Switching Device

Abstract

In an embodiment a switching device includes at least one stationary contact, a movable contact, an armature, a first permanent magnet, a second permanent magnet and a magnetic switch, wherein the movable contact is movable by the armature, wherein the first permanent magnet is attached to the armature, and wherein the second permanent magnet is arranged in a fixed position relative to the magnetic switch.

Claims

1.-14. (canceled)

15. A switching device comprising: at least one stationary contact; a movable contact; an armature; a first permanent magnet; a second permanent magnet; and a magnetic switch, wherein the movable contact is movable by the armature, wherein the first permanent magnet is attached to the armature, and wherein the second permanent magnet is arranged in a fixed position relative to the magnetic switch.

16. The switching device as claimed in claim 15, wherein the magnetic switch is a reed switch.

17. The switching device as claimed in claim 15, wherein the magnetic switch is a normally-open switch.

18. The switching device as claimed in claim 15, wherein the second permanent magnet is configured to generate a magnetic field through which the magnetic switch is kept in a closed state in absence of further magnetic fields.

19. The switching device as claimed in claim 15, wherein the magnetic switch is kept in a closed state by the second permanent magnet in a switched on state of the switching device.

20. The switching device as claimed in claim 15, wherein the first permanent magnet is configured to generate a magnetic field which weakens the magnetic field of the second permanent magnet in a switched off state of the switching device.

21. The switching device as claimed in claim 15, wherein a magnetic field of the first permanent magnet weakens a magnetic field of the second permanent magnet in a switched off state of the switching device such that the magnetic switch is present in an open state.

22. The switching device as claimed in claim 15, wherein the first permanent magnet is arranged at an end of the armature facing away from the movable contact.

23. The switching device as claimed in claim 15, wherein the armature has a magnetic core and a shaft, and wherein the first permanent magnet is attached to the magnetic core and/or to the shaft.

24. The switching device as claimed in claim 15, wherein the first permanent magnet is a ring magnet arranged symmetrically to a shaft of the armature.

25. The switching device as claimed in claim 15, wherein the contacts, the armature and the first permanent magnet are arranged inside a gas-tight region.

26. The switching device as claimed in claim 25, wherein the magnetic switch and the second permanent magnet are arranged outside the gas-tight region.

27. The switching device as claimed in claim 26, wherein the gas-tight region contains a gas and the gas contains H.sub.2.

28. The switching device as claimed in claim 27, wherein the gas has a proportion of at least 50% H.sub.2.

29. A switching device comprising: at least one stationary contact; a movable contact; an armature; a first permanent magnet; a second permanent magnet; and a magnetic switch, wherein the movable contact is movable by the armature, wherein the first permanent magnet is attached to the armature, wherein the second permanent magnet is arranged in a fixed position relative to the magnetic switch, wherein the contacts, the armature and the first permanent magnet are arranged inside a gas-tight region, and wherein the magnetic switch and the second permanent magnet are arranged outside the gas-tight region.

30. The switching device as claimed in claim 29, wherein the first permanent magnet is a ring magnet.

31. The switching device as claimed in claim 30, wherein the ring magnet is arranged symmetrically to a shaft of the armature.

32. A switching device comprising: at least one stationary contact; a movable contact; an armature; a first permanent magnet; a second permanent magnet; and a magnetic switch, wherein the movable contact is movable by the armature, wherein the first permanent magnet is attached to the armature, wherein the second permanent magnet is arranged in a fixed position relative to the magnetic switch, and wherein the first permanent magnet is a ring magnet arranged inside a gas-tight region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further advantages, advantageous embodiments and developments are set forth in the exemplary embodiments which are described hereinafter in connection with the figures.

[0024] In the figures:

[0025] FIGS. 1A and 1B show schematic illustrations of an example for a switching device; and

[0026] FIGS. 2A to 2C show schematic illustrations of a part of the switching device according to an exemplary embodiment.

