Switching device

Abstract

The present invention provides a switching device (100) having at least one fixed contact (2) protruding into a switching chamber (11). [Solution] A switching device wherein at least one fixed contact has a fixed portion and a connecting portion, the fixed portion is fixed to a switching chamber, the connecting portion protrudes into a recess of the fixed portion, the connecting portion and the fixed portion are manufactured from the same material, the contact contains copper or a copper alloy, and the fixed portion has lower hardness than the connecting portion.

Description

Technical Field

[0001] A switching device is presented.

Background Art

[0002] The switching device is designed as a remotely operated switch that can be driven by an electric current and operates electromagnetically. 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, especially as a power contactor. Particularly preferably, the switching device can be designed as a gas-filled power contactor.

[0003] One possible use of such a switching device, especially a power contactor, is the opening and disconnection of the battery circuit in a motor vehicle, such as a motor vehicle with an electrically or partly electrically driven motor. These can be, for example, purely battery-driven vehicles (BEV: "battery electric vehicle"), plug-in hybrid electric vehicles (PHEV: "plug-in hybrid electric vehicle") and hybrid electric vehicles (HEV: hybrid electric vehicle) that can be charged via a power socket or a charging station. In this case, usually, the positive and negative contacts of the battery are both disconnected using a power contactor. This disconnection is carried out, for example, during normal operation, such as the idling state of the vehicle, or in case of a fault, such as an accident. At this time, switching the vehicle to zero potential and interrupting the current are the main roles of the power contactor.

[0004] The contactor usually carries a large current during operation. The current is usually carried via a power supply line, such as a copper wire, a so-called busbar, or other power supply lines, and they are attached to the externally accessible contacts of the contactor, which can also be referred to as pole contacts or terminals. The copper wire or other power supply lines are 200 mm 2It may have a cross-sectional area exceeding [a certain value]. To ensure sufficient, i.e., low-resistance electrical contact, the feed lines must be tightened with a sufficiently high torque, which imposes high mechanical requirements on the contactor's polar contacts. In addition, shear and lever forces can occur at the contact points during installation and subsequent operation. Therefore, the contact points should be manufactured from a particularly hard but highly conductive material.

[0005] High-performance contactors often have a switching chamber made of ceramic material, and the contacts are soldered within this switching chamber using hard solder at temperatures exceeding 800°C. However, this process carries the risk of altering the material properties of most highly conductive materials that can be used for the contacts, causing the material to become softer. In such cases, adequate securing of the power supply line becomes impossible without problems.

[0006] To circumvent this problem, a material that remains sufficiently hard to withstand stress after the soldering process may be used. However, this usually results in an increase in the cost of the base material used, for example, because a special copper alloy must be used. Furthermore, it is also known to integrate a busbar piece into the contactor, which may allow for an additional spatially moved fixed point. However, this has the disadvantage of leading to higher costs due to the additional components, a larger final weight of the contactor, and increased electrical contact resistance from fixed point to fixed point.

[0007] Patent documents 1, 2, 3, 4, and 5 describe switching devices. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2005-038706 [Patent Document 2] Japanese Patent Application Publication No. 11-232986 [Patent Document 3] U.S. Patent Application Publication No. 2008 / 0122562 [Patent Document 4] U.S. Patent Application Publication No. 2016 / 0012995 [Patent Document 5] German Patent No. 102019129805 Specification [Overview of the project] [Problems that the invention aims to solve]

[0009] At least one objective of a particular embodiment is to present a switching device. [Means for solving the problem]

[0010] This problem is solved by the subject matter in the independent claim. Advantageous embodiments and developments of the subject matter are described in the dependent claims and will become clear from the following description and drawings.

[0011] According to at least one embodiment, the switching device has at least one fixed contact. The at least one fixed contact may be intended and adapted in particular to connect a power supply line of a load circuit that is to be switched on, i.e., closed, and switched off, i.e., disconnected, by the switching device.

[0012] Furthermore, the switching device may have at least one movable contact. The movable contact may, in particular, comprise or be a contact bridge. In other words, the contact bridge may be a movable contact of the switching device or part of a movable contact of the switching device. Therefore, the characteristics and features of the movable contact described below may be the corresponding characteristics and features of the contact bridge, and vice versa.

[0013] At least one fixed contact and at least one movable contact are intended and adapted to switch the on and off of a load circuit that can be connected to the switching device. Accordingly, the movable contact, i.e., the contact bridge in particular, is movable within the switching device between the disconnected state and the connected state such that, in the disconnected state of the switching device, it is separated from and therefore electrically disconnected from at least one fixed contact, and in the connected state, it has mechanical contact with at least one fixed contact and is therefore electrically connected to that at least one fixed contact. Hereinafter, the connected state will also be referred to as the switched-on state of the switching device, and the disconnected state will also be referred to as the switched-off state of the switching device.

[0014] Particularly advantageous is that the switching device has at least two fixed contacts, which are arranged separately from each other within the switching device and, in the manner described above, can be electrically connected to or electrically separated from each other via the movable contacts, i.e., particularly the contact bridge, depending on the state of the movable contacts, i.e., the contact bridge. The contact bridge preferably has an upper surface having at least one contact area and a lower surface opposite to the upper surface. In the connected state of the switching device, at least one contact area of ​​the contact bridge is in mechanical contact with at least one fixed contact, in particular the contact area of ​​at least one fixed contact. If the switching device has, for example, two fixed contacts, the contact bridge may have two corresponding contact areas. The features described below for one fixed contact may apply to multiple fixed contacts of the switching device, in particular preferably each fixed contact.

[0015] In the following, the general term “contact” may be associated in particular with all fixed contacts and contact bridges. In particular, contacts may contain or consist of a metal, preferably copper or a copper alloy. Furthermore, composite materials in the form of a metal matrix material are also possible, for at least the contact area, preferably containing or consisting of copper, and in which particles of a ceramic material, such as aluminum oxide, are dispersed.

[0016] In a further embodiment, the switching device has a housing in which a movable contact and at least one fixed contact or at least two fixed contacts are arranged. The movable contact may, in particular, be entirely housed within the housing. The fact that the fixed contact is housed within the housing may, in particular, mean that at least the contact area of ​​the fixed contact that mechanically contacts the movable contact in a connected state is housed inside the housing. For the connection of the wires of the circuit to be switched by the switching device, the fixed contact housed within the housing may be electrically accessible from the outside, i.e., from outside the housing. For this purpose, a portion of the fixed contact housed within the housing may protrude from the housing and have the possibility of connection for power lines outside the housing.

[0017] In a further embodiment, the contacts are located in a gaseous atmosphere within the housing. This may mean, in particular, that the movable contacts are located entirely in a gaseous atmosphere within the housing, and furthermore, that a portion of the fixed contacts, for example, the contact area of ​​the fixed contacts, is located in a gaseous atmosphere within the housing. Accordingly, the switching device may be a gas-filled switching device, such as a gas-filled contactor, in particular.

[0018] In a further embodiment, the switching device has a switching chamber. The switching chamber may be located inside a housing, in particular. In particular, the switching chamber has an internal space. The contacts, i.e., the entire movable contact and a portion of at least one fixed contact, are located within the internal space of the switching chamber. Thus, at least one fixed contact protrudes into the switching chamber. At least one fixed contact protrudes into the internal space of the switching chamber, in particular through an opening. In other words, at least one fixed contact is located partially inside the switching chamber and partially outside the switching chamber. For example, the switching chamber may have a switching chamber bottom. The switching chamber may further have a switching chamber cover that may surround the internal space together with the switching chamber bottom. In at least the region in which at least one fixed contact protrudes into the switching chamber, the switching chamber contains or consists of a ceramic material, such as aluminum oxide. For example, at least one fixed contact may protrude through an opening in the switching chamber cover. In this case, the switching chamber cover is preferably made of a ceramic material.

[0019] A gas, i.e., at least a portion of the aforementioned gas atmosphere, may be present inside the switching chamber. The gas may preferably contain at least 20% H2, preferably 50% H2. In addition to hydrogen, the gas may contain an inert gas, particularly preferably N2 and / or one or more noble gases.

[0020] According to a further embodiment, the movable contact is movable within the switching device by means of a shaft. In particular, the movable contact can be movable, for example, by means of a drive device having a shaft, and the drive device can be formed in the form of a magnetic drive device comprising a magnet armature or in the form of a motor drive device. The shaft is coupled at one end to the movable contact such that the movable contact is movable by the shaft, i.e., is similarly moved by the shaft upon movement of the shaft. The shaft can protrude, in particular, through an opening of the switching chamber into the interior space of the switching chamber. In the case of a magnetic drive device, the magnet armature can be movable by means of a magnetic circuit in order to cause the switching operation described above. For this purpose, the magnetic circuit can have a yoke having an opening through which the shaft of the magnet armature protrudes. The shaft can preferably comprise or consist of special steel. The yoke can preferably comprise or consist of pure iron or a low-doped iron alloy.

[0021] According to a further embodiment, at least one fixed contact has, when joined, two parts that substantially form at least one fixed contact. In the switching device, the two parts are permanently joined. Particularly preferably, the two parts are joined permanently, and thus cannot be separated from one another under normal operating conditions. Furthermore, at least one fixed contact can have one or more bonding materials that improve the permanent joining of the two parts.

[0022] In particular, at least one fixed contact has, as two parts, a fixing part and a connecting part, which, when joined, substantially form at least one fixed contact, for example excluding at least one bonding material. Particularly preferably, the connecting part and the fixing part are joined to one another, for example by a clamp connection or particularly preferably by a screw connection, at least by engagement and / or by frictional force. Furthermore, the connecting part and the fixing part can also be joined to one another additionally by intermolecular force bonding.

[0023] The fixing part is intended and adapted to be fixed to the switching chamber such that at least one fixed contact is fixed to the switching chamber by the fixing part. In particular, the fixing part can be coupled to the switching chamber by bonding by intermolecular forces. The connecting part is intended and adapted to be connected to an external power supply line, so that as a result, at least one fixed contact can be connected to the external power supply line by the connecting part.

[0024] According to a further embodiment, the fixing part has a recess, and the connecting part projects into the recess of the fixing part. The recess can in particular preferably be formed as a blind hole, so that as a result, the connecting part does not project through the fixing part. In particular, the fixing part can be formed in a cup shape. The fixing part can have a contact surface in the bottom region opposite to the connecting part, and by means of this contact surface, the fixing part, and thus at least one fixed contact, mechanically contacts the movable contact in the switched-on state of the switching device. Thus, the contact surface is arranged within the switching chamber. Thus, the above-described internal mechanical contact with the fixed contact is preferably effected via the fixing part, while the external mechanical contact with the external power supply line is effected via the connecting part.

[0025] According to a further embodiment, the connecting part is accessible outside the switching device. In particular, the connecting part can have a connecting element arranged outside the housing of the switching device. The connecting element can be formed, for example, by a stud bolt. Particularly preferably, the stud bolt has a male thread. Alternatively, the connecting element can be, for example, a threaded hole in or of the connecting part.

[0026] Furthermore, the connecting part can have a support element that extends away from the connecting element. In particular, the connecting element can extend away in a direction away from the fixing part as seen from the support element. For this purpose, the support element can in particular preferably have an upper surface opposite to the switching chamber, from which the connecting element projects.

[0027] The support element can be formed, for example, in the form of a disc, particularly preferably a circular disc, from which a connecting element, for example, in the form of a stud bolt, protrudes from the center. The connecting element may be provided for positioning and placement, and for securing an external power supply line. If the connecting element has a male thread, a fixing nut, for example, can be screwed into the connecting element. The upper surface of the support element can form a support surface for the external power supply line, and in order to achieve the lowest possible electrical contact resistance between at least one fixed contact and the first power supply line, the external power supply line is pressed against the support surface when it is fixed, i.e., when the fixing nut is tightened. Thus, the external power supply line may have, for example, a hole through which the connecting element protrudes, and may be clamped between the fixing nut screwed into the connecting element and the support element.

[0028] In a further embodiment, the connection portion has a coupling element. The coupling element is preferably located on the support element opposite to the connection portion. The coupling element may be formed, for example, by a stud bolt. In particular, the coupling element may extend in a direction toward the fixed portion when viewed from the support element. For this purpose, the support element may particularly preferably have a lower surface facing toward the switching chamber from which the coupling element protrudes.

[0029] In particular, the coupling element can protrude into the recess of the fixing part, and is especially preferably located within the recess. The connecting part can be screwed into the recess together with the coupling element, especially preferably. For this purpose, the coupling element may have a male thread, and the recess of the fixing part may have a female thread. Especially preferably, the connecting element and the coupling element may each have a male thread of the same thread size.

[0030] In further embodiments, the male threads of the coupling element and / or the female threads of the recess have an interlocking fit before the connector is screwed into the fixing part. In other words, the female threads of the recess are permitted to be smaller than the male threads of the coupling element. The threads preferably correspond to the standards of DIN 13-1 to DIN 13-52, particularly preferably DIN 13-51 (intermediate tolerance zone for airtight fits). For example, an "M8-5H / 4h" fit (intermediate fit) may exist. The standards of DIN 13 generally refer to fine threads, such as M6, M8, etc. Furthermore, non-metric thread types, such as those according to ASME B1.1, and special threads, such as those according to DIN 7756 and valve threads, are also included. By screwing the coupling element into the recess, a stronger threaded connection can be achieved due to the oversized inner diameter, thereby preventing the connector from unintentionally detaching from the fixing part (due to loosening of the threads).

[0031] In a further embodiment, a bonding material is placed between the male thread of the bonding element and the female thread of the recess. The bonding material may include, for example, methacrylic resin or an acrylate such as cyanoacrylate, or an adhesive made therefrom, or it may be an adhesive.

[0032] In a further embodiment, the bonding material is located below the connecting element within a recess. The recess, for this purpose, is particularly preferably deeper than the height of the connecting element as measured from the lower surface of the support element, so that when the connection is fully screwed into the fixing part, a cavity remains below the connecting element in which the bonding material can be placed. The bonding material may include or consist of an adhesive, such as the adhesive described above, or a soft solder. Hereinafter, a solder having a melting point of preferably 400°C or less is referred to as soft solder. The soft solder may, for example, be placed in the form of a solder pill within a recess of the fixing part already fixed to the switching chamber. After the connection is screwed in, the soft solder can be melted, for example, by heating in a furnace. The soft solder does not necessarily contain flux. Alternatively, the soft solder may be provided with flux. The flux may, for example, improve the wettability of the soft solder. The soft solder may preferably be lead-free. For example, soft solder may contain or consist of one or more materials selected from bismuth (Bi), tin (Sn), and antimony (Sb). The proportions based on mass may be, for example, 25% to 35%, particularly preferably 27% to 31%, for bismuth and tin, and 50% to 70%, particularly preferably 38% to 46%, for antimony. Furthermore, soft solder may contain or consist of one or more materials selected from, for example, tin (Sn), silver (Ag), and copper (Cu). The proportions based on mass may be, for example, 50% or more, particularly preferably 85% or more, for tin. The proportion based on mass of silver may be less than 15%, preferably less than 5%. The proportion based on mass of copper may be less than 5%, preferably less than 1%. For example, soft solder may be Sn96.5Ag3.0Cu0.5.

[0033] In a further embodiment, the support element rests on the fixing portion on its lower surface. The fixing portion may have an edge region with an upper surface on which the lower surface of the support element rests. The edge region may be formed to surround a recess of the fixing portion, particularly preferably.

[0034] In a further embodiment, a bonding material is placed between the lower surface of the support element and the upper surface of the edge region. For example, the bonding material includes or may include soft solder, such as the soft solder described above.

[0035] In a further embodiment, the upper surface of the edge region of the fixed portion and / or the lower surface of the support element of the connecting portion have a surface structure, such as knurling and / or surface roughening. The surface structure may be provided in relation to the bonding material between the lower surface of the support element and the upper surface of the edge region, particularly preferably.

[0036] In a further embodiment, the support element is welded to the edge region. In particular, the support elements can be joined to each other in the edge region by a welded joint outside the contact area formed by the lower surface of the support element and the upper surface of the edge region, and the welded joint may, particularly preferably, completely encircle the edge.

[0037] One or more of the aforementioned bonding materials and / or surface structures and / or welds can improve the fastening of the connection to the fastener. This can reduce or even prevent the risk of the connection unintentionally loosening from the fastener.

[0038] The support element and the edge region may, particularly preferably, have the same outer diameter. The upper surface of the edge region and the lower surface of the support element may both be formed in a ring shape and positioned coincidentally on top of each other. Furthermore, the support element and the edge region may each be partially positioned within the opening of the housing of the switching device. In particular, the contact area between them, i.e., the upper surface of the edge region and the lower surface of the support element, may be positioned inside the opening of the housing.

[0039] In a further embodiment, the edge region has a fixed edge facing the switching chamber, which is bonded to the switching chamber by intermolecular forces. In other words, the fixed edge is located on the side opposite to the top surface. In particular, the fixed edge can be bonded to the switching chamber by hard solder, thereby fixing at least one fixed contact to the switching chamber. The switching chamber may have a corresponding edge region through which at least one fixed contact, i.e., the fixed portion, protrudes into the switching chamber, surrounding an opening, which may be formed, for example, by a raised ring structure, and the fixed edge is fixed on this edge region by hard soldering. Hereinafter, solder having a melting point of 600°C or higher is referred to as hard solder. As hard solder, for example, a silver and / or copper-based solder, particularly preferably a silver-copper alloy such as Ag72Cu28, may be used.

[0040] In further embodiments, the connector and the fixed part are manufactured from the same material. In particular, the connector and the fixed part may each contain or consist of the materials generally described above for contacts, such as metal, preferably copper or a copper alloy. In the installed state, i.e., when at least one fixed contact is fixed to the switching chamber, the fixed part may have lower hardness than the connector. This can be achieved by soldering the fixed part to the switching chamber with hard solder. Due to the typical high temperature during hard soldering, for example, above 800°C, the material of the fixed part may become softer after hard soldering due to a solid-phase physical process. In contrast, the connector can maintain its original hardness because it does not undergo a hard soldering process and is screwed in after hard soldering.

[0041] Accordingly, in the switching device described herein, one or more fixed contacts forming fixed points for external power lines are designed to consist of two parts, with each part, preferably a small part, of the fixed contact actually soldered with hard solder, and a second part that does not undergo the soldering process being added later. This has the advantage of not having the weight disadvantage compared to a normal one-part contact, preferably with no or only slight increase in contact resistance due to the same material, and nevertheless achieving increased mechanical strength compared to a one-part fixed contact. With the measures described above, the second part can be securely fixed to the soldered first part. Thereafter, the fixed contact and the switching device described herein can be manufactured inexpensively with little or no increase in process cost, and can withstand higher mechanical loads compared to a one-part fixed contact.

[0042] Further advantages, favorable embodiments, and developmental forms will become apparent from the embodiments described below in conjunction with the drawings. [Brief explanation of the drawing]

[0043] [Figure 1A] This is a schematic diagram of an example of a switching device. [Figure 1B] This is a schematic diagram of an example of a switching device. [Figure 2A] This is a schematic diagram of the fixed contacts of a switching device. [Figure 2B] This is a schematic diagram of the fixed contacts of a switching device. [Figure 2C] This is a schematic diagram of the fixed contacts of a switching device. [Figure 2D] This is a schematic diagram of the fixed contacts of a switching device. [Figure 2E] This is a schematic diagram of the fixed contacts of a switching device. [Figure 3A] This is a schematic diagram of a method for attaching fixed contacts to the switching chamber cover of a switching device according to a further embodiment. [Figure 3B]This is a schematic diagram of a method for attaching fixed contacts to the switching chamber cover of a switching device according to a further embodiment. [Figure 4] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 5] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 6] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 7A] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 7B] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 8A] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Figure 8B] This is a schematic diagram of a fixed contact of a switching device according to a further embodiment. [Modes for carrying out the invention]

[0044] In the examples and drawings, identical, similar, or equivalently functioning elements may be given the same reference numeral. The illustrated elements and their relative sizes are not to scale; rather, individual elements such as layers, parts, components, and regions may be exaggerated in size for better illustration and / or better understanding.

[0045] Figures 1A and 1B show embodiments of a switching device 100, which can be used, for example, to switch high currents and / or high voltages, and may be a relay or a contactor, particularly a power contactor. Figure 1A shows a three-dimensional cross-sectional view with a vertical cross-section. Figure 1B shows an enlarged view of section BB shown in Figure 1A. The illustrated geometric shapes should be understood to be illustrative and not limiting, and may be designed in other embodiments.

[0046] The switching device 100 has contacts 2 and 4 within a housing 1, which are also referred to below as switching contacts. The housing 1 is used primarily as contact protection for components located inside and contains or consists of plastic, such as PBT or glass fiber-reinforced PBT. In the illustrated example, the switching device 100 has, as contacts, two fixed contacts 2 and a movable contact in the form of a contact bridge 4 supported on an insulator 3. The contact bridge 4 is designed as a contact plate. The fixed contacts 2, together with the contact bridge 4, form the switching contacts. In place of the illustrated number of contacts, other numbers of contacts, i.e., other numbers of fixed and / or movable contacts, are also possible. The fixed contacts 2 and / or the contact bridge 4 may contain or consist of, for example, Cu, a Cu alloy, or a mixture of, for example, copper and at least one other metal such as, for example, Wo, Ni and / or Cr.

[0047] In Figure 1A, the switching device 100 is shown in the switched-off state, with the contact bridge 4 separated from the fixed contacts 2, and as a result, the contacts 2 and 4 are electrically disconnected from each other. To transition the switching device 100 to the switched-on state, the illustrated contact bridge 4 must be moved upward in the direction of the fixed contacts 2 until the contact bridge 4 makes mechanical contact with the fixed contacts 2. In the illustrated embodiment, the switching device 100 has a magnetic drive unit comprising a movable magnetic armature 5 that substantially performs the switching operation. The magnetic armature 5 has a magnetic core 6 which contains or is made of, for example, a ferromagnetic material. Furthermore, the magnetic armature 5 has a shaft 7 which is guided through the magnetic core 6 and is firmly coupled to the magnetic core 6 at one shaft end. At the other shaft end opposite to the magnetic core 6, the magnetic armature 5 has the contact bridge 4. The shaft 7 may preferably contain or be made of special steel.

[0048] To electrically isolate the contact bridge 4 from the shaft 7, an insulator 3, which may also be called a bridge insulator, is placed between them. To help compensate for possible height differences and to ensure sufficient mechanical contact between the fixed contact 2 and the contact bridge 4, a contact spring 34 is placed below the contact bridge 4, supported by the insulator 3 and exerting force on the contact bridge 4 in the direction of the fixed contact 2.

