5A to 5C.

[0065] In connection with the Fig. Figures 6A to 6C show inset embodiments of a contact 1 with a rebate 50, wherein the rebate 50 is formed by a step in the form of a fold. The first, second, and third angles α1, α2, α3 can be the same or different from each other and can each be greater than or equal to 90° and less than 180°, preferably each being 90°. Particularly preferably, the first rebate surface 53 can be at least partially or completely parallel to the outer surface 43. Furthermore, the second rebate surface 54 can be at least partially or completely parallel to the contact surface 41. If the first and second angles α1, α2 are each 90°, the distance H can correspond to the height difference in the vertical direction between the second rebate surface 54 and the contact surface 41, while the distance B corresponds to the lateral distance of 90° between the outer surface 43 and the first rebate surface 53.

[0066] In the Fig. In the fold shown in Figures 6A to 6C, the transition between the first and second recessed surfaces 53, 54 is formed by an inner edge 55, wherein the third angle α3 at the inner edge 55 is preferably 90°. The first and second angles α1, α2 can also preferably each be 90° in this case. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5. Fig. Figure 6A shows an example of a fold with B / H = 0.5. For example, B = 0.5 mm and H = 1 mm. Fig. Figure 6B shows an example of a fold with a ratio of W / H = 2. For example, W = 1 mm and H = 0.5 mm. Fig. Figure 6C shows an example of a fold with B / H = 1. For example, B = 1 mm and H = 1 mm.

[0067] As in Fig. As shown in Figure 6D, the setback 50 can have an internal chamfer. In this case, the setback 50 can be formed by a combination of a fold and a chamfer. Compared to a fold with an internal edge 55 between the first and second setback surfaces 53, 54, as shown in the Fig. As shown in Figures 6A to 6C, the transition between the first and second rebound surfaces 53, 54 is not formed by an inner edge but by a chamfer in the form of the inner bevel, so that a third rebound surface 56 is formed between the first and second rebound surfaces 53, 54. In this case, the first and second rebound surfaces 53, 54 are connected to each other by the flat third rebound surface 56, which is inclined to the first and second rebound surfaces 53, 54, forming two inner edges 55. The third rebound surface 56 preferably forms an angle α4 with the main extension plane of the contact surface 41, which is thus the angle of the inner bevel and is greater than or equal to 10° and less than or equal to 80°, and particularly preferably 45°. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1.Furthermore, the H / D ratio is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0068] Furthermore, as in Fig. As shown in Figure 6E, the recess 50 is formed by an external chamfer, i.e., by a bevel in the area of ​​an outer edge that no longer exists due to the chamfer between the contact surface 41 and the outer surface 43. In this case, the first and second outer edges 51, 52 are connected to each other by a flat recess surface 53 inclined to the contact surface 41 and the outer surface 43, which preferably forms an angle α4, i.e., a chamfer angle, with the main extension plane of the contact surface 41 of greater than or equal to 10° and less than or equal to 80°, and particularly preferably of 45°. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 5, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0069] As in Fig. As shown in Figure 6F, the rebate 50 can also be formed by a combination of a fold and a fillet. In other words, the transition from the first to the second rebate surface 53, 54 can be formed by a curved rebate surface 56, preferably with a cross-section corresponding to a circular segment. The fillet can have a radius R, wherein the ratio R / D is preferably greater than or equal to 0.05 and less than or equal to 2. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 10, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0070] Furthermore, as in Fig.As shown in Figure 6G, the recess 50 is formed by a fillet, i.e., by a groove with a circular cross-section in the area of ​​an outer edge that no longer exists due to the groove between the contact surface 41 and the outer surface 43. In this case, the first and second outer edges 51, 52 are connected to each other by a curved recess surface 53, preferably with a cross-section corresponding to a circular segment. The fillet can have a radius R, wherein the ratio R / D is preferably greater than or equal to 0.05 and less than or equal to 2. The ratio B / H is preferably greater than or equal to 0.2 and less than or equal to 10, and particularly preferably 1. Furthermore, the ratio H / D is preferably greater than 0 and less than or equal to 0.8, and particularly preferably greater than or equal to 0.1 and less than or equal to 0.5.

[0071] The recessed surfaces can form so-called sacrificial areas onto which an arc can "jump" from the contact surfaces of a stationary contact and a moving contact. This can be facilitated in particular by ensuring that at least one contact surface projects over an opposing contact surface with a recess in the lateral direction or is at least congruent with it. This allows arcs to be kept away from the contact surfaces, thus reducing the risk of arc-induced damage to the contact surfaces and especially the contact areas, and the associated deterioration of the contact resistance.

[0072] The features and embodiments described in connection with the figures can be combined with one another according to further embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in connection with the figures can alternatively or additionally include further features as described in the general section.

[0073] The invention is not limited to the description provided by means of the exemplary embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the claims, even if that feature or combination itself is not explicitly stated in the claims or exemplary embodiments. Reference symbol list 1 contact 2 fixed contacts 3 Insulator 4 movable contacts 5 magnetic anchors 6 magnetic core 7-axis 8 coil 9 yoke 10 springs 11 Switching chamber 12 Switch chamber wall 13 Switch chamber floor 14 gas-tight area 15 Interior 16 permanent magnet 20, 40 Contact page 21, 41 contact area 22, 42 Contact area 23, 43 outdoor area 34 Contact spring 50 rebound 51, 52 outer edge 53, 54 Rebound area 55 inner edge 56 rebound area 90 lateral direction 91 vertical direction 92 longitudinal direction 93 transverse direction 100 switching device B distance Thickness H distance T2, T4 width α1, α2, α3, α4 angles

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