[0027] In the exemplary embodiments and figures, identical, similar or identically-functioning elements can be provided in each case with the same reference numerals. The illustrated elements and their size ratios with respect to one another are not to be regarded as being true to scale, on the contrary individual elements, such as for example, layers, components, structural elements and regions can be illustrated in an excessively large manner in order to improve the presentability and/or to improve the understanding of the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0028] FIGS. 1A and 1B show a switching device 100 which can be used for switching strong electrical currents and/or high electrical voltages, for example, and which can be a relay or contactor, in particular a power contactor. FIG. 1A shows a three-dimensional sectional illustration, while FIG. 1B represents a two-dimensional sectional illustration. The subsequent description similarly relates to FIGS. 1A and 1B. The geometries shown are only exemplary and are not intended to be understood to be limiting and can also be designed alternatively.

[0029] The switching device 100 has two stationary contacts 2, 3 and a movable contact 4 in a housing 1. The movable contact 4 is designed as a contact plate. The stationary contacts 2, 3, together with the movable contact 4, form the switch contacts. Alternatively to the number of contacts shown, other numbers of fixed and/or movable contacts may also be possible. The housing 1 serves primarily as protection against contact for the components arranged in the interior and includes or is made of a plastics material, for example PBT or fiberglass-filled PBT. The contacts 2, 3, 4 can, for example, be made with or of Cu, a Cu alloy or a combination of copper with at least one further metal, for example W, Ni and/or Cr.

[0030] FIGS. 1A and 1B show the switching device 100 in an idle state in which the movable contact 4 is spaced apart from the stationary contacts 2, 3, so that the contacts 2, 3, 4 are galvanically isolated from one another. The embodiment shown of the switch contacts and in particular their geometry are intended to be understood to be purely exemplary and not limiting. Alternatively, the switch contacts may also be designed in a different way. For example, it may be possible that only one of the switch contacts is designed to be fixed.

[0031] The switching device 100 has a movable armature 5 which essentially carries out the switching movement. The armature 5 has a magnetic core 6, for example made with or of a ferromagnetic material. Moreover, the armature 5 has a shaft 7 which is guided through the magnetic core 6 and is fixedly connected to the magnetic core 6 at a shaft end. At the other shaft end, which is opposite the magnetic core 6, the armature 5 has the movable contact 4 which is also connected to the shaft 7. The shaft 7 can preferably be manufactured with or from stainless steel.

[0032] The magnetic core 6 is surrounded by a coil 8. A current flow in the coil 8, which current flow can be connected from the outside by way of a control circuit, generates a movement of the magnetic core 6 and thus of the entire armature 5 in the axial direction, until the movable contact 4 contacts the stationary contacts 2, 3. In the illustration shown, the armature moves upward. The armature 5 therefore moves from a first position, which corresponds to the shown idle state and at the same time the disconnected, i.e. non-switched-through and therefore switched off state, into a second position, which corresponds to the active, i.e. switched-through and thus switched on state. In the active state, the contacts 2, 3, 4 are galvanically connected to one another. If the current flow in the coil 8 is interrupted, the armature 5 is moved into the first position again by way of one or a plurality of springs 10. In the illustration shown, the armature 5 thus moves downward again. The switching device 100 is then in the idle state again, in which the contacts 2, 3, 4 are open.

[0033] When the contacts 2, 3, 4 are opened, an electric are may arise which can damage the contact surfaces. This can result in the risk of the contacts 2, 3, 4 becoming “stuck” together and no longer disconnecting from one another as a result of welding caused by the electric arc. Consequently, the switching device then continues to be in the switched on state, despite the fact that the current in the coil is switched off and therefore the load circuit should be disconnected. In order to prevent an electric arc of this type from arising or in order to at least facilitate extinguishing electric arcs which occur, the contacts 2, 3, 4 are arranged in a gaseous atmosphere, such that the switching device 100 is designed as a gas-filled relay or gas-filled contactor. For this purpose, the contacts 2, 3, 4 are arranged inside a switching chamber 11, formed by a switching chamber wall 12 and a switching chamber floor 13, in a gas-tight region 16 which is formed by a hermetically sealed part. The gas-tight region 16 completely surrounds the armature 5 and the contacts 2, 3, 4 except for parts of the stationary contacts 2, 3 which are provided for external connection. The gas-tight region 16 and thus also the switching chamber 11 are filled with a gas 14. The gas-tight region 16 is essentially formed by parts of the switching chamber 11, the yoke 9 and additional walls. The gas 14, which can be poured into the gas-tight region 16 by way of a gas filling nozzle 15 within the framework of the production of the switching device 100, can particularly preferably contain hydrogen, for example with 50% or more H.sub.2 in an inert gas or even with 100% H.sub.2, since gas which contains hydrogen can facilitate extinguishing electric arcs. Moreover, so called blow magnets (not shown) can be present inside or outside the switching chamber 11, i.e. permanent magnets which bring about an extension of the electric are path and thus can improve the extinguishing of the electric arc. The switching chamber wall 12 and the switching chamber floor 13 can be manufactured with or from a metal oxide, for example, such as Al.sub.2O.sub.3, for example. Moreover, plastics materials with a sufficiently high temperature stability, for example a PEEK, a PE and/or a glass-filled PBT, are also suitable. Alternatively or additionally, the switching chamber 11 can at least partially also include a POM, in particular with the structure (CH.sub.2O).sub.n.

[0034] In order to obtain information regarding the actual position of the movable contact 4 and thus with respect to a possible stuck contactor, for example, the switching device 100 has further components which are not shown in FIGS. 1A and 1B for the sake of clarity and which are described in connection with FIGS. 2A to 2C. Moreover, the switching device 100 has in particular a first permanent magnet 17, a second permanent magnet 18 and a magnetic switch 19. FIG. 2A essentially only shows those components and parts of the switching device 100 from FIGS. 1A and 1B which form the gas-tight region 16 of the switching device 100. FIGS. 2B and 2C show simplified cut-outs thereof. Unless otherwise described, the components and parts shown in FIGS. 2A to 2C as well as the components and parts of the switching device 100 which are not shown in FIGS. 2A to 2C in comparison to FIGS. 1A and 1B correspond to the components and parts which are described in connection with FIGS. 1A and 1B.

[0035] The first permanent magnet 17, together with the contacts 2, 3, 4 and the armature 5, is arranged inside the gas-tight region 16 and is in particular attached to the end of the armature 5 which faces away from the movable contact 4. As a result, the first permanent magnet 17 can be moved together with the movable contact 4 by way of the armature 5.

[0036] As represented in FIG. 2A, the first permanent magnet 17 can be designed as a ring magnet and be attached to the magnetic core 6 of the armature 5. Alternatively to this, the first permanent magnet 17 can also be designed as a bar magnet or disc magnet and alternatively or additionally can also be attached to the shaft 7. Alternatively to the represented arrangement of the first permanent magnet 17, symmetrical in relation to the shaft 7, the first permanent magnet 17 can also be arranged and attached in a different position, in particular if the functionality described hereinafter, together with the second permanent magnet 18 and the magnetic switch 19, can be improved as a result.

[0037] The second permanent magnet 18, together with the magnetic switch 19, is arranged outside the gas-tight region 16 inside the housing of the switching device 100 not shown in FIGS. 2A to 2C. In particular, the second permanent magnet 18 and the magnetic switch 19 in the housing are each installed in a fixed position, so that the second permanent magnet 18 is arranged in a fixed position relative to the magnetic switch 19. The second permanent magnet 18 can be a bar magnet or alternatively also a ring magnet or disc magnet, for example. As represented in FIGS. 2A to 2C, the second permanent magnet 18 and the magnetic switch 19 can be arranged along the movement direction of the armature 5 below the first permanent magnet 17. In this case, an arrangement symmetrical to the shaft 7 may be possible, as shown. As already mentioned in relation to the first permanent magnet 17, the positions of the second permanent magnet 18 and/or the magnetic switch 19 can also deviate from the positions shown, in particular if the functionality of said components can be improved as a result.