[0049] The magnetic core 6 is surrounded by a coil 8. A current in the coil 8, which can be connected externally via a control circuit, generates axial motion of the magnetic core 6, and thus the entire magnet armature 5, until the contact bridge 4 contacts the fixed contact 2. In the illustrated example, the magnet armature 5 moves upward for this purpose. Thus, the magnet armature 5 moves from a first position, i.e., the idle position, which corresponds to a disconnected state, or unconnected state, and therefore the switched-off state, to a second position, i.e., the active state, or connected state, and therefore the switched-on state. In the active state, the switching contacts are electrically connected to each other.

[0050] To guide the shaft 7 and, consequently, the magnet armature 5, the switching device 100 has a yoke 9, which may contain or consist of pure iron or a low-doped iron alloy, and forms part of the magnetic circuit. The yoke 9 has an opening through which the shaft 7 is guided. Furthermore, a guide sleeve (not shown) may be provided within the opening of the yoke 9. When the current in the coil 8 is interrupted, the magnet armature 5 is moved back to the first position by one or more springs 10. Thus, in the illustrated example, the magnet armature 5 moves downward again. The switching device 100 is then back in an idle state with its contacts open.

[0051] For example, when a switching contact is opened, at least one arc may be generated that could damage the contact surface of the switching contact. This could create a risk that the switching contacts may become "stuck" to each other due to welding caused by the arc and can no longer be separated from each other. In this case, the switching device 100 remains switched on, even though the current in the coil 8 should be switched off and therefore the load circuit should be disconnected. To prevent such arc generation, or at least to facilitate the extinguishing of any arcs that do occur, the switching contacts can be placed in a gas atmosphere, and as a result, the switching device 100 can be designed as a gas-filled relay or gas-filled contactor. In particular, for example, the switching contacts inside the switching chamber 11, formed by the switching chamber cover 12 and the switching chamber bottom 13, are located within an airtight region 14 formed by an airtightly closed portion, and the switching chamber 11 may be part of the airtight region 14. The airtight region 14 completely surrounds the magnet armature 5 and the switching contacts, except for the portion of the fixed contacts 2 provided for external connection. The airtight region 14, and therefore the internal space 15 of the switching chamber 11, is also filled with gas. The airtight region 14 is substantially formed by the switching chamber 11, the yoke 9, and part of an additional wall. The gas that can be filled into the airtight region 14 through the gas filling nozzle 17 within the framework of the manufacture of the switching device 100 is, particularly preferably, a hydrogen-containing gas, for example, an inert gas containing 20% ​​or more H2, or 100% H2, because a hydrogen-containing gas can promote arc extinguishing. Furthermore, a so-called blowout magnet, i.e., a permanent magnet 16 that can result in an extension of the arc path and thus improve arc extinguishing, can be present inside or outside the switching chamber 11.

[0052] The switching chamber cover 12 and the switching chamber bottom 13 may be made of or manufactured from a ceramic material such as a metal oxide such as Al2O3. Furthermore, for example, the switching chamber bottom 13 may also be made of a plastic with sufficiently high temperature stability, such as PEEK, PE and / or glass fiber-filled PBT. Alternatively or additionally, the switching chamber 11 may be made of at least part of, in particular, a (CH2O) structure. n This may also include POM having (CH2O). Such plastics may be characterized by a relatively low carbon content and a very small graphite formation tendency. n In this case, because the carbon and oxygen content are the same, gaseous CO and H2 may be generated mainly during decomposition induced by heat, especially by arc. Additional hydrogen can enhance arc extinguishing. Particularly preferably, the switching chamber cover 12 is made of a ceramic material, and the switching chamber bottom 13 is made of a ceramic material or plastic as described above.

[0053] The fixed contact 2 is positioned within the opening 121 of the switching chamber cover 12 and protrudes through the opening 121 into the internal space 15 of the switching chamber 11, so that, in particular, the contact surface 208 of the fixed contact 2 is positioned within the internal space 15 of the switching chamber 11. The fixed contact 2 is permanently and particularly hermetically attached to the mounting region 122 of the switching chamber cover 12 extending around the opening 121 by intermolecular force bonding. Particularly preferably, the fixed contact 2 is attached to the switching chamber 11 by hard soldering. For this purpose, the fixed contact 2 having a fixed portion 20 and a connecting portion 21 has an edge region 203 with a fixed edge portion 205, and hard solder (not shown) is placed between the edge region 203 and the mounting region 122. As the hard solder, for example, a silver and / or copper-based solder, particularly preferably a silver-copper alloy such as Ag72Cu28, may be used. The method steps for attaching the fixed contact 2 to the switching chamber cover 12 will be described with reference to Figures 3A and 3B.

[0054] To connect the fixed contact 2 to an external power supply line (not shown) of the load circuit, the fixed contact 2 has a connecting element 211 formed as a so-called stud bolt that protrudes through the opening 101 of the housing 1, as shown in Figures 1A and 1B, and to which the external power supply line, such as a supply rail, so-called busbar, or cable lug, is attached, for example, a supply rail. The connecting element 211 may have threads, as will be described in relation to the following drawings, and as a result, the external power supply line may be fixed to the connecting element 211 and thus to the fixed contact 2, and pressed against the support element 213, for example, using a nut. A sufficiently large tightening torque is required to screw the nut into the connecting element 211 in order to achieve the lowest possible electrical contact resistance between the external power supply line and the fixed contact 2 and to ensure a permanent mechanical connection even in the case of shear and lever forces that may occur during operation. Therefore, the connecting element 211 in particular must have sufficient mechanical strength. In other words, the material of the connecting element 211 must be sufficiently hard. However, as explained earlier, in the case of conventional fixed contacts, the hard soldering process used to secure the fixed contacts will result in material changes, particularly softening.

