EP2786389B1 - Permanent magnet assembly for an arc driver assembly and switching device - Google Patents

Description

The invention relates to a permanent magnet arrangement for an arc runner arrangement of an electrical switching device with a permanent magnet and a cover made of electrically insulating material. The invention further relates to a switching device for DC application with at least one current path, at least one switching contact arrangement for interrupting the current path, wherein the switching contact arrangement is arranged in a switching chamber of a housing of the switching device, and with an arc runner arrangement, which is arranged in the switching chamber and at least in the region Switching contact arrangement of the respective current path generates a magnetic field.

Permanent magnet arrangements and switching devices of the type mentioned are from the EP 2 061 053 A2 known. To provide a switching device for DC applications there is proposed to use the housing of a switching device for AC applications, in addition permanent magnets are provided which have a magnetic field with substantially transverse to a separation path of the current paths field lines. In the housing, three receiving areas are provided for each one flow path, wherein each current path is associated with a movable switching contact element and two opposing fixed switching contact elements. The three movable switching contact elements are in this case jointly movable between a closed position, which corresponds to the switched-on state of the switching device, and an open position, which corresponds to the switched-off state switching device. The individual current paths are each associated with two arc quenching devices, which are each in the form of individual stacked, electrically insulated from each other quenching plates are formed. In addition, each current path has two separating sections which, when the movable switching contact elements are open, extend between the two Form ends and the first and second fixed switching contact elements associated with these ends. When the switching contact elements are opened, an arc forms along the separating sections, which arc can be extinguished with the aid of one of the arc-extinguishing devices. In DC applications, since erasure of an arc can not be achieved due to current zero crossing, as in AC applications, DC applications require the provision of a magnetic field which drives the arc into one of the arc quenching devices. This magnetic field is formed per current path by two permanent magnet arrangements, whereby a magnetic field is established with field lines in an orientation which run transversely to the separation paths and generate a Lorenz force on arcs along these separation paths which drives the arcs in the direction of the arc extinguishing devices. The arc quenching devices each comprise two permanent magnet arrangements. These each include a permanent magnet and a receiving space in the housing of the switching device. The receiving spaces are assigned to the separating sections and arranged on both sides of these separating sections so that they receive them between them. In the receiving spaces, the permanent magnets are inserted and recorded. Here, the permanent magnets are almost completely enclosed by the walls of the receiving spaces and received by this electrically isolated. Only a part of the permanent magnets is above an opening of the receiving space. At high currents there is thus the danger that an arc will strike the permanent magnets. Another example of a switch apparatus with a permanent magnet arc runner assembly is shown in FIG DE-A-10132858 disclosed. Object of the present invention is to provide a permanent magnet arrangement, in which a rollover of an arc on the permanent magnet and thus a burn of the permanent magnet is prevented as possible.

The object is achieved by a switching device according to claim 1. Thus, it is possible to provide that part of a permanent magnet directly with a cover which protrudes from a receiving chamber for the permanent magnet, so that a rollover of the arc is prevented on this protruding part of the permanent magnet. In the recorded in the receiving chamber state of the permanent magnet is thus completely electrically isolated. It is also advantageous that the permanent magnet can be provided with the cover before insertion into the receiving chamber and can be provided as a prefabricated unit. In this case, the cover detachable or insoluble, z. B. cohesively, be connected to the permanent magnet.

The arc driver assembly may be designed differently. For example, it can be provided that two permanent magnet arrangements are provided, as explained above, between which the switch contact arrangement is arranged. However, it is also conceivable that only one permanent magