Switching Device

Abstract

A switching device (100) is presented, comprising at least one fixed contact (1) and one movable contact (2) in a switching chamber (11), a contact element (4) outside the switching chamber, and a mechanical drive with an axis (7), the mechanical drive intended and adapted to move the movable contact and the contact element, and at least two auxiliary contacts are provided outside the switching chamber, on the opposite side of the axis to the movable contact.

Description

[Technical Field]

[0001] A switching device is presented. [Background technology]

[0002] The switching device is particularly designed as a current-driven, electromagnetically actuated, remotely operated switch. The switching device can be operated 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, in particular 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 disconnection of battery circuits, for example in motor vehicles, such as electrically or partly electrically driven motor vehicles, or in applications in the field of renewable energy.

[0004] In their function as safety components, contactors, for example, are usually additionally monitored, and this contactor monitoring is regulated in the standard IEC 60947-5-1. Contactor monitoring is intended to be used, for example, to detect the most frequent fault of contactors, relays, and switches, namely, so-called sticking, i.e., welding of the main contacts. Such a fault, also known as contactor sticking, can be caused, for example, by an arc that forms between the contacts during switching operations under load and can cause the contact surfaces to reach such high temperatures that they are welded together. Furthermore, it would be advantageous if further fault conditions could be detected, for example, when the contacts are mechanically blocked in the open position or an intermediate state.

[0005] Typical contactors are designed as so-called overstroke systems. This means that after the main contacts are interconnected by the switching bridge and therefore electrically closed, the closing system continues to move, increasing the normally spring-loaded pressure of the switching bridge against the main contacts. In the event of a stuck contactor, this overstroke is eliminated again, but the switching bridge remains stuck to at least one main contact. The mechanical system therefore remains in an intermediate state, neither opening nor closing properly.

[0006] Monitoring or contactor sticking detection can be done, for example, by measuring the voltage across the main contacts of the contactor. If there is a voltage across the main contacts, it is inferred that the contactor is open. If there is no voltage, it is inferred that the contactor is shorted and therefore closed. This method is very reliable, but also expensive to use, since wiring that is loaded with high voltage potentials must be laid and properly insulated. Monitoring is usually performed by a high-level system, such as an analog-to-digital converter controlled by a microcontroller.

[0007] For example, it is also known to use a microswitch operated by a small cantilever on the switching bridge in the switching chamber of a contactor. The cantilever operates the switch just before the switching bridge presses against the main contacts. The switch can then be designed as a closure (closes when pressed) or an opener (opens when pressed). The signal of the microswitch can therefore be designed inversely compared to the switching state of the contactor. A drawback of this solution is that the microswitch must be located close to the main contacts inside the switching chamber. This can sometimes affect arc quenching or lead to insulation problems. Furthermore, the monitoring contact formed by the cantilever and microswitch must be pre-formed. This means that the monitoring contact changes state before the main contacts close. This is because the microswitch still displays a "closed" state if the overstroke limit has already been reached during adhesion. Therefore, intermediate states or blockages cannot be detected. A further drawback is the service life of a typical microswitch, which, depending on the design, can only reach several hundred thousand switching cycles. Furthermore, wires must be routed to the switch, which limits the use of a completely hermetically sealed ceramic discharge space.

[0008] Furthermore, for example, from US Pat. No. 5,629,999, auxiliary switches are known that are operated via a cantilever on a switching bridge, in which, for example, two overlapping contacts can be pressed against each other. This solution is certainly simple, inexpensive, and hardly wears out. However, it has the disadvantage that the overlapping contacts are mounted between the main contacts, which can lead to insulation problems. Furthermore, conductors must be laid to the auxiliary switch, which limits or makes impossible the use of a completely hermetically sealed ceramic discharge space. The switching behavior remains similar to that of a microswitch.

[0009] To avoid the above-mentioned drawbacks, it is also known to mount a magnet that can open or close a reed switch underneath the moving system, specifically outside the switching chamber, as described in, for example, US Pat. No. 5,629,499. This allows detection to occur far from the main contacts, even through non-magnetic materials. Furthermore, this solution can be easily used in conjunction with hermetically sealed ceramic discharge spaces. The switching behavior is similar to the two systems described above, but the difficulty arises in correctly adjusting the overlap area, since the indication is magnetic and hysteresis effects must also be taken into account. A further drawback is the susceptibility of reed switches to magnetic interference fields and mechanical shocks.

[0010] A known improvement is to use a Hall sensor instead of a reed switch, so that magnetic detection is performed by semiconductor components rather than by a mechanical switch. Magnetic interference fields no longer play a role, and vibration dependency no longer exists. However, the switching behavior is similar to that of a reed switch.

[0011] All four monitoring switch solutions have the so-called "normally open" characteristic, i.e., the monitoring switch broadly reflects the state of the main contacts. However, signal inversion does not produce a "normally closed" state, only a "not normally open" state. Notably, common to all four principles is that none of these solutions can reliably signal that the monitored contactor is reliably and fully open. However, such a requirement is codified in standard IEC 60947-4-1, which requires that the monitoring contacts be closed only when the contactor is in the idle position, or that the detection of a closed monitoring contact be clearly indicated ("normally closed"). Such a solution is not known so far for gas-filled contactors.

[0012] In Patent Documents 3 and 4, it is proposed to provide an additional intermediate chamber with a monitoring contact, via which the options "normally open" and "normally closed" can be freely selected, between the switching chamber and the area with the switching driver. The disadvantage of this variant is that the intermediate chamber requires more space, which can have a negative impact on the weight, size and cost of the contactor. The arrangement of the monitoring contact in the switching chamber, which is led out of the switching chamber and needs to be protected from arcs, for example by a plastic shield, can also require more space in order to maintain the necessary insulating distance between the high-voltage and low-voltage parts. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. 2008 / 033349 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-008621 [Patent Document 3] European Patent Application Publication No. 2843683 [Patent Document 4] European Patent Application Publication No. 3471127 Summary of the Invention [Problem to be solved by the invention]

[0014] At least one objective of certain embodiments is to provide a switching device. [Means for solving the problem]

[0015] This problem is solved by the subject matter of the independent claims. Advantageous embodiments and developments of the subject matter are set out in the dependent claims and will become apparent further from the following description and drawings.

[0016] According to at least one embodiment, 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 intended and adapted to switch on and off a load circuit connectable to the switching device. Particularly preferably, the switching device has at least two fixed contacts, which, together with the movable contact, are intended and adapted to switch on and off a load circuit connectable to the switching device, in particular to the at least two fixed contacts. In the following, the switching device is generally described as having two fixed contacts. However, the number of fixed contacts may differ from the number specifically mentioned in the following embodiments and in connection with the features described below.

[0017] The movable contact is movable between a disconnected state and a connected state of the switching device such that in the disconnected state of the switching device, the movable contact is separated from and thus electrically isolated from at least one or at least two fixed contacts, and in the connected state, the movable contact is in mechanical contact with and thus electrically connected to at least one or at least two fixed contacts. Thus, in the connected state, the movable contact is in contact with at least one or at least two fixed contacts. In the case of at least two fixed contacts, the fixed contacts are therefore arranged separately from one another in the switching device and can be conductively connected to one another or electrically isolated from one another via the movable contact, depending on the state of the movable contact. In the connected state, the movable contact is in contact with at least one contact surface of each of the fixed contacts. The distance of the movable contact, particularly the aforementioned contact surface of the movable contact, from the fixed contact, particularly the aforementioned contact surface of the fixed contact, in the disconnected and therefore isolated state, is herein and hereinafter also referred to as the switching gap or switching path, and indicates the maximum range of movement of the movable contact, and therefore the maximum reachable distance of the fixed contacts to the movable contact, particularly the distance of their contact surfaces relative to one another.

[0018] According to a further embodiment, the switching device has a switching chamber in which a movable contact and at least one or at least two fixed contacts are arranged. The movable contact may, in particular, be arranged completely within the switching chamber. Arranging the fixed contact within the switching chamber may, in particular, mean that at least the contact area of ​​the fixed contact, which is in mechanical contact with the movable contact in the connected state, is arranged within the switching chamber. For connection of the conductors of the circuit to be switched by the switching device, the fixed contacts arranged within the switching chamber may be electrically accessible from the outside, i.e., from outside the switching chamber. For this purpose, the fixed contacts arranged within the switching chamber may partially protrude from the switching chamber and may have the possibility of connection for the conductors outside the switching chamber. Therefore, the switching chamber preferably has openings through which the fixed contacts protrude into the switching chamber. The fixed contacts are, for example, soldered into the openings of the switching chamber and protrude into the interior space of the switching chamber and out of the switching chamber.

[0019] The switching chamber may in particular have an internal space surrounded by a switching chamber wall. For this purpose, the switching chamber may have, for example, a switching chamber cover and a switching chamber bottom, which may preferably completely surround the internal space. This includes cases where the switching chamber cover and / or the switching chamber bottom have openings through which elements such as, for example, fixed contacts protrude into the switching chamber and thus into the internal space.