[0055] Therefore, in the illustrated switching device 100, the fixed contact 2 is formed as consisting of two parts. Further features and embodiments of the fixed contact 2 will be described in reference to the following drawings.

[0056] Figures 2A to 2E show various views of the fixed contacts 2 corresponding to the two fixed contacts 2 of the switching device 100 according to the embodiment in Figures 1A and 1B. In other words, the fixed contacts 2 of the switching device 100 can be formed as described in Figures 2A to 2E. Figures 2A and 2B show a three-dimensional plan view and a three-dimensional cross-sectional view of the fixed contacts 2. Figures 2C to 2E show further various cross-sectional views of the fixed contacts 2 or a part thereof. The following description is similarly related to Figures 2A to 2E.

[0057] As described in relation to Figures 1A and 1B, the fixed contact 2 has two parts formed by a fixed portion 20 and a connecting portion 21, which, when coupled, substantially form at least one fixed contact 2 and are permanently coupled in the switching device. Particularly preferably, the connecting portion 21 and the fixed portion 20 are coupled to each other, for example by clamp coupling, or particularly preferably by screw coupling, at least by engagement and / or friction. Furthermore, the connecting portion 21 and the fixed portion 20 may also be coupled to each other by intermolecular force bonding, as described in relation to Figures 4-8B.

[0058] The fixing portion 20 is intended and adapted to be fixed to the switching chamber by hard soldering, as described in relation to Figures 1A and 1B, and as a result, the fixed contact 2 is fixed to the switching chamber by the fixing portion 20. The connection portion 21 is intended and adapted to be connected to an external power supply line, as described in relation to Figures 1A and 1B, and as a result, the fixed contact 2 can be connected to an external power supply line by the connection portion 21.

[0059] The fixing portion 20 has a recess 200, and the connecting portion 21 protrudes into the recess 200 of the fixing portion 20. The recess 200 is formed as a blind hole, and as a result, the connecting portion 21 does not protrude through the fixing portion 20. In particular, the fixing portion 20 may be formed in a cup shape comprising a bottom region 201 and a wall region 202 connected thereto. The bottom region 201 is provided with a contact surface 28 on the side opposite to the connecting portion 21.

[0060] The connection portion 21 has a connecting element 211 designed as a stud bolt, which is located outside the housing of the switching device as shown in Figures 1A and 1B and has a male thread 212. The connecting element 211 extends from the upper surface 214 of the support element 213 away from the fixing portion 20. The support element 213 is formed particularly preferably in the form of a disk, especially preferably a circular disk, as can be seen in Figure 2A, for example, with the connecting element protruding from the center of the circular disk.

[0061] Furthermore, the connecting portion 21 has a coupling element 216. The coupling element 216 is positioned on the opposite side of the support element 213 from the connecting element 211 and is formed as a stud bolt protruding from the lower surface 215 of the support element 213 that faces the switching chamber. As a result, the coupling element 216 extends in the direction facing the fixed portion 20 when viewed from the support element 213.

[0062] The connecting element 216 protrudes into and is positioned within the recess 200 of the fixing part 20. The connecting part 21 is screwed into the recess 200 by the connecting element 216. For this purpose, the connecting element 216 has a male thread 217. The recess 200 of the fixing part 20 has a female thread 207 that fits into the wall region 202. For example, the connecting element 211 and the connecting element 216 may each have male threads 212 and 217 having the same thread size, for example, size M8. In particular, the male threads 212 and 217 may have the same direction of rotation, and therefore, for example, both may be right-hand threads.

[0063] Furthermore, the male thread 217 of the connecting element 216 and / or the female thread 207 of the recess 200 may, in general, have an interlocking fit as described above before screwing the connecting portion 21 into the fixing portion 20, thereby achieving a stronger screw connection, which can prevent the connecting portion 21 from unintentionally falling out of the fixing portion 20 (due to loosening of the screw).

[0064] After the connecting portion 21 is screwed in, the support element 213 is preferably positioned so that its lower surface 215 rests on the fixing portion 20. For this purpose, the fixing portion 20 may have an edge region 203, in particular, on which the lower surface 215 of the support element 211 rests, and as a result, the best possible electrical contact between the fixing portion 20 and the connecting portion 21 can be achieved. The edge region 203 may be formed to surround a recess 200 of the fixing portion 20, in particular.

[0065] The support element 211 and the edge region 203 may, in particular, have the same outer diameter.

[0066] The upper surface 204 of the edge region 203 and the lower surface 215 of the support element 211 may both be formed in a ring shape and positioned coincidentally on top of each other. As can be seen in Figures 1A and 1B, the support element 211 and the edge region 203 may each be positioned partially within the opening of the switching device housing. In particular, the contact areas between them, namely the upper surface 204 of the edge region 203 and the lower surface 215 of the support element 213, may be positioned inside the opening of the housing.

[0067] As described in relation to Figures 1A and 1B, the edge region 203 has a fixed edge 205 facing the switching chamber, which is bonded to the switching chamber by intermolecular forces. The fixed edge 205 may be separated from the wall region 202, for example, by a surrounding groove 204. Figures 3A and 3B show method steps of a method for attaching the fixed contacts 2 to the switching chamber cover 12, which can be performed for all fixed contacts 2 within the framework of manufacturing the switching device.

[0068] As shown in Figure 3A, the fixing portion 20 is inserted into the opening 121 of the switching chamber cover 12 such that the fixing edge portion 205 is positioned on the mounting area 122. The mounting area 122 may be formed, for example, by a raised ring structure in the edge region of the opening 121. Hard solder 120, such as silver and / or copper-based solder, particularly preferably a silver-copper alloy such as Ag72Cu28, is applied between the mounting area 122 and the fixing edge portion 205. The switching chamber cover 12, along with the fixing portions 20 of all the fixing contacts 2 thus positioned, is heated, for example, in a furnace, and an airtight bond is established between the switching chamber cover 12 and the fixing portions 20 via the hard solder 120, which melts and resolidifies as a result. Subsequently, as shown in Figure 3B, the connecting portion 21 may be screwed into each fixing portion 20.