[0038] The magnetic switch 5 is designed as a simple reed switch. A shown in FIGS. 2B and 2C, the magnetic switch can have contact tongues 191, for example in a melted shut glass tube 192 with protective gas filling or vacuum, which, depending on the acting magnetic field, are mechanically disconnected from one another, which corresponds to the open state of the magnetic switch 19, or touch one another, which corresponds to the closed state of the magnetic switch 19. In particular, the magnetic switch 5 is designed in the form of a normally-open switch and thus in an open switching state in the absence of magnetic fields.

[0039] The second permanent magnet 18 is designed and arranged relative to the magnetic switch 19 in such a way that the magnetic field, which is generated by the second permanent magnet 18 at the location of the magnetic switch 19, is so large that the magnetic switch 19 is in a closed state at least in the absence of further magnetic fields. The second permanent magnet 18 thus generates a sufficiently large magnetic field that the magnetic switch 19 is always kept in a closed state in the absence of further magnetic fields. The first permanent magnet 17 is arranged and designed in such a way that it can at least partially compensate the magnetic field of the second permanent magnet 18 if at a sufficiently short distance from the magnetic switch 19 and from the second permanent magnet 18. However, if the first permanent magnet 17 is far enough away from the magnetic switch 19 and from the second permanent magnet 18, a compensation does not occur or only such a low compensation that the magnetic switch 19 is kept in the closed state by the magnetic field of the second permanent magnet 18. This is the case in particular if the switching device 100 is in the switched on state and the armature 5, with the movable contact 4 and the first permanent magnet 17, is arranged at a maximum distance from the magnetic switch 19. This state is shown in FIG. 2B, wherein in FIG. 2B as in FIG. 2C, only the positions of the permanent magnets 17, 18 and the magnetic switch 19 are indicated, without the remaining components of the switching device. Owing to the arrangement and design of the second permanent magnet 18, the magnetic switch is therefore closed if the switching device 100 is also in the switched on state, i.e. the movable contact 4 is in mechanical contact with the stationary contacts 2, 3.

[0040] According to the previous description, the magnetic switch 19 and the first permanent magnet 17 are arranged relative to one another in such a way that the magnetic field generated by the first permanent magnet at the location of the magnetic switch is weaker in the switched on state of the switching device 100 than in the switched off state of the switching device 100. In the switched off state of the switching device 100, the first permanent magnet 17, as shown in FIG. 2C, is located so close to the magnetic switch 19 and to the second permanent magnet 18 that the magnetic field of the second permanent magnet 18 is strongly compensated in such a way that the resulting magnetic field is no longer large enough in order to keep the magnetic switch 19 in the closed state and the magnetic switch 19 is in an open state. Correspondingly, the magnetic switch 19 is in an open state if the switching device 100 is in the switched off state.

[0041] By detecting the state of the magnetic switch 19, for example by means of a resistance measurement, the state of the switching device 100 can thus be directly identified. In particular, it can be easily identified if the switching device 100 is still in the active state as a result of a stuck contactor, despite the fact that the current for the coil which moves the armature 5 is already switched off and the switching device 100 should correspondingly be in the non-active state.

[0042] The features and exemplary embodiments described in conjunction with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations have been explicitly described. Furthermore, the exemplary embodiments described in conjunction with the figures may alternatively or additionally include further features in accordance with the description in the general part.

[0043] The invention is not restricted to the exemplary embodiments by the description on the basis of said exemplary embodiments. Rather, the invention encompasses any novel feature and any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or this combination is not itself explicitly specified in the patent claims or exemplary embodiments.