[0020] According to a further embodiment, the switching device has at least two auxiliary contacts arranged outside the switching chamber, which may in particular mean that the auxiliary contacts are arranged outside the interior space of the switching chamber and therefore do not protrude into the switching chamber.

[0021] According to a further embodiment, the switching device has at least one contact element arranged outside the switching chamber, in other words the contact element, such as an auxiliary contact, is arranged outside the interior space of the switching chamber.

[0022] According to a further embodiment, the contact element is movable together with the movable contact. Particularly preferably, the contact element and the movable contact can be moved together by the same mechanical drive, which is further described below. Preferably, the at least two auxiliary contacts are arranged outside the switching chamber on the opposite side of the mechanical drive from the movable contact.

[0023] According to a further embodiment, the contact element contacts at least two auxiliary contacts in the first switching state of the switching device. In other words, the contact element is in mechanical and therefore electrical contact with the at least two auxiliary contacts in the first switching state. The at least two auxiliary contacts are preferably electrically connected to each other and thus short-circuited by the contact element. Furthermore, the contact element can be separated from the auxiliary contacts in the second switching state. The first switching state can particularly preferably be the aforementioned disconnected switching state of the switching device, while the second switching state can be the aforementioned connected state. In other words, the contact element can contact the auxiliary contacts when the movable contact is separated from at least one fixed contact, while the contact element is separated from at least two auxiliary contacts when the movable contact of the switching device is in contact with at least one fixed contact. In other words, in this case, if electrical contact is detected between the auxiliary contacts, this means that the switching device is in the disconnected state. That is, in this case, the auxiliary contact and the monitoring contact so formed by the contact element have the above-mentioned "normally closed" characteristic.

[0024] Alternatively, the first switching state can be a connected switching state, while the second switching state is a disconnected state. In this case, the operating principle of detecting the state of the switching device via the auxiliary contacts is reversed in the following description and corresponds to a "normally open" implementation. Furthermore, the contact element can be arranged separated from the auxiliary contacts in the first switching state of the switching device, which is the disconnected state of the switching device, and the contact element contacts the auxiliary contacts in the second switching state of the switching device, which is the connected state of the switching device. Thus, in this configuration, the contact element then contacts at least two auxiliary contacts in the second switching state of the switching device. In other words, the contact element is in mechanical and therefore electrical contact with the at least two auxiliary contacts in the second switching state. Thus, in this configuration, the contact element can be separated from at least two auxiliary contacts when the movable contact is separated from at least one fixed contact, while the contact element can be in contact with the auxiliary contacts when the movable contact of the switching device is in contact with at least one fixed contact. That is, when electrical contact is detected between the auxiliary contacts, this means that in this configuration the switching device is in a connected state. The monitoring contact formed by the auxiliary contact and the contact element reflects the state of the switching contacts and has a "normally open" characteristic.

[0025] According to a further embodiment, the switching device has a housing in which the movable contact, the fixed contact, and the auxiliary contact and contact element are arranged. Furthermore, the switching chamber is located inside the housing. Arranging the fixed contact inside the housing may particularly mean that at least one contact area of ​​the fixed contact, which is in mechanical contact with the movable contact in the connected state, is arranged inside the housing. For connection of the conductors of the circuit to be switched by the switching device, the fixed contacts arranged inside the housing may be electrically contactable from the outside, i.e., from outside the housing. For this purpose, parts of the fixed contacts arranged inside the housing may protrude from the housing and have the possibility of connection for conductors outside the housing. This may particularly apply to each fixed switching contact. The movable contact may, in particular, be arranged completely inside the housing. Furthermore, preferably, the auxiliary contacts may also be arranged completely inside the housing. The auxiliary contacts may be externally contactable, for example, via conductors inside the housing that are conductively connected to external electrical connections on the housing. Alternatively, there may be electrical components within the housing, such as a microcontroller or other electrical parts for contacting and / or reading the auxiliary contacts, which are connected to the auxiliary contacts via power supply lines, again which may be externally accessible via suitable connections on the housing.

[0026] According to a further embodiment, the contacts are arranged in a gas atmosphere in the housing. The gas atmosphere may in particular be enclosed in a gas-tight region of the switching device. The movable contact and the contact element may each be completely arranged in the gas atmosphere in the housing, but parts of the fixed contacts, such as the contact areas of the fixed contacts, and parts of the auxiliary contacts, such as the contact areas of the auxiliary contacts, may be arranged in the gas atmosphere in the housing. Correspondingly, at least two auxiliary contacts are arranged partly in the gas-tight region and partly outside the gas-tight region.

[0027] A portion of the gas atmosphere may be located inside the switching chamber. Another portion of the gas atmosphere may be located outside the switching chamber. Thus, the switching chamber may be part of a gas-tight region, i.e., a region completely filled with gas. Accordingly, the switching device may particularly preferably be a gas-filled switching device, such as a gas-filled contactor. The gas-tight region preferably has a wall that may be composed of multiple parts and may have wall regions made of different materials. For example, a portion of the switching chamber, such as a switching chamber cover, may form part of the wall of the gas-tight region. In this case, the switching chamber cover may particularly preferably be made of a gas-tight material, such as a ceramic material. Furthermore, the wall of the gas-tight region may have a wall region that includes or consists of stainless steel, for example. Such a wall region that includes or consists of stainless steel may be hermetically soldered or welded to the switching chamber cover, for example.

[0028] Furthermore, at least two auxiliary contacts may be arranged within the ceramic element and protrude through it. For this purpose, the ceramic element has openings, each of which has an auxiliary contact arranged therein, and the auxiliary contacts are particularly preferably hard-soldered to the edges of the openings. For this purpose, each auxiliary contact may have a flange with a fixing region, by which the auxiliary contact is soldered to the edge region of the opening around the periphery of the ceramic element. Here and below, solders with a melting point of 600°C or higher are referred to as hard solders. Examples of hard solders that can be used include silver- and / or copper-based solders, such as silver-copper alloys like Ag72Cu28. The ceramic element may form part of the wall of the hermetic region and may be connected to a wall region that includes or consists of stainless steel or other non- or weakly magnetic alloys. Such a wall region that includes or consists of stainless steel may be hermetically soldered or welded to the ceramic element, for example. The ceramic element and the wall region connected to it may together form a cup shape. In particular, the ceramic element can form a cup-shaped bottom, while the wall area connected to the ceramic element has at least one cylindrical portion forming a side wall of the cup, within which the magnetic core in particular can be guided.

[0029] The gas atmosphere may in particular facilitate the extinguishing of arcs that may occur during the switching operation. The gas of the gas atmosphere may, for example, comprise or be a hydrogen- and / or nitrogen-containing gas, in particular under high pressure. Preferably, the gas may comprise at least 50% H2. In addition to hydrogen, the gas may comprise an inert gas, particularly preferably N2 and / or one or more noble gases.

[0030] According to a further embodiment, the movable contact and the contact element can be moved by a mechanical drive. This can particularly mean that the contact element is arranged on an element of the mechanical drive that causes the switching movement of the movable contact. The mechanical drive can be, for example, a lift drive or a rotary drive. The switching movement of the movable contact from the first switching state to the second switching state and vice versa can therefore be a linear or rotary movement. Correspondingly, the contact element can also perform such a movement during the transition from the first switching state to the second switching state and vice versa.

[0031] The mechanical drive device may particularly have a shaft. The auxiliary contact may particularly preferably be arranged on the shaft opposite the movable contact. In other words, the shaft may have a first end on which the movable contact is arranged, particularly preferably directly or indirectly attached, and a second end on which the auxiliary contact is arranged. Accordingly, a contact element may be directly or indirectly attached to the second end of the shaft. Accordingly, the contact element and the movable contact may be arranged at both ends of the shaft. The shaft may particularly protrude into the switching chamber through an opening in the switching chamber. For example, the switching chamber may have a switching chamber bottom with an opening through which the shaft protrudes.

[0032] For example, the mechanical drive can be designed as a rotary drive and have a stepper motor, which can incrementally rotate the mechanical drive through a predetermined angle around an axis of rotation, preferably defined by a shaft. The shaft can be, for example, part of the motor. Furthermore, the drive unit can have a magnetic drive with a rotatable magnetic armature, which can be rotated by a magnetic circuit to perform the above-mentioned switching operations. For this purpose, the magnetic circuit can have a yoke. The rotatable magnetic armature can have, in particular, a shaft. Furthermore, the magnetic armature can have a magnetic core, which can be attached to the end of the shaft opposite the movable contact and is part of the magnetic circuit, designed as a magnetic rotating core. A magnetic field can be generated in the magnetic circuit by a coil, which can be connected to a control circuit, which rotates the magnetic armature.

[0033] Furthermore, the mechanical drive can be designed as a lift drive, which can cause a linear lift movement, in particular along an axis. In this case, the mechanical drive particularly preferably has a magnetic armature that can be moved linearly by a magnetic circuit to cause the above-mentioned switching process. For this purpose, the magnetic circuit can have a yoke with an opening through which the axis of the magnetic armature protrudes. When the magnetic circuit is switched on, the magnetic armature, in particular the magnetic core of the magnetic armature, can be attracted towards the yoke. In particular, the magnetic core can be fixed to the end of the axis opposite the movable contact and can be part of the magnetic circuit.