[0069] Particularly preferably, the connector 21 and the fixing part 20 are manufactured from the same material, for example, a metal, preferably oxygen-free copper or a copper alloy, or composed of the same. In the installed state, i.e., when the fixed contact 2 is fixed to the switching chamber, the fixing part 20 may have lower hardness than the connector 21 due to the hard soldering process. Due to the typical high temperature during hard soldering, for example, 800°C or higher, the material of the fixing part 20 may become softer after hard soldering due to a solid-phase physical process. In contrast, the connector 21 does not undergo the hard soldering process and is screwed in after hard soldering, so it can maintain its original hardness.

[0070] The fixed portion 20 is soldered to the switching chamber cover, which may soften it, while the connector portion 21, made of the same material, remains untreated as it will be fixed later. The T-shape of the harder connector portion 21, recognizable in the cross-sectional view of Figure 2E, facilitates frictional bonding with the fixed portion 20 and prevents shear forces that may later act on the connector element 211 from damaging the female thread 207 of the fixed portion 20 via leverage. Even with a relatively small tightening torque of about 4 Nm, the electrical contact resistance added by the two-part shape of the fixed contact 2 has been shown to be negligible.

[0071] Figures 4-8B below show further embodiments of the fixed contact 2 that can improve the permanent connection between the fixed portion 20 and the connecting portion 21. For clarity, only the components described are shown in Figures 4-8B, along with their reference numerals. The measures described may be used individually or in combination.

[0072] As shown in Figure 4, a bonding material 23 may be placed between the male thread 217 of the coupling element 216 of the connection part 21 and the female thread 207 of the recess 200 of the fixing part 20, as indicated by the dashed line area. The bonding material 23 may include, for example, an acrylate such as methacrylic resin or cyanoacrylate, or an adhesive made of the same, or it may be an adhesive. The adhesive hardens after the connection part 21 is attached to the fixing part 20, preventing the connection part 21 from unintentionally loosening.

[0073] As shown in Figure 5, the bonding material 24 can be placed in a recess 200 below the bonding element 216 of the connecting element 21. For this purpose, the recess 200 is preferably deeper than the height of the bonding element 216 as measured from the lower surface 215 of the support element 213, so that when the connecting portion 21 is fully screwed into the fixing portion 20, a cavity remains below the bonding element 216 in which the bonding material 24 can be placed. The bonding material 24 may include or consist of an adhesive, such as the adhesive described above, or, particularly preferably, a soft solder. The soft solder may be placed, for example, in the form of a solder pill in the recess 200 of the fixing portion 20, which is already fixed to the switching chamber. After the connecting portion 21 is screwed in, the soft solder can be melted, for example, by heating in a furnace, at a temperature significantly lower than in the hard soldering process, and without causing softening of the connecting portion 21. As generally described above, soft solder is preferably lead-free and, for example, based on Bi, Sn and / or Sb, or based on Sn and Ag and / or Cu. Soft solder may be flux-free, resulting in no flux residue remaining in the void. Alternatively, soft solder may be supplied with flux. The flux may, for example, improve the wettability of the soft solder.

[0074] As shown in Figure 6, a bonding material 25 may be placed between the lower surface 215 of the support element 213 of the connecting portion 21 and the upper surface 204 of the edge region 203 of the fixing portion 20. For example, the bonding material 25 may include or consist of an adhesive, or, particularly preferably, a soft solder as described above.

[0075] Therefore, for the advanced configurations shown in Figures 5 and 6, before the connector 21 is screwed into the fixed part 20, a bonding material 24, 25, particularly preferably in the form of soft solder, can be applied near the threads in the recess 200, or on the outer edge, i.e., on the support surface formed by the upper surface 204 of the edge region 203. For example, after the connector 21 is installed, the solder containing flux can be melted to a melting point of preferably 300°C or less, which results in melting and subsequently a strong bond. The low melting point of the soft solder avoids a decrease in the hardness of the connector 21, because this typically only occurs at temperatures above 500°C in the case of copper and copper alloys. During operation of the switching device, the temperature of the fixed contact 2 typically remains below 160°C, which prevents further melting of the soft solder. Introducing the bonding material 25 to the outer edge has the advantage of increasing the torque required to loosen the soft solder bond.

[0076] Furthermore, as shown in Figures 7A and 7B, the upper surface 204 of the edge region 203 of the fixing portion 20 and / or the lower surface 215 of the support element 213 of the connecting portion 21 may have surface structures 209, 219, such as knurling and / or surface roughening, which can be manufactured by sandblasting, for example. The surface structures 209, 219 may be provided in relation to the bonding material 25 between the lower surface 215 of the support element 213 and the upper surface 204 of the edge region 203, particularly preferably.

[0077] As shown in Figures 8A and 8B, the support element 213 of the connection portion 21 can be welded to the edge region 203 of the fixed portion 20. After screwing the connection portion 21 to the fastening portion 20, the contact edge is welded all around or partially around the edge. In particular, the support element 213 can be joined to the edge region 203 by a welded seam 26, indicated by the dashed area in Figure 8A, outside the contact area formed by the lower surface 215 of the support element 213 and the upper surface 204 of the edge region 203, and the welded seam 26 may, particularly preferably, completely surround the edge. The welded seam 26 may, particularly preferably, be formed by laser welding. Welding has the advantage of a short process time. Furthermore, a high level of safety can be achieved against the connection portion 21 unintentionally detaching from the fixed portion 20 during use of the switching device.

[0078] The surfaces of the parts to be joined may be prepared so that the laser beam can effectively deliver energy and beam reflection can be prevented. As shown in Figure 8B, for this purpose, an absorbing element 27 may be placed in the welding area, which may be formed, for example, by a suitable paint, varnish or roughening.

