Switching Device

Abstract

In an embodiment, a switching device includes at least one stationary contact, a movable contact, an armature, a permanent magnet and a magnetically-operated switch, wherein the movable contact is movable by the armature, wherein the permanent magnet is attached to the armature, and wherein the magnetically-operated switch is a Hall switch.

Claims

1-16. (canceled)

17. A switching device comprising: at least one stationary contact; a movable contact; an armature; a permanent magnet; and a magnetically-operated switch, wherein the movable contact is movable by the armature, wherein the permanent magnet is attached to the armature, and wherein the magnetically-operated switch is a Hall switch.

18. The switching device as claimed in claim 17, wherein the magnetically-operated switch is configured to be in a state selected from a first state and a second state depending on a magnetic field.

19. The switching device as claimed in claim 18, wherein the magnetically-operated switch is configured to generate a first current in the first state and a second current in the second state, the second current being different to the first current.

20. The switching device as claimed in claim 18, wherein the magnetically-operated switch is in the first state or in the second state depending on a distance of the permanent magnet to the magnetically-operated switch.

21. The switching device as claimed in claim 17, wherein the permanent magnet is arranged at an end of the armature remote from the movable contact.

22. The switching device as claimed in claim 17, wherein the armature comprises a magnetic core and a shaft, and wherein the permanent magnet is attached to the magnetic core and/or to the shaft.

23. The switching device as claimed in claim 22, wherein the permanent magnet is a ring magnet arranged symmetrically with respect to the shaft of the armature.

24. The switching device as claimed in claim 17, wherein the contacts, the armature and the permanent magnet are arranged within a gas-tight region.

25. The switching device as claimed in claim 24, wherein the magnetically-operated switch is arranged outside the gas-tight region.

26. The switching device as claimed in claim 17, wherein the magnetically-operated switch is connected to a signal processing device.

27. The switching device as claimed in claim 26, wherein the signal processing device comprises a measuring resistor connected in series to the magnetically-operated switch.

28. The switching device as claimed in claim 27, wherein the signal processing device comprises a comparator configured to compare a voltage drop across the measuring resistor with a reference voltage.

29. The switching device as claimed in claim 28, wherein the reference voltage is predetermined by a Zener diode.

30. The switching device as claimed in claim 29, wherein the magnetically-operated switch, the Zener diode and the comparator are connected to a common voltage supply.

31. The switching device as claimed in claim 28, wherein the signal processing device comprises an electronic switch having a control input connected to an output of the comparator.

32. The switching device as claimed in claim 31, wherein the control input of the electronic switch is connected to the output of the comparator via a voltage divider.

33. A switching device comprising : a movable contact being movable by an armature; a permanent magnet attached to the armature; a magnetically-operated switch being a Hall switch; and a signal processing device comprising: a measuring resistor connected in series to the magnetically-operated switch; a comparator configured to compare a voltage drop across the measuring resistor with a reference voltage, the reference voltage being predetermined by a Zener diode; and an electronic switch having a control input connected to an output of the comparator, wherein the magnetically-operated switch, the Zener diode and the comparator are connected to a common voltage supply, and wherein the control input of the electronic switch is connected to the output of the comparator via a voltage divider.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further advantages, advantageous embodiments and developments are apparent from the exemplary embodiments described below in connection with the FIGS. .

[0029] In the drawings:

[0030] FIGS. 1A and 1B show schematic illustrations of an example for a switching device;

[0031] FIG. 2 shows a schematic illustration of a part of the switching device in accordance with an exemplary embodiment; and

[0032] FIGS. 3A to 3C show schematic illustrations of signal processing devices and parts thereof in accordance with further exemplary embodiments.

[0033] In the exemplary embodiments and FIGS., 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

[0034] FIGS. 1A and 1B illustrate a switching device 100 that can be used for example to switch strong electrical currents and/or high electrical voltages and can be a relay or a contactor, for example a power contactor. Figure IA illustrates a three-dimensional sectional view, whereas FIG. 1B illustrates a two-dimensional sectional view. The description below relates equally to FIGS. 1A and 1B. The different geometries are only exemplary and not to be understood as limiting and can also be embodied in an alternative manner.

[0035] The switching device wo comprises in a housing 1 two stationary contacts 2, 3 and a movable contact 4. The movable contact 4 is embodied as a contact plate. The stationary contacts 2, 3 together with the movable contact 4 form the switching contacts. Alternatively to the illustrated number of contacts, other numbers of stationary and/or movable contacts are also possible. The housing 1 is used primarily as a contact protection for the components that are arranged inside and comprises or is embodied from a synthetic material, for example PBT or glass fiber-filled PBT. The contacts 2, 3, 4 can for example comprise or be embodied from Cu, a Cu alloy, or a mixture of copper comprising at least one further metal, for example W, Ni and/or Cr.

[0036] FIGS. 1A and 1B illustrate the switching device wo in an idle state in which the movable contact 4 is at a distance from the stationary contacts 2, 3 with the result that the contacts 2, 3, 4 are galvanically separated from one another. The illustrated design of the switching contacts and in particular their geometries are to be understood as a mere example and not as limiting. Alternatively, the switching contacts can also be embodied differently. For example, it can be possible that only one of the switching contacts is embodied in a stationary manner.

[0037] The switching device wo comprises a movable armature 5 that fundamentally performs the switching movement. The armature 5 comprises a magnetic core 6, for example comprising or embodied from a ferromagnetic material. Furthermore, the armature 5 comprises a shaft 7 that is guided through the magnetic core 6 and is fixedly connected at one shaft end to the magnetic core 6. At the other shaft end that lies opposite the magnetic core 6, the armature 5 comprises the movable contact 4 that is likewise connected to the shaft 7. The shaft 7 can preferably be manufactured comprising or embodied from high-grade steel.

[0038] The magnetic core 6 is surrounded by a coil 8. A current flow in the coil 8 which can be switched on from the outside by means of a control current circuit generates a movement of the magnetic core 6 and consequently of the entire armature 5 in the axial direction, until the movable contact 4 contacts the stationary contacts 2, 3. In the illustrated view, the armature moves upwards. The armature 5 consequently moves from a first position, which corresponds to the illustrated idle position and simultaneously the separated state, in other words non-conducting and thus switched-off state, into a second position that corresponds to the active, in other words conducting and thus switched-on, state. In the active state, the contacts 2, 3, 4 are connected to one another in a galvanic manner. In a different embodiment, the armature 5 can alternatively also perform a rotational movement. The armature 5 can be embodied in particular as a pulling armature or a folding armature. If the current flow in the coil 8 is interrupted, the armature 5 is moved by means of one or multiple springs lo back into the first position. In the illustrated view, the armature 5 consequently moves back downwards. The switching device wo is then located back in the idle state in which the contacts 2, 3, 4 are open.

[0039] As the contacts 2, 3, 4 open, it is possible for a flashover to occur which can damage the contact surfaces. As a consequence, there is the risk that the contacts 2, 3, 4 remain “stuck” to one another by virtue of becoming welded as a result of the flashover and can no longer be separated from one another. Consequently, the switching device is then in the switched-on state although the current in the coil is switched off and consequently the load current circuit must have been separated. In order to prevent flashovers of this type occurring or in order at least to support the procedure of extinguishing flashovers that occur, the contacts 2, 3, 4 are arranged in a gas atmosphere with the result that the switching device wo is embodied as a gas-filled relay or gas-filled contactor. For this purpose, the contacts 2, 3, 4 are arranged in a switching chamber 11, which is formed by means of a switching chamber wall 12 and a switching chamber base 13, in a gas-tight region 16 that is formed by means of a hermetically sealed part. The gas-tight region 16 completely surrounds the armature 5 and the contacts 2, 3, 4 apart from parts of the stationary contacts 2, 3 that are provided for the external terminal. The gas-tight region 16 and consequently also the switching chamber 11 are filled with a gas 14. The gas-tight region 16 is formed fundamentally by means of parts of the switching chamber 11, of the yoke 9 and additional walls. The gas 14 that can be filled into the gas-tight region 16 by means of a gas-filling port 15 within the scope of producing the switching device 100 can particularly preferably contain hydrogen, for example with 50% or more H2 in an inert gas or even with 100% H.sub.2, since hydrogen-containing gas can promote the procedure of extinguishing flashovers. Furthermore, so-called blowout magnets (not illustrated) can be provided inside or outside the switching chamber 11, in other words permanent magnets that extend the flashover path and consequently can improve the procedure of extinguishing the flashovers. The switching chamber wall 12 and the switching chamber base 13 can be manufactured for example comprising or embodied from a metal oxide such as Al.sub.2O.sub.3. Furthermore, synthetic materials that have sufficiently high temperature stability are suitable, for example a PEEK, a PE and/or a glass-filled PBT. Alternatively or in addition, the switching chamber 11 can comprise at least in part also a POM, in particular having the structure (CH.sub.2O).sub.n.

[0040] In order to obtain information regarding the actual position of the movable contact 4 and consequently for example with regard to a possible stuck contactor, the switching device 100 comprises further components that for the sake of clarity are not illustrated in FIGS. 1A and 1B and are described in connection with FIGS. 2 and 3A to 3C. The switching device loo comprises in particular furthermore a permanent magnet 17 and a magnetically-operated switch 19. Furthermore, the switching device wo comprises in the illustrated exemplary embodiment a signal processing device 20. Alternatively thereto, the switching device in accordance with a further embodiment can also not comprise a signal processing device. Fundamentally only the components and parts of the switching device 100 that are shown in FIGS. 1A and iB and form the gas-tight region 16 of the switching device 100 are illustrated in FIG. 2. Exemplary embodiments for the signal processing device 20 and parts thereof are illustrated in FIGS. 3A to 3C. Insofar as not otherwise described, the components and parts illustrated in FIG. 2 and also components and parts of the switching device 100 not illustrated in FIG. 2 in comparison to the FIGS. 1A and iB correspond to components and parts that are described in connection with FIGS. 1A and 113.

[0041] The permanent magnet 17 is arranged together with the contacts 2, 3, 4 and the armature 5 within the gas-tight region 16 and is in particular attached thereto at the end of the armature 5 that is remote from the movable contact 4. As a consequence, the permanent magnet 17 can be moved by means of the armature 5 jointly with the movable contact 4.

[0042] As illustrated in FIG. 2, the permanent magnet 17 can be embodied as a ring magnet and can be attached to the magnetic core 6 of the armature 5. Alternatively thereto, the permanent magnet 17 can also be embodied as a rod magnet or disc magnet and alternatively or in addition also be attached to the shaft 7. Alternatively to the illustrated arrangement of the permanent magnet 17 in a symmetrical manner with regard to the shaft 7, the permanent magnet 17 can also be arranged and attached at a different position, in particular if as a consequence the functionality described below together with the magnetically-operated switch 19 can be improved.

[0043] The magnetically-operated switch 19 is arranged together with the signal processing device 20 outside the gas-tight region 16 within the housing (not illustrated in FIG. 2) of the switching device 100. It is particularly preferred that the magnetically-operated switch 19 and the signal processing device 20 can be connected to one another and furthermore can be arranged on a common printed circuit board, as indicated by the broken line in FIG. 2.

[0044] The magnetically-operated switch 19 is a Hall switch as described above in the general part and comprises a current output which depending upon the state of the Hall switch is provided with a first current or a second current. In particular, the magnetically-operated switch 19 is embodied as a Hall switch that is sensitive to the magnetic south pole of the permanent magnet 17 that is arranged accordingly with its south pole facing the magnetically-operated switch 19. According to the operating principle described above in the general part, the magnetically-operated switch 19 is otherwise relatively insensitive to interference fields. For the operation of the magnetically-operated switch 19, said magnetically-operated switch is permanently connected to a voltage supply (not illustrated) at least during the period of use of the switching device 100, as is described in detail in connection with FIGS. 3A to 3C.

[0045] By virtue of the fact that the permanent magnet 17 is attached to the armature 5, the permanent magnet 17 can be moved as described above simultaneously as a result of the switching movement of the armature 5 as the switching device 100 is switched, and as the switching device 100 is switched on into its active switched state said permanent magnet is moved away from the magnetically-operated switch 19 and as the switching device 100 is switched off into its non-active switched state said permanent magnet is moved back toward said magnetically-operated switch 19 with the result that in the case of the switched-on state of the switching device 100 the permanent magnet 17 is at a greater distance from the magnetically-operated switch 19 than in the case of the switched-off state of the switching device 100. Accordingly, the magnetic field that is generated by the permanent magnet 17 at the site of the magnetically-operated switch 19 in the case of the switched-on state of the switching device 100 is weaker than in the case of the switched-off state of the switching device 100. In particular, in the case of the switched-off state of the switching device 100, a first magnetic field strength that is produced by means of the permanent magnet 17 prevails at the site of the magnetically-operated switch 19 and in the case of the switched-on state of the switching device 100 a second magnetic field prevails, wherein the magnetic field strength as described above in the general part relates in particular to the component of the prevailing magnetic field which the magnetically-operated switch is sensitive to.

[0046] The magnetically-operated switch 19 is configured and dimensioned in such a manner that during operation in dependence upon a distance the permanent magnet 17 is from the magnetically-operated switch 19, the magnetically-operated switch 19 is in a first state or in a second state. This means in other words that in the case of the switched-off state of the switching device 100 the magnetic field produced by means of the permanent magnet 17 at the site of the magnetically-operated switch 19 is stronger than a threshold magnetic field and in the case of the switched-on state of the switching device 100 is less than a threshold magnetic field, wherein the threshold magnetic field indicates the magnetic field strength that is detected by the magnetically-operated switch, at which the magnetically-operated switch 19 switches from the first state into the second state or conversely. Merely as an example, the state in which the magnetically-operated switch 19 is in the case of the switched-off state of the switching device 100, in other words if the permanent magnet 17 is at a small distance from the magnetically-operated switch 19, is referred to as the first state of the magnetically-operated switch 19, whereas the state in which the magnetically-operated switch 19 in the case of the switched-on state of the switching device 100, in other words if the permanent magnet 17 is at a great distance from the magnetically-operated switch 19, is referred to as the second state. The magnetically-operated switch 19 generates in the first state a first current and in the second state a second current that is different to the first current. The magnetically-operated switch 19 can be embodied particularly preferably in such a manner that if the switching device 100 is switched off, the first current is less than the second current if the switching device 100 is switched on. For example, the first current can be in the range of 5 to 7 mA and the second current can be in the range of 12 to 17 mA.

[0047] By virtue of detecting the state of the magnetically-operated switch 19, in other words for example as a result of a current measurement at the output of the magnetically-operated switch 19, it is consequently possible to directly detect the state of the switching device ma. In particular, it is possible in a simple manner to detect if the switching device wo is still in the active state due to a stuck contactor although the current for the coil that moves the armature 5 has already been switched off and the switching device wo would accordingly have to be in the non-active state.

[0048] As previously mentioned, the switching device wo in accordance with the illustrated exemplary embodiment comprises furthermore a signal processing device 20 that is connected to the magnetically-operated switch 19. The signal processing device 20 can be provided and configured in particular for measuring the current that is generated by the magnetically-operated switch 19. As is illustrated in FIG. 3A, the magnetically-operated switch 19 comprises a terminal 190 with which the magnetically-operated switch 19 is connected to a voltage supply and thus can be put into operation. The signal processing device 20 comprises a measuring resistor 201 that is connected in series to the magnetically-operated switch 19. In particular, this means that the measuring resistor 201 is connected to the output of the magnetically-operated switch 19 with the result that the current that is generated by the magnetically-operated switch flows through the measuring resistor 201. Since the magnetically-operated switch 19 generates a first current or a second current depending upon its state as previously described, the voltage drop at the measuring resistor 201 can assume relative to the magnetically-operated switch 19 accordingly two values depending upon the state of the magnetically-operated switch 19 and consequently upon the position of the permanent magnet. By virtue of measuring the voltage at the measuring resistor 201, which is indicated by the arrow, it is consequently possible to conclude the switched state of the switching device wo.

[0049] FIG. 3B illustrates a further development of the signal processing device 20 in accordance with a further exemplary embodiment. In comparison to the previous exemplary embodiment, the signal processing device 20 comprises in a branch parallel to the measuring branch that is formed by means of the magnetically-operated switch 19 and the measuring resistor 201 that is connected thereto in a reference branch a Zener diode 202 that can be connected via a terminal 200 to a voltage supply, said Zener diode generating a reference voltage. A comparator 203 that can be an operational amplifier and can be connected via a further terminal 200 to a voltage supply compares the voltage drop at the measuring resistor 201 with the voltage drop at the Zener diode 202. As illustrated, it can be advantageous if the Zener diode 202 is connected via a resistor 204 to the voltage supply. In particular, the comparator 203 comprises two inputs 2031 and 2032 and the prescribed voltages of the measuring branch and the reference branch are present at said inputs. By virtue of the illustrated arrangement, it is possible to realize that the circuit comprising a magnetically-operated switch 19 and signal processing device 20 operates with an arbitrary supply voltage in a wide range. In particular, the magnetically-operated switch 19, the Zener diode 202 and the comparator 203 can be connected to a common supply voltage via the terminals 190, 200. The supply voltage can preferably provide a voltage that is greater than or equal to 3 V and less than or equal to 24 V. For example, it is possible for the voltage that is provided by the voltage supply to be a vehicle electrical system voltage of a motor vehicle that can be 12 V or 24 V.

[0050] The comparator 203 comprises an output 2033, which in dependence upon the voltage at the measuring resistor 201 can assume the as described two values in accordance with the states of the magnetically-operated switch 19, can in comparison to the reference voltage at the Zener diode 202 accordingly adopt two different states. Furthermore, the signal processing device comprises an electronic switch 207 having a control input that is connected to the output 2033 of the comparator 203. It is particularly preferred that the electronic switch 207 can be as illustrated a field effect transistor that is preferably connected to the output of the comparator 203 via a voltage divider that is formed by means of resistors 205, 206. The voltage divider is embodied in such a manner that an unambiguous high and low signal is generated for the control input of the electronic switch 207.

[0051] The components of the signal processing device 20 are configured together with the magnetically-operated switch 19 in particular in such a manner that the electronic switch 207 is in an open state, in other words in a blocking state or a state in which it exhibits at least a high resistance, if the switching device is in the non-active switched state, and said electronic switch is in a closed state, in other words conducting state or at state in which it exhibits at least a low resistance, if the switching device is in the active switched state. In short, the electronic switch 207 that is embodied as a field effect transistor consequently exhibits a low resistance if the permanent magnet moves away from the magnetically-operated switch, and it exhibits a high resistance if the permanent magnet moves sufficiently close to the magnetically-operated switch with the result that the electronic switch 207 demonstrates the same behavior as the switching device 100. In particular, the electronic switch 207 behaves in the same manner as a reed switch but without requiring mechanical parts which are necessary in the case of the reed switch.

[0052] As illustrated in FIG.3C, the electronic switch 207 can be connected for example in such a manner that it is possible depending upon the switched state to generate by means of a terminal 208 an output voltage at a voltage source between the terminals 209 or also an output voltage is not present since in the blocking state there is no terminal to ground with the result that the state of the electronic switch 207 can be detected.

[0053] The features and exemplary embodiments described in conjunction with the FIGS. 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 FIGS. may alternatively or additionally include further features in accordance with the description in the general part.

[0054] 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.