[0034] According to a further embodiment, the auxiliary contact and / or the contact element comprises a material containing copper or a copper alloy. Particularly preferably, the material has good electrical conductivity and poor welding tendency. Particularly preferably, the material may be selected from CuBe, CuSn4, CuSn6. Furthermore, for example, the auxiliary contact may comprise the same material as the fixed contact and / or the movable contact.

[0035] According to a further embodiment, the contact element is at least partially spring-shaped, in other words, the contact element has spring-like and therefore elastic properties. Particularly preferably, the contact element or at least part of it is formed by a spring sheet, i.e. an at least partially plate- and / or band-shaped sheet, which can be bent by the application of a force and can return to its original shape in the absence of this force.

[0036] Particularly preferably, the contact element is formed integrally, i.e., at least partially, for example, in the form of a metal band or metal strip, particularly preferably at least partially or entirely in the form of a spring sheet strip. In particular, the contact element may have a contact web or contact ring, at least two connecting webs extending away from the contact web or contact ring, and a contact plate in contact with each of the connecting webs. The contact plates are preferably designed and adapted to be able to mechanically contact the auxiliary contacts. Particularly preferably, the connecting webs may extend away from the contact web or contact ring at an angle of substantially 90°. In the case of contact webs, the connecting webs may, for example, have the same width as the contact webs.

[0037] The connecting webs, the contact plates and the contact webs or the contact rings can preferably be formed by a single metal part. The single metal part has the contact webs, the connecting webs and the contact plates as interconnected parts and can be formed, for example, as a metal strip with a uniform width that can be bent into a rectangular U-shape. Alternatively, the single metal part can have a contact ring with at least two strips arising from the contact ring, which are bent away from the main extension plane of the contact ring and which preferably enclose an angle of 90° or at least substantially 90° with the main extension plane of the contact ring.

[0038] Each connecting web can have a contact plate at its end opposite the contact web or contact ring, which can be inclined relative to the connecting web and can subtend an angle with the connecting web of, for example, 90° or more, or 100° or more, and 160° or less, or 140° or less, or 135° or less. The contact plate can have a width equal to or greater than the width of the connecting web. For example, the contact plate can be formed semicircular. In particular, the contact plates can face each other.

[0039] Furthermore, the contact plates may have a distance from one another that is smaller than the width of the auxiliary contacts, in which case the width of the auxiliary contacts refers in particular to the width of the contact surface of the auxiliary contacts and may be measured in the direction along which the distance between the contact plates is measured. The contact plates may therefore preferably cover as large an area as possible, for example a substantially circular area, excluding gaps having a width corresponding to the aforementioned distance.

[0040] Furthermore, the contact element has a plurality of connecting webs separated by slits and arranged circumferentially on the contact ring, with a contact plate arranged on each of the connecting webs. The connecting webs can be arranged on the outer edge of the contact ring or on the inner edge of the contact ring.

[0041] The contact elements can be fixed, for example, directly to the shaft. If the mechanical drive has a magnetic core as described above, the contact elements can be particularly preferably fixed to the magnetic core. In this case, it is particularly preferred that the contact elements are directly fixed to the magnetic core. In particular, a contact web or a contact ring can be fixed to the magnetic core. Preferably, the contact elements, i.e., particularly preferably the contact web or the contact ring, can be welded to the magnetic core. The magnetic core can have a recess in which part of the contact element, in particular the contact web or the contact ring, is arranged. The connecting web can protrude from the recess.

[0042] If the mechanical drive is designed as a magnetic drive, the contact element can be surrounded by the coil of the magnetic drive. Furthermore, at least two auxiliary contacts can also be surrounded by this coil. In other words, the coil can be arranged, for example, around a cylindrical through-opening in which the contact element and / or at least two auxiliary contacts are arranged.

[0043] In the case of a mechanical drive designed as a lift drive, this can have a return spring that causes or at least assists the movement of the magnet armature back from the second switching position to the first switching position when the electromagnet is switched off. The return spring can have a return spring force RFK, and the contact element can have a spring force FK with FK < RFK, so that the spring force of the contact element is less than the force exerted by the return spring on the magnet armature. Particularly preferably, FK / RFK ≤ 0.2 holds, so that the switching movement is not restricted by the contact element. The return spring and the contact element can exert forces on the magnet armature in the same or opposite directions, and in either case, preferably FK / RFK ≤ 0.2 holds.

[0044] Furthermore, in order to close the switching gap, the movable contact can move along the switching path SW during the transition from the first switching state to the second switching state. The mechanical drive, and thus the magnet armature, can close the magnetic gap MS during the transition from the first switching state to the second switching state, i.e., can move along a path having a length MS, where MS is at least equal to SW, and particularly preferably MS > SW. The path along which the contact element has to move so as to lose or gain mechanical contact with at least two auxiliary contacts can be referred to as the contact path KW. The contact path KW is preferably smaller than the switching path SW and smaller than the magnetic gap MS. Particularly preferably, KW < SW and KW < MS. The mechanical drive, and thus preferably the magnet armature, can also move the distance MS during the transition from the second switching state to the first switching state, and the contact element can lose mechanical contact with at least two auxiliary contacts preferably after a distance of 0.2×MS or less, or 0.1×MS or less, if the contact element is in contact with the auxiliary contacts in the second switching state of the switching device.

[0045] In the switching device described herein, it can be achieved that at least two auxiliary contacts are electrically connected to each other by the contact element in the first switching state and electrically separated from each other in the second switching state. By measuring the electrical resistance between the auxiliary contacts, the first switching state, which particularly preferably corresponds to the non-connected switching state, can be reliably determined. The above-described embodiment of the switching device enables the detection of a fault state according to IEC60947-5-1, i.e., a state in which the switching device cannot be closed, i.e., a state in which the switching device is blocked in the open position. Furthermore, even if the upper part of the switching device in which the switching chamber is arranged is damaged, the detection that the switching device is in the non-connected state and thus that the switching contacts are open can still be performed.

[0046] Alternatively, in the above-mentioned reverse embodiment, it can be achieved that at least two auxiliary contacts with contact elements indicate the switching state of the main contacts, i.e. the movable contact and at least one fixed contact, in which case the state of the auxiliary contacts, i.e. electrically connected to one another or electrically separated from one another, preferably always corresponds to the state of the main contacts.

[0047] The switching device described herein can furthermore be manufactured very cheaply, i.e., without significant additional costs, since no additional electronic components, for example in the form of additional circuits and / or ICs, are required. Furthermore, there is no magnetic influence on the auxiliary contact and the monitoring contact formed by the contact element, as is the case, for example, with reed switches or Hall switches. In addition, it can be ensured that the mechanical influence of the monitoring contact due to an impact follows the characteristics of the moving system, i.e., the monitoring contact also accurately indicates its "not fully opened" state after lift-off due to acceleration. Since the auxiliary contact is not located within the switching chamber, arcs occurring there cannot damage the device forming the monitoring contact. On the other hand, the components used do not adversely affect the arc-extinguishing behavior within the switching chamber.

[0048] Further advantages, advantageous embodiments and developments will become apparent from the examples described below in conjunction with the drawings. [Brief explanation of the drawings]

[0049] [Figure 1A] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1B] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1C] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1D] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1E]1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1F] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1G] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 1H] 1 is a schematic diagram of a switching device and a portion thereof according to an embodiment; [Figure 2A] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 2B] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 2C] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 2D] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 3A] 1A-1H in an intermediate state. [Figure 3B] 1A-1H in an intermediate state. [Figure 4A] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 4B] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 4C] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 4D] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 4E] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 4F] 4 is a schematic diagram of a switching device and part thereof according to a further embodiment; [Figure 5A] 5 is a schematic diagram of an auxiliary contact of a switching device according to a further embodiment; [Figure 5B] 5 is a schematic diagram of an auxiliary contact of a switching device according to a further embodiment; [Figure 6A] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 6B] 4 is a schematic diagram of a part of a switching device according to a further embodiment; [Figure 6C] 4 is a schematic diagram of a part of a switching device according to a further embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0050] In the examples and figures, identical, similar, or equivalently functioning elements may be respectively provided with the same reference numerals. The illustrated elements and their size ratios relative to one another are not to scale; rather, individual elements, such as layers, components, members, and regions, may be shown exaggeratedly large for better illustration and / or understanding.

[0051] 1A-1H show an embodiment of a switching device 100, which can be used, for example, to switch high currents and / or high voltages and can be a relay or a contactor, in particular a power contactor. In FIGS. 1A and 1F, the switching device 100 is shown in cutaway views along a vertical section, respectively, in different switching states. In FIGS. 1B and 1G, the switching device 100 is shown in cutaway views along a further, orthogonal vertical section, respectively, in corresponding switching states. In FIGS. 1C and 1H, a portion of the view shown in FIGS. 1A and 1F is shown. In FIGS. 1D and 1E, a view of a portion of the hermetic area of ​​the switching device 100 is shown. It should be understood that the illustrated geometries are merely exemplary and not limiting, and may be designed differently.