[0079] Features and embodiments described in relation to the drawings can be combined with each other according to further embodiments, even if not all combinations are explicitly described. Furthermore, embodiments described in relation to the drawings may have additional features by description of general parts, either alternatively or additionally.

[0080] The present invention is not limited to the examples described herein. Rather, the present invention includes all new features, and in particular all combinations of features, including all combinations of features in the claims, even if such features or combinations themselves are not explicitly presented in the claims or examples. [Explanation of Symbols]

[0081] 1 Housing 2 Fixed contacts 3. Insulator 4. Contact Bridge 5. Magnetic Armature 6 magnetic core 7 axes 8 coils 9 York 10 springs 11 Switching Chamber 12 Switching Chamber Cover 13. Bottom of the switching chamber 14. Airtight zone 15 Interior space 16 permanent magnets 17 Gas filling nozzle 20 Fixed part 21 Connection part 23,24,25 Bonding material 26 Welded joints 27 Absorption elements 28 Laser light 34 Contact spring 100 Switching devices 101,102 aperture 122 Mounting area 123 Fixed edge 120 Hard Solder 200 recess 201 Bottom area 202 Wall area 203 Edge area 204 Top surface 205 Fixed edge 206 Groove 207 Female thread 208 Contact surface 209 Surface structure 211 Connection elements 212 Male screw 213 Support elements 214 Top surface 215 Bottom surface 216 connecting elements 217 Male screw 219 Surface structure

Claims

1. A switching device (100) having at least one fixed contact (2) protruding into a switching chamber (11), The at least one fixed contact (2) has a fixed portion (20) and a connecting portion (21), The fixed portion (20) is fixed to the switching chamber (11), The connecting portion (21) protrudes into the recess (200) of the fixing portion (20), The switching device (100) has at least one of the following features [1] to [4]. [1] The connecting portion (21) and the fixing portion (20) are manufactured from the same material, the contacts contain copper or a copper alloy, and the fixing portion (20) has a lower hardness than the connecting portion (21). [2] The connecting portion (21) is located outside the housing (1) of the switching device (100) and includes a connecting element (211) formed by stud bolts and a support element (213), wherein the connecting element (211) extends away from the support element (213), and the support element (213) has a lower surface (215) facing the switching chamber (11), and the connecting portion (21) rests on the fixing portion (20) with its lower surface (215), and the fixing portion (20) has an edge region (203) with an upper surface (204), and the lower surface (215) of the support element (213) rests on the upper surface (204), A bonding material (25) including soft solder is disposed between the lower surface (215) of the support element (213) and the upper surface (204) of the edge region (203), and / or The support element (213) is welded to the edge region (203), and / or The edge region (203) has a fixed edge portion (205) facing the switching chamber (11), and the fixed edge portion (205) is bonded to the switching chamber (11) by intermolecular forces. [3] The connecting portion (21) protrudes into the recess (200) of the fixing portion (20) by a coupling element (216), and is screwed into the recess (200) by the coupling element (216), the coupling element (216) has a male thread (217), the recess (200) of the fixing portion (20) has a female thread (207), and the male thread (217) and / or the female thread (207) have an interference fit before the connecting portion (21) is screwed into the fixing portion (20). [4] A bonding material (24) containing soft solder is placed in the recess (200) below the connecting element (211).

2. The fixing portion is formed in a cup shape, and the recess is formed as a blind hole, the switching device (100) according to claim 1.

3. The switching device (100) according to claim 1 or 2, wherein the upper surface (204) of the edge region (203) of the fixing portion (20) and / or the lower surface (215) of the support element (213) of the connecting portion (21) have a surface structure (209, 219), and the surface structure (209, 219) is knurled and / or roughened.

4. The switching device (100) according to claim 1 or 2, wherein the support element (213) is joined to the edge region (203) by a welded joint outside the contact region formed by the lower surface (215) of the support element (213) and the upper surface (204) of the edge region (203).

5. The switching device (100) according to claim 4, wherein the welded joint completely surrounds the periphery.

6. The switching device (100) according to claim 1 or 2, wherein there is a cavity in the recess (200) below the connecting element (211), and the bonding material (24) is disposed in the cavity.

7. The switching device (100) according to claim 1 or 2, wherein the soft solder of the bonding material (24) contains bismuth, tin, and antimony, with the mass-based proportions of bismuth and tin being 25% or more and 35% or less, and the mass-based proportion of antimony being 50% or more and 70% or less.

8. The switching device (100) according to claim 1 or 2, wherein the soft solder of the bonding material (24) contains bismuth, tin, and antimony, with the mass-based proportions of bismuth and tin being 27% or more and 31% or less, and the mass-based proportion of antimony being 38% or more and 46% or less.

9. The switching device (100) according to claim 1 or 2, wherein the soft solder of the bonding material (24) contains tin, silver, and copper, with a mass-based proportion of tin being 50% or more, a mass-based proportion of silver being less than 15%, and a mass-based proportion of copper being less than 5%.

10. The switching device (100) according to claim 9, wherein the soft solder is Sn96.5Ag3.0Cu0.

5.

11. A switching device (100) according to claim 1 or 2, wherein a bonding material (23) containing an adhesive is disposed between the male screw (217) and the female screw (207).

12. The switching device (100) according to claim 1 or 2, wherein the switching device (100) has a housing (1) in which the switching chamber (11) is disposed, and the upper surface (204) of the edge region (203) and the lower surface (215) of the support element (213) are disposed inside the opening (101) of the housing (1).

13. The switching device (100) according to claim 1 or 2, wherein the upper surface (204) of the edge region (203) and the lower surface (215) of the support element (213) are both formed in a ring shape and are arranged to coincide on top of each other.

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