[0052] The switching device 100 comprises two fixed contacts 1 and one movable contact 2 in a housing (not shown). The movable contact 2 is designed as a contact plate. The fixed contact 1 together with the movable contact 2 form the switching contact of the switching device 100, which may also be called the main contact, by means of which a load circuit connectable to the fixed contact 1 can be opened or closed. Instead of the number of switching contacts shown, other numbers of fixed and / or movable contacts may also be possible. Furthermore, it should be understood that the illustrated embodiments of the switching contacts and in particular their geometrical shape are purely exemplary and not limiting. Alternatively, the switching contacts may also be designed in other ways.

[0053] Preferably, the housing (not shown), in which all the illustrated components of the switching device 100 are arranged except for the upper part of the respective fixed contact 1, functions mainly as contact protection for the components arranged therein and comprises or consists of a plastic, such as polybutylene terephthalate (PBT) or glass-fiber-filled PBT. The fixed contact 1 and / or the movable contact 2 can comprise or consist of, for example, 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, a mixture of copper and at least one other metal, such as Wo, Ni and / or Cr.

[0054] 1A-1C, the switching device 100 is shown in an idle state in which the movable contact 2 is separated from the fixed contact 1, and therefore the contacts 1 and 2 are electrically isolated from each other. The idle state is also referred to below as a first switching state, which is a disconnected state of the switching device 100. Thus, the load circuit connected to the fixed contact 1 of the switching device 100 is open in this switching state. In FIGS. 1F-1H, the switching device 100 is shown in a second switching state, which is a connected state of the switching device 100. In the second switching state, the fixed contact 1 and the movable contact 2 are in mechanical contact with each other and therefore electrically connected, and as a result, the load circuit connected to the switching device 100 is closed.

[0055] To perform the switching movement, the switching device 100 has a mechanical drive, which in the illustrated embodiment is designed purely exemplarily as a lift drive, so that the movable contact 2 performs a linear movement, which in the illustrated embodiment runs along a vertical direction 91, when switching from a first switching state to a second switching state and vice versa. In particular, the mechanical drive is designed as a magnetic drive and has a movable magnet armature 5 that essentially performs the switching movement. The magnet armature 5 has a magnetic core 6, which may for example include or consist of a ferromagnetic material. Furthermore, the magnet armature 5 has a shaft 7 that runs through the magnetic core 6 and is firmly connected to the magnetic core 6 at one axial end. At the other axial end opposite the magnetic core 6, the magnet armature 5 is supported via a contact spring 70 and has the movable contact 2, which is also connected to the shaft 7. The shaft 7 preferably includes or can be made of stainless steel. To electrically insulate the movable contact 2 from the shaft 7, an electrically insulating contact holder 71, which may also be called a bridge insulator, may be arranged between them.

[0056] The magnetic core 6 is surrounded by a coil 8, which forms an essential part of the electromagnet. A current in the coil 8, which can be connected externally via a control circuit, causes a movement of the magnetic core 6, and thus of the entire magnetic armature 5, in the axial direction, i.e., in the main direction of extension of the shaft 7, and thus in the vertical direction 91, so that the movable contact 2 comes into contact with the fixed contact 1. In the illustrated example, the magnetic armature 5 moves upwards. Thus, the magnetic armature 5 moves from a first position, which corresponds to the illustrated idle state and simultaneously to the disconnected or non-connected state and thus to the switched-off state, to a second position, which corresponds to the active or connected and therefore switched-on state of the switching device 100.

[0057] To guide the shaft 7 and thus the magnet armature 5 and to form a magnetic circuit together with the magnetic core 6 and the coil 8, the switching device 100 further comprises a yoke 9, which may contain or consist of pure iron or a lightly doped iron alloy and form part of the magnetic circuit. The yoke 9 has an opening through which the shaft 7 is guided. Furthermore, an additional sleeve or bushing, for example, made of a plastic material, may be arranged in the opening of the yoke 9 to guide the shaft 7. When the current in the coil 8 is interrupted, the magnet armature 5 is again moved to the first position by the return spring 10. Thus, in the illustrated example, the magnet armature 5 moves downward again. The switching device 100 is then again in an idle state with the contacts 1 and 2 open. Instead of a single return spring 10, multiple return springs may be present, each of which may act like an effective return spring with an effective return spring force.

[0058] The direction of movement of the magnetic armature 5, and thus of the movable contact 2, is, as mentioned above, referred to as the vertical direction 91. Terms such as "up" or "down" refer to the vertical direction 91 unless otherwise specified. In this sense, the magnetic armature 5, and thus the movable contact 2, move upward during the transition of the switching device 100 from the first switching state to the second switching state and move downward again during the transition from the second switching state to the first switching state. A plane perpendicular to the vertical direction 91 is referred to as a horizontal plane. A direction perpendicular to the vertical direction 91 may generally be referred to as a horizontal direction. In this case, the horizontal direction along which the fixed contact 1 is arranged is also referred to as a longitudinal direction 92. A horizontal direction perpendicular to the vertical direction 91 and perpendicular to the longitudinal direction 92 is also referred to as a transverse direction 93. The directions 91, 92, and 93, which are valid regardless of the switching movement described, are shown in the figures to facilitate orientation.

[0059] For example, when contacts 1 and 2 are opened, at least one arc may occur, potentially damaging the contact surfaces of contacts 1 and 2. This could result in the contacts 1 and 2 becoming "stuck" together and no longer separating due to welding caused by the arc. In this case, switching device 100 remains switched on, even though the current in coil 8 must be switched off and the load circuit must be disconnected. To prevent such an arc from occurring, or at least to facilitate its extinguishing, contacts 1 and 2 are located in a gas atmosphere. Consequently, switching device 100 is designed as a gas-filled relay or contactor. For this purpose, contact 1 is located inside switching chamber 11, which is formed by switching chamber cover 12 and switching chamber bottom 13. This gas-tight region 14 is essentially formed by switching chamber 11 and part of yoke 9, as well as additional wall regions 21 and 22. The gas-tight region 20 completely surrounds the magnetic armature 5 and the contacts 1, 2, except for the portion of the fixed contact 1 provided for external connection. The gas-tight region 20, and thus also the interior space 14 of the switching chamber 11, is filled with gas. The gas that can be filled into the gas-tight region 20 during the manufacture of the switching device 100, for example through a gas filling nozzle in the switching chamber cover 12, is preferably a hydrogen-containing gas, for example, containing 20% ​​or more H2 in an inert gas, or 100% H2, since this gas can facilitate arc extinction.

[0060] There may additionally be present, inside or outside the switching chamber 11, for example permanent magnets (not shown) intended and adapted to deflect the arc, so-called blow-out magnets, which in particular may result in an extension of the arc path and thus improve the extinction of the arc.

[0061] The switching chamber cover 12 may be made of or from a ceramic material, for example a metal oxide such as Al2O3. The switching chamber bottom 13 is formed in the illustrated embodiment by a flange 15, inside which the yoke 9 is arranged and which forms part of the magnetic circuit. The flange 15 may comprise or consist of iron or steel. The switching chamber bottom 13 may alternatively be formed by an additional component between the switching chamber cover 12 and the flange 15, as will be explained below.

[0062] Furthermore, the switching device 100 has at least two auxiliary contacts 3 arranged outside the switching chamber 11. In particular, the at least two auxiliary contacts 3 are arranged outside the switching chamber 11 on the opposite side of the mechanical drive, and thus of the shaft 7, from the movable contact 2. Instead of the illustrated embodiment with two auxiliary contacts 3, the switching device 100 can have three or more auxiliary contacts 3, to which the following explanation applies. The auxiliary contacts 3 can be arranged along the longitudinal direction 92, as shown in Figures 1A to 1H, similar to the fixed contact 1. Alternatively, the auxiliary contacts 3 can be arranged along another transverse direction, for example along the transverse direction 93, or along a direction between the longitudinal direction 92 and the transverse direction 93.

[0063] The switching device 100 further comprises at least one contact element 4 arranged outside the switching chamber 11. In particular, the contact element 4 is arranged outside the switching chamber 11 on the opposite side of the mechanical drive, and thus of the axis 7, to the movable contact 2. The contact element 4 is movable together with the movable contact 2. The contact element 4 and the movable contact 2 are in particular movable by the same mechanical drive as described above. The contact element 4 is arranged inside the gas-tight region 20.

[0064] The gas-tight region 20 essentially comprises an upper region 28 formed above the flange 15 by the switching chamber 11, and a lower region 29 arranged below the flange 15 and in which the magnetic core 6 of the magnet armature 5 is arranged. The auxiliary contact 3 and the contact element 4 are therefore arranged in the lower region 29 of the gas-tight region 20.

[0065] 1A-1C, the contact element 4 contacts at least two auxiliary contacts 3 in the first switching state of the switching device 100. Therefore, the contact element 4 is in mechanical and therefore electrical contact with the at least two auxiliary contacts 3 in the first switching state. In the second switching state, the contact element 4 is spaced apart from the auxiliary contacts 3, as can be seen in FIGS. 1F-1H. Therefore, the contact element 4 can contact the auxiliary contacts 3 when the switching device 100 is in the idle state and the movable contact 2 is spaced apart from the fixed contact 1. On the other hand, the contact element 4 is spaced apart from the at least two auxiliary contacts 3 when the movable contact 2 of the switching device 100 contacts the fixed contact 1 and the switching device 100 is in the connected state.

[0066] By means of the contact elements 4, at least two auxiliary contacts 3 are electrically connected to one another and thus short-circuited. That is, when electrical contact is detected between the auxiliary contacts 3, this means that the switching device 100 is in a disconnected state. The auxiliary contacts 3 and the contact elements 4 thus form a monitoring contact with a "normally closed" characteristic. Alternatively, it is also possible for the first switching state to be a connected switching state and the second switching state to be a disconnected state. In this case, the operating principle of detecting the state of the switching device via the auxiliary contacts is designed inversely and corresponds to a "normally open" implementation.

[0067] The auxiliary contacts 3 are arranged in the ceramic element 30 and protrude through it. For this purpose, the ceramic element 30 has openings in which an auxiliary contact 3 is arranged, and which are particularly preferably hard soldered to the edge of the respective opening 39. The auxiliary contacts 3 can, for example, have a flange with a fixing area that is attached to the ceramic element 30 by means of a solder, for example a hard solder. The auxiliary contacts 3 are electrically insulated from one another by the ceramic element 30. The ceramic element 30 can, for example, consist of a metal oxide, such as Al2O3.

[0068] The ceramic element 30 in particular forms part of the wall of the gas-tight region 20. Adjacent to the ceramic element 30, the gas-tight region 20 has a wall region 22 that comprises or consists of stainless steel and is hermetically soldered or welded to the ceramic element 30 by hard solder. For this purpose, the wall region 22 can comprise or consist of, for example, nickel-plated stainless steel. The ceramic element 30 is formed, for example, as a ceramic plate, i.e., as a ceramic disk with, for example, a circular cross section in the transverse plane. To fix the auxiliary contact 30 and the wall region 22, the ceramic elements can each have mounting regions formed, for example, by raised circumferential surface regions, as can be seen, for example, in FIGS. 1C and 1H.

[0069] The auxiliary contact 3 and / or the contact element 4 may comprise or consist of a material containing copper or a copper alloy. Particularly preferably, the material has good electrical conductivity and poor welding tendency. Particularly preferably, the material may be selected from CuBe, CuSn4, CuSn6. Furthermore, for example, the auxiliary contact 3 may comprise the same material as the fixed contact 1 and / or the movable contact 2.

[0070] The ceramic element 30 and the wall region 22 connected thereto together form a cup shape in the embodiment shown, the ceramic element 30 being substantially disk-shaped as described above and forming the bottom of the cup shape, while the wall region 22 connected to the ceramic element 30 has a cylindrical portion forming the side wall of the cup shape, within which the magnetic core 6 in particular can be guided.

[0071] The ceramic element 30 is intended and adapted to hermetically seal the lower part of the gas space formed by the gas-tight region 20, as described above, and to electrically insulate the auxiliary contacts 30 from each other and from any other potentials within the switching device 100. The laying of the auxiliary contacts 3 in the gas-tight region 20 is carried out by means of hermetically sealed and particularly preferably hard-soldered joints from the wall region 22, which may also be referred to as a pot, towards the ceramic element 30, and from the ceramic element 30 towards the auxiliary contacts 3. The above-mentioned solder joints can be carried out in a conventional process step. The pot formed by the wall region 22, with the ceramic element 30 and the auxiliary contacts 3, can then be welded to the flange 15, for example by laser welding, to form the lower region 29 of the gas-tight region 20.

[0072] The contact element 4 is particularly preferably formed in one piece. As can be seen in the figure, the contact element 4 can be formed, for example, in the form of a metal band or strip, particularly preferably in the form of a spring sheet strip. In particular, the contact element 4 has a contact web 40, two connecting webs 41 extending away from the contact web 40, and a contact plate 42 adjoining each of the connecting webs 41. The connecting webs 41 particularly preferably extend away from the contact web 40 at an angle of substantially 90° and can have, for example, the same width as the contact web 40. The connecting webs 41 and the contact webs 40 can therefore be formed by a metal strip or band having a uniform width and bent into a rectangular U-shape. Each connecting web 41 has a contact plate 42 at its end opposite the contact web 40, which is particularly preferably inclined relative to the corresponding connecting web 41 and may subtend an angle with the corresponding connecting web of, for example, 90° or more, or 10° or more, and 160° or less, or 140° or less, or 135° or less. For example, each contact plate may subtend an angle of 110° with the connecting web on which it is arranged. The contact plate 42, which is intended and adapted to establish mechanical contact with the auxiliary contact 3 in the first switching state, preferably has a width equal to or greater than the width of the connecting web 41. As shown, the contact plate 42 is particularly preferably formed semicircular, so that as large an area as possible of the contact element 30 can be covered by the contact plate 42 without the contact plates 42 coming into direct mechanical contact with each other. In particular, the contact plates 42 face each other and are spaced apart from each other by a distance A that is smaller than the width B of the auxiliary contact 3, i.e., in particular, smaller than the width of the contact surface of the auxiliary contact 3 that contacts the contact element 4. In that case, the width B of the auxiliary contact 3 is preferably measured in the direction along which the distance A of the contact plate 42 is also measured, i.e. along the longitudinal direction 92 in the orientation shown in Figures 1A to 1H.

[0073] The contact elements 4 can be fixed, for example, directly to the shaft 7. Preferably, the contact elements 4 are fixed to the magnetic core 6. In this case, it is particularly preferred that the contact elements 4 are fixed directly to the magnetic core 6. For example, the contact elements 4 can be welded to the shaft 7 or preferably to the magnetic core 6, for example by laser welding or resistance welding. In particular, the contact elements 4 can be welded to the contact webs 40. The magnetic core 6 can have, as shown, a recess 60 in which part of the contact elements 4, in particular the contact webs 40, are arranged. The connecting webs 41 can protrude from the recess 60.

[0074] Due to the above-mentioned design of the mechanical drive, the coil 8 has a continuous cylindrical opening, which forms a cavity in which the magnetic core 6 is arranged. In particular, the above-mentioned cup is arranged in a inserted state inside the coil 8. The contact element 4 and the auxiliary contact 3 are therefore also arranged in the continuous cylindrical opening and are surrounded by the coil 8. The cavity in the coil 8 which is present due to the construction can therefore be used for the auxiliary contact 3 and the monitoring contact formed by the contact element 4 without requiring additional space. The small installation space in the coil opening which is present below the switching chamber 11 can therefore be optimally utilized.

[0075] The contact element 4 is at least partially spring-shaped and thus has spring-like and therefore elastic properties. Because the contact element 4 is formed by a spring sheet, and thus by a plate-like and / or band-like sheet, at least in the region of the connecting web 41 and / or the contact plate 42, it can be bent by the action of a force and can return to its original shape in the absence of this force. Due to the above-mentioned gap with distance A, the contact plate 42, when placed on the auxiliary contact 3, is pressed in the direction of the contact web 40 and can therefore bend. In the first switching state, the contact element 4 therefore exerts a force on the auxiliary contact 3 by spring pressure, thereby achieving a reliable mechanical contact that can be maintained even in the event of vibrations or shocks.

[0076] As described above, the mechanical drive designed as a lift drive has a return spring 10 that causes the movement of the magnet armature 5 from the second switching position back to the first switching position in the switched-off electromagnet, i.e., when the coil 8 is switched off. The return spring 10 has a return spring force RFK. If there are multiple return springs, they can be treated as one return spring having an effective return spring force RFK. In order to enable a complete return of the magnet armature 5 to its idle position, it is necessary that the contact element has a spring force FK that is smaller than the return spring force RFK of the return spring, i.e., FK < RFK holds. Preferably, the spring force of the contact element 4 is significantly smaller than the return spring force of the return spring 10, such that, for example, FK / RFK < 0.5 holds and the switching movement is not restricted by the contact element. Particularly preferably, FK / RFK ≦ 0.2 holds.

[0077] As can be seen in FIGS. 1D, 1E, and 2A-2D, the above-described substantially rotationally symmetrical structure of the contact plates 42, which are spaced a small distance A from one another, ensures that the positioning of the auxiliary contacts 3 relative to the contact element 4 plays no role. This is because it is guaranteed that the auxiliary contacts 3 can be short-circuited by the contact element 4 at each relative rotation of the contact element 4 relative to the auxiliary contact 3 about the vertical axis. While FIGS. 1C and 1D show an arrangement of the contact element 4 that is not rotated relative to the auxiliary contact 3, FIGS. 2A and 2B show a 45° rotation relative to the non-rotated arrangement, and FIGS. 2C and 2D show a 90° rotation relative to the non-rotated arrangement. Even in the case of a 90° rotation, as shown in FIG. 2D, the width B of the auxiliary contacts 3 is smaller than the distance A of the contact plates 42, ensuring that the auxiliary contacts 3 can be electrically connected to one another by the contact element 4. This allows for simplified assembly of the components of the switching device 100, since the varying end positions of the magnetic armature 6 can be taken into account. Therefore, instead of the lift drive described above, the mechanical drive can be, for example, a rotary drive. Such a rotary drive is described in DE 10 2019 126 351 A1, the disclosure of which is incorporated herein by reference in its entirety. Instead of the auxiliary contacts in the switching chamber described in DE 10 2019 126 351 A1, the auxiliary contacts and contact elements described herein can be used outside the switching chamber, for example, at the lower end of the shaft. Even in such an embodiment, the semicircularly shaped contact plate 42 formed by the contact spring seat is important because it can always establish contact with the auxiliary contact 3, regardless of the rotation of the armature.

[0078] As shown in FIG. 1A, the movable contact 2 must move along a switching path SW during the transition from the first switching state to the second switching state to close the switching gap. The path along which the magnetic armature 5 moves is provided by the magnetic gap MS between the magnetic core 6 and the yoke 9 in the idle position, as shown in FIG. 1B. The path along which the magnetic armature 5, and thus the contact element 4, must move to lose mechanical contact with at least two auxiliary contacts 3 can be referred to as the contact path KW and is shown in FIG. 1H. The greater the deformation of the contact element 4 in the first switching state of the switching device 100, the larger the contact path KW. Only after the contact element 4 has completely returned to its undeflected state can the contact element reliably lose contact with the auxiliary contacts 3. The contact path KW is preferably significantly smaller than the switching path SW and smaller than the magnetic gap MS in the idle position. This ensures that the distance the movable system must travel before contact between the auxiliary contacts and the contact elements is broken is as small as possible. Particularly preferably, KW / SW≦0.2 holds.

[0079] The magnetic armature with the movable contact 2 shown in FIGS. 1A-1H is an overstroke system in which the movable contact 2 is displaceably mounted in a contact holder 71. When the movable contact 2 abuts against the fixed contact 1, thus completely closing the switching gap, the contact spring 70 can be compressed, allowing the magnetic armature 5 to move further, for example, until the magnetic core 6 contacts the yoke 9 and the magnetic gap MS shown in FIG. 1B is completely closed. For example, the magnetic core 6 can move further above the movable contact 2 in the vertical direction 91 by a distance of less than 1 mm, particularly preferably about 0.5 mm. The overstroke compression of the contact spring 70 increases the contact pressure of the movable contact 2 against the fixed contact 1, achieving a certain degree of insensitivity to vibrations and mechanical shocks. Therefore, preferably, KW / MS≦0.2, where MS represents the magnetic gap in the first switching state.

[0080] If the switching device 100 is returned to the first switching state in the second switching state and the contacts 1, 2 are stuck, i.e., the movable contact 2 is welded to at least one of the fixed contacts 1 (also known as "tack welding"), the movable contact 2 remains connected even though the coil 8 is switched off. The return spring 10 only reduces the overstroke, resulting in a small magnetic gap MSK between the magnetic core 6 and the yoke 9, while the switching gap remains closed. This state is shown in FIGS. 3A and 3B, views corresponding to FIGS. 1A and 1B. The magnetic armature 5 remains in this state, thus forming an intermediate state. Due to the aforementioned short contact path of the contact element 4, the auxiliary contact 3 is still separated from the contact element 4, so that it can be reliably detected at the auxiliary contact 3 that the first switching state has not yet been reached. This allows a malfunction of the switching device 100 to be reliably detected. The switching device 100 described above therefore satisfies the above-mentioned criteria requirement of detecting the "safely open" condition by a simple mechanism for detecting and outputting a signal from the sealed gas space in the lower region 29 of the switching device 100. In that case, the auxiliary contact 3 is protected from flashover due to arcing in the upper region 28, i.e. in the switching chamber 11.

[0081] 4A to 4F show further embodiments of the switching device 100. In FIG. 4A, the switching device 100 is shown in a cutaway view along a vertical section. In this view, the switching device 100 is in a first switching state. In FIG. 4B, the switching device 100 is shown in a second switching state. In FIGS. 4C and 4D, cross sections of the switching device 100 are shown in cutaway views in the first and second switching states, respectively. FIGS. 4E and 4F show the auxiliary contact 3 and the contact element 4 of the switching device 100. The following description applies equally to FIGS. 4A to 4F, and mainly describes the differences from the previous embodiment. Features and components not described below can be formed according to the previous description.

[0082] 4A to 4F, like the switching device 100 described above, has as switching contacts two fixed contacts 1 and one movable contact 2 formed as a contact plate in a housing designated by the reference number 19. Preferably, the housing 19, in which all further illustrated components of the switching device 100 except for the upper parts of the respective fixed contacts 1 are arranged, serves primarily as contact protection for the components arranged therein and may be formed as described above.

[0083] 4A and 4C show switching device 100 in an idle state in which movable contact 2 is separated from fixed contact 1, which in this embodiment is also referred to as a first switching state, which is a disconnected state of switching device 100. In Figures 4B and 4D, switching device 100 is in a second switching state, which is a connected state of switching device 100.

[0084] The switching chamber bottom 13, in comparison with the previous embodiment, is designed as an additional element and is arranged on a flange 15 in which the yoke 9 is arranged. Thus, in comparison with the switching device 100 described above, the switching chamber bottom 13 can be formed by a component between the switching chamber cover 12 and the flange 15, as shown, which preferably covers the flange 15 and has an opening through which the shaft 7 protrudes. For such a switching chamber bottom, ceramic materials or plastics with particularly high enough temperature resistance, such as polyetheretherketone (PEEK), polyethylene (PE) and / or glass-fiber-filled PBT, are suitable. Alternatively or additionally, the switching chamber 11, in particular the switching chamber bottom, can be at least partly made of ceramic, in particular of the structure (CHO). n Such plastics may also include polyoxymethylene (POM) having a relatively low carbon content and a very low tendency to form graphite. In particular, (CHO) n In this case, the same carbon and oxygen content can lead to the evolution of mainly gaseous CO and H2 during thermally induced, and especially arc-induced, decomposition. The additional hydrogen can enhance arc extinction.

[0085] Furthermore, the switching device 100 has at least two auxiliary contacts 3 and at least one contact element 4 arranged outside the switching chamber 11, as explained in connection with the previous embodiment. The auxiliary contacts 3 are arranged in the openings 39 of the ceramic element 30 as described above and protrude through the ceramic element 30. An auxiliary contact 3 is arranged in each opening 39, and the auxiliary contacts are particularly preferably hard soldered to the edge of the respective opening 39. As shown based on the schematic diagram of the auxiliary contacts 3 in Fig. 4E, the auxiliary contacts 3 have a flange 35 with a fixing region 36 fixed to the ceramic element 30. The fixing region 36 of each auxiliary contact 3 is therefore soldered to the ceramic element 30 in the edge region around the respective opening 39.

[0086] 4A to 4D, ceramic element 30 may further have a further opening in which gas fill nozzle 18 is arranged, particularly preferably also soldered, and via which gas-tight region 20 can be filled with gas as described above within the scope of manufacturing switching device 100. Gas fill nozzle 18 can be closed after filling, for example by soldering or crushing.

[0087] As explained in connection with the previous embodiment, the contact element 4 is particularly preferably formed in one piece. As can be seen in particular in FIG. 4F , the contact element 4 of the embodiment of FIGS. 4A-4F can have a contact ring 43 instead of the contact webs described above. Furthermore, as in the previous embodiment, the contact element 4 has at least two connecting webs 41 and a contact plate 42 in contact with each of the connecting webs 41. The connecting webs 41 extend away from the contact ring 43. Even though the contact element 4 is always described here and below with a contact ring 43, instead of the contact ring 43, there may be contact webs as described above that linearly connect the connecting webs 41 or a contact plate formed, for example, as a circular disk. In particular, the features described below for the contact ring 43 may also apply to the contact webs or the contact plate.

[0088] At least parts of the contact elements 4, such as the connecting webs 41 and the contact plates 42, or even the entire contact element 4, can be formed from spring sheets, as described above. The contact ring 43 is preferably formed flat and can have a main extension plane. The connecting webs 41 particularly preferably extend at an angle of substantially 90° away from the main extension plane and thus away from the contact ring 43. Thus, the connecting webs 41 and the contact ring 43 can be formed by a metal part with the contact ring 43 comprising at least two strips arising from the contact ring 43, which strips are bent away from the main extension plane of the contact ring 43 and preferably enclose an angle of 90° or at least substantially 90° with the main extension plane of the contact ring 43. Each connecting web 41 has a contact plate 42 at its end opposite the contact ring 43, which is particularly preferably inclined relative to the corresponding connecting web 41 and may subtend an angle with the corresponding connecting web of, for example, 90° or more, 100° or more, and 160° or less, 140° or less, or 135° or less. For example, each contact plate may subtend an angle of 110° with the connecting web on which it is arranged. The contact plate 42, which is intended and adapted to establish mechanical contact with the auxiliary contact 3 in the second switching state, preferably has a width equal to or greater than the width of the connecting web 41. As shown, the contact plates 42 are particularly preferably formed semicircular. In particular, the contact plates 42 face each other.

[0089] The contact element 4 is fixed to the magnetic core 6, as in the previous embodiment. In particular, the contact element 4 may be welded to the magnetic core 6, for example by means of a contact ring 43. The magnetic core 6 may have an annular raised area, as shown, on which the contact ring 43 is arranged and fixed.

[0090] Unlike the previous embodiment, the contact element 4 in the first switching state of the switching device 100 does not contact and is therefore separated from the at least two auxiliary contacts 3, as can be seen in FIGS. 4A and 4C . Therefore, the contact element 4 is not in mechanical and therefore electrical contact with the at least two auxiliary contacts 3 in the first switching state. In the second switching state, the contact element 4 contacts and is therefore in mechanical and electrical contact with the auxiliary contacts 3, as can be seen in FIGS. 4B and 4D . Therefore, the contact element 4 is separated from the at least two auxiliary contacts 3 when the switching device 100 is in the idle state and the movable contact 2 is separated from the fixed contact 1. On the other hand, the contact element 4 can contact the auxiliary contacts 3 when the movable contact 2 of the switching device 100 contacts the fixed contact 1 and the switching device 100 is in the connected state. The contact element 4 electrically connects the at least two auxiliary contacts 3 to each other and thus short-circuits them. That is, when electrical contact is detected between the auxiliary contact 3, this means that in the illustrated embodiment the switching device 100 is in a connected state. The auxiliary contact 3 and the contact element 4 thus form a monitoring contact which has a "normally open" characteristic and which indicates the state of the main contacts 1, 2.

[0091] 4C and 4D, in the first switching state of the switching device 100, at least a portion of the contact element 4 is arranged laterally adjacent to the at least two auxiliary contacts 3. In particular, at least a portion of the contact plate 42 and the connecting web 41 can be arranged laterally adjacent to the auxiliary contacts 3. Each of the at least two auxiliary contacts 3 has an upper end 31 facing the axis 7, and the contact plate 42 is arranged below the upper end 31 as viewed from the axis 7, regardless of the switching state of the switching device 100, i.e., in both the first and second switching states. In other words, the upper end 31 of each auxiliary contact 3 is arranged above the contact plate 42 in the vertical direction 91. Each of the auxiliary contacts 3 has a contact area 32, as shown in FIG. 4E. The contact areas 32 of the auxiliary contacts 3 are arranged at the upper end 31 and are mechanically and therefore electrically contacted by the contact plates 42 of the respective contact elements 4 in the second switching state of the switching device 100, as shown in Figures 4B and 4D. At least in the second switching state of the switching device 100, each of the contact areas 32 is arranged between a contact ring 43 and the contact plates 42, which are in mechanical contact with the contact areas 32. Since the contact plates 42 are arranged below the upper end 31, the contact areas 32 of the auxiliary contacts 3 face downwards and are therefore away from the axis 7.

[0092] 4A to 4E, the contact area 32 of the auxiliary contact 3 can be formed in the form of a conical surface. Due to the arrangement of the contact plate 42 inclined relative to the connecting web 41 described above, a good mechanical and therefore electrical contact can be achieved between the auxiliary contact 3 and the contact element 4.

[0093] Opposite the upper end 31, each auxiliary contact 3 has a lower end 33 adjacent to the flange 35 and having a connection area 34, via which each of the auxiliary contacts 3 can be connected via a power supply line outside the gas-tight area 20. The distance of the contact area 32 of each auxiliary contact 3 from the ceramic element 30 is determined essentially by the length of the connection area 37 between the upper end 31 and the lower end 33. During a switching operation of the switching device 100, the contact plates 42 move along the connection area 37 of the auxiliary contacts 3 until they each come into contact with the contact area 32.

[0094] As explained in connection with the previous embodiment, the contact element 4 is at least partially spring-shaped and thus has spring-like, and therefore elastic, properties. Because the contact element 4 is formed by a spring sheet, and thus a plate-like and / or band-like plate, at least in the region of the connecting web 41 and / or the contact plate 42, it can bend under the action of a force and return to its original shape in the absence of this force. During the transition of the switching device 100 from the first to the second switching state, the contact plate 42 is pushed aside by the contact ring 43 when it rests on the auxiliary contact 3, i.e., in particular on the contact area 32 of the auxiliary contact 3, and upon further movement of the contact element 4. This allows the contact plate 42 and / or the connecting web 41 to bend elastically, so that the contact plate 42 is pressed against the contact area 32. In the second switching state, the contact element 4 therefore exerts a force on the auxiliary contact 3 by spring pressure, thereby achieving a reliable mechanical contact that can be maintained even in the event of vibrations or shocks.

[0095] As described above, the mechanical drive designed as a lift drive has a return spring 10 with a return spring force RFK, which causes the magnet armature 5 to return from the second switching position to the first switching position when the electromagnet is switched off. The contact element 4 may have a spring force FK. Preferably, FK < RFK, particularly preferably FK / RFK ≦ 0.2 holds, so that the switching movement is not affected or at least not substantially affected by the contact element, and the spring force of the contact element does not interfere with the action of the force of the mechanical drive during the transition from the first switching operation to the second switching operation. Thereby, it may be possible for the return spring 10 and the mechanical drive to be optimally designed regardless of whether the auxiliary contact 3 and the contact element 4 are incorporated in the switching device 100 or not.

[0096] As described in relation to the previous embodiment and as also shown in FIG. 4A, in order to close the switching gap as shown in FIG. 4B, the movable contact 2 must move along the switching path SW during the transition from the first switching state to the second switching state. In that case, the path along which the magnetic armature 5 moves is given by the magnetic gap MS between the core 6 and the yoke 9 in the idle position, as shown in FIG. 1C. The path along which the magnetic armature 5, and thus the contact element 4, must move so that the contact element 4 mechanically contacts at least two auxiliary contacts 3 can also be referred to as the contact path KW in this embodiment and is also shown in FIG. 4C. The contact path KW is preferably smaller than the switching path SW and smaller than the magnetic gap MS in the idle position. Thereby, after contact is established between the auxiliary contact 3 and the contact element 4, the movable system can move further, and thus, the contact plate 42 can be pressed against the contact area 32 of the auxiliary contact 3, as described above, can be achieved. Particularly preferably, KW < SW and KW < MS hold. The mechanical drive, and thus preferably the magnetic armature 5, can also travel the distance MS during the transition from the second switching state to the first switching state, and the contact element 4 can lose mechanical contact with at least two auxiliary contacts 3 after a distance preferably less than or equal to 0.2×MS or less than or equal to 0.1×MS.

[0097] The magnetic armature 5 having the movable contact 2 is also an overstroke system in this embodiment, in which the movable contact 2 is displaceably arranged in the contact holder 71. When the movable contact 2 hits the fixed contact 1, thus when the switching gap is completely closed, as already explained in connection with the previous embodiment, the contact spring 70 can be compressed and the magnetic armature 5 can move further, for example, as shown in Fig. 4D, until the magnetic core 6 contacts the yoke 9 and the magnetic gap MS shown in Fig. 4B is completely closed. Particularly preferably, the magnetic core 6 can move further upward in the vertical direction 91 by a distance of 1 mm or less, particularly preferably about 0.5 mm, relative to the movable contact 2. As a result, due to the compression of the contact spring 70 caused by the overstroke, the contact pressure of the movable contact 2 against the fixed contact 1 can be increased, and a certain insensitivity to vibrations and mechanical shocks can be achieved.

[0098] When the switching device 100 should return to the first switching state in the second switching state and the contacts 1, 2 are stuck, only the overstroke can be reduced as described above. As a result, only a small magnetic gap MSK is generated between the magnetic core 6 and the yoke 9, while the switching gap remains closed and the magnetic armature 5 remains stuck in this intermediate state. Due to the above-described contact path KW of the contact element 4, which is smaller than the size of the magnetic gap MS in the first switching state, the auxiliary contact 3 is preferably still contacted by the contact element 4. As a result, it can be reliably detected that the second switching state still exists at the auxiliary contact 3 and the first switching state has not yet been reached. The contact element 4 loses mechanical contact with the auxiliary contact 3 only after the magnetic core 6 has advanced a distance MS-KW during the downward movement of the magnetic armature 5, i.e., in the direction from the second switching state to the first switching state. Therefore, it is particularly preferable that MSK < MS-KW holds. Thereby, a malfunction of the switching device 100 can be reliably detected.

[0099] 4A-4F, like the previous embodiment, has a simple mechanism for detecting the switching state and outputting a signal from a hermetically sealed gas space in the lower region 29 of the switching device 100. In this embodiment too, the auxiliary contact 3 is then protected from flashover due to arcing in the upper region 28, i.e. in the switching chamber 11.

[0100] 5A and 5B, the contact area 32 of each auxiliary contact 3 can have a conical surface shape different from that described in connection with the embodiment of FIGS. 4A-4F, as long as the upper end region 31 forms an overhang with the contact surface 32, the overhang being arranged in the path of movement of the associated contact plate of the contact element such that the contact plate can move beyond the connection region 37 of the auxiliary contact 3 and contact the contact surface 32 after traveling the contact path KW. For example, the contact surface 32 can be formed horizontally as shown in FIG. 5A, so that the connection region 37 together with the upper end region 31 have a T-shaped cross section in a vertical cross section of the auxiliary contact 3. Furthermore, the contact surface 32 can also have a round cross section in a vertical cross section of the auxiliary contact 3, for example, formed as a portion of a sphere, as shown in FIG. 5B.

[0101] The auxiliary contacts 3 and the contact element 4 of the embodiment described in connection with Figures 4A-4F must be assembled in the switching device 100 in the correct position relative to each other so that the contact plate 42 is in the correct position relative to the auxiliary contacts 3 and can contact them in the second switching state of the switching device 100. In connection with Figures 6A-6C, a further embodiment of the switching device 100 is shown, which has a contact element 4 for which positional accuracy does not need to be taken into account, as compared to the embodiment of Figures 4A-4F. The views of Figures 6A and 6B correspond to the views of the switching device 100 shown in Figures 4C and 4D, and Figure 6C shows the contact element 4. The following description is again limited to the differences from the previous description. Features not described may preferably be formed as described above.

[0102] The contact element 4 shown in Figures 6A to 6C has a plurality of connecting webs 41 that are separated by slits 44 and arranged circumferentially on a contact ring 43, extending away from the contact ring 43. A contact plate 42 is arranged adjacent to each of the connecting webs 41. Furthermore, the connecting webs 41 are arranged on the inner edge of the contact ring 43, in comparison to the contact element 4 of the embodiment described in connection with Figures 4A to 4F, in which the connecting webs 41 are arranged on the outer edge of the contact ring 43. However, alternatively, other arrangements are also possible in both embodiments.

[0103] Each connecting element 41, on which the contact plates 42 are arranged, is spring-shaped as described above, so that the above-described functionality of the contact elements 4 is also ensured in this case. The slits 44 have a width smaller than the width of the contact area of ​​the auxiliary contact, so that in any rotation of the contact elements 4 about the vertical axis 91, i.e., about the axis 7, one or two adjacent contact plates 42 can always contact the auxiliary contact 3 in the second switching state of the switching device 100. Thus, a substantially continuous, but nevertheless spring-shaped, contact surface can be formed on the contact elements 4 by the circumferentially formed contact plates 42 separated only by the slits 44. The contact plates 42 can have a curved shape as shown, or alternatively, can be formed as described in connection with FIGS. 4A-4F.

[0104] The features and embodiments described in connection with the drawings can be combined with each other according to further embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in connection with the drawings can alternatively or additionally have further features according to the description in general part.

[0105] The present invention is not limited by the description based on the examples, but rather includes all novel features and all combinations of features, including all combinations of features in the claims, even if the feature or combination itself is not explicitly set out in the claims or examples. [Explanation of symbols]

[0106] 1 Fixed contact 2 movable contacts 3 Auxiliary Contacts 4 Contact Elements 5 Magnet Armature 6 magnetic core 7 axes 8 coils 9 York 10 Return spring 11 Switching Chamber 12 Switching chamber cover 13 Bottom of switching chamber 14 Interior Space 15 flange 18 Gas filling nozzle 19 Housing 20 Airtight Zone 21 Wall area 22 Wall area 28 Upper area 29 Lower area 30 ceramic elements 31 Upper end 32 Contact area 33 Lower end 34 Connection Area 35 flange 36 Fixed area 37 Connection Area 39 Aperture 40 Contact Web 41 Connected Web 42 Contact Plate 60 recess 43 Contact Ring 44 Slit 70 Contact spring 71 Contact holder 91 vertical direction 92 Longitudinal 93 Transverse 100 Switching Device A. Distance B Width MS magnetic gap Magnetic gap in MSK switching sticking KW contact route SW switching path

Claims

1. A switching device (100) comprising: - at least one fixed contact (1) and one movable contact (2) in a switching chamber (11); - a contact element (4) outside the switching chamber; a mechanical drive with a shaft (7) intended and adapted to move said movable contact and said contact element; - at least two auxiliary contacts outside the switching chamber on the opposite side of the axis from the movable contact; and the contact element contacts the at least two auxiliary contacts in a first switching state of the switching device and is separated from the at least two auxiliary contacts in a second switching state of the switching device, or is separated from the at least two auxiliary contacts in the first switching state of the switching device and contacts the at least two auxiliary contacts in the second switching state of the switching device; In the first switching state of the switching device, the movable contact is separated from the at least one fixed contact, and in the second switching state of the switching device, the movable contact is in contact with the at least one fixed contact; The switching device further has at least one of the following features [1] to [6]. [1] The contact element comprises a contact web (40) or a contact ring (43), at least two connecting webs (41) extending away from the contact web or the contact ring, and a contact plate (42) in contact with each of the connecting webs, the contact plates facing each other. [2] The contact element is spaced from the at least two auxiliary contacts in the first switching state of the switching device, and contacts the at least two auxiliary contacts in the second switching state of the switching device, and at least a portion of the contact element is arranged laterally adjacent to the at least two auxiliary contacts in the first switching state of the switching device. [3] The contact element has a contact ring and a plurality of connecting webs separated by gaps and arranged circumferentially on the contact ring and extending away from the contact ring, with a contact plate arranged on each of the connecting webs. [4] The contact element has a contact ring (43), connecting webs (41) extending away from the contact ring, and contact plates (42) contacting each of the connecting webs, the contact element being spaced apart from the at least two auxiliary contacts in the first switching state of the switching device and contacting the at least two auxiliary contacts in the second switching state of the switching device, each of the at least two auxiliary contacts having an upper end pointing towards the axis, and the contact plates of the contact element being arranged below the upper end point as viewed from the axis, regardless of the switching state of the switching device. [5] The contact element has a contact ring (43), connecting webs (41) extending away from the contact ring, and contact plates (42) in contact with each of the connecting webs, the contact element being spaced apart from the at least two auxiliary contacts in the first switching state of the switching device and contacting the at least two auxiliary contacts in the second switching state of the switching device, each of the at least two auxiliary contacts having a contact area facing away from the axis, each of the contact areas being mechanically contacted by a contact plate in the second switching state of the switching device, and each of the contact areas being arranged between the contact ring and the contact plate in mechanical contact with the contact area, at least in the second switching state of the switching device. [6] The contact element is spaced from the at least two auxiliary contacts in the first switching state of the switching device and contacts the at least two auxiliary contacts in the second switching state of the switching device, each of the at least two auxiliary contacts having a contact area facing away from the axis, each of the contact areas being mechanically contacted by a contact plate in the second switching state of the switching device, and each of the contact areas being formed in the form of a conical surface.

2. 2. The switching device of claim 1, wherein the contact element is at least partially spring-shaped.

3. 3. A switching device according to claim 1, wherein the contact elements are integrally formed.

4. 3. The switching device according to claim 1, wherein the contact element is arranged in a hermetic area (20), and the at least two auxiliary contacts are arranged partly in the hermetic area and partly outside the hermetic area.

5. 5. The switching device according to claim 4, wherein the at least two auxiliary contacts protrude through openings (39) in a ceramic element (30), the ceramic element forming part of a wall of the gas-tight region.

6. 6. The switching device of claim 5, wherein the ceramic element is connected with a wall region (22) comprising stainless steel, the ceramic element and the wall region together forming a cup shape.

7. - the contact element is arranged on an element of the mechanical drive that causes a switching movement of the movable contact; - the mechanical drive comprises a magnet armature (5) comprising the shaft and a magnetic core (6), the contact element being directly fixed to the magnetic core; - the contact elements or the contact rings are welded to the magnetic core; 3. A switching device according to claim 1 or 2.

8. 8. The switching device of claim 7, wherein the magnetic core has a recess (60) in which a portion of the contact element is located.

9. The contact element is separated from the at least two auxiliary contacts in the first switching state of the switching device and contacts the at least two auxiliary contacts in the second switching state of the switching device; 3. The switching device according to claim 1, wherein the mechanical drive travels a path MS during the transition from the first switching state to the second switching state, and the contact element mechanically contacts the at least two auxiliary contacts after a contact path KW, where KW<MS.

10. 3. The switching device according to claim 1, wherein the movable contact travels a switching path SW during the transition from the first switching state to the second switching state, and the contact element loses mechanical contact with the at least two auxiliary contacts after a contact path KW that satisfies KW / SW≦0.

2.

11. 3. A switching device according to claim 1, wherein the contact plates are opposed to each other and have a distance A from each other that is smaller than the width B of the auxiliary contact.

12. 3. The switching device according to claim 1, wherein the mechanical drive comprises a return spring (10) having a return spring force RFK, and the contact elements have a spring force FK such that FK / RFK≦0.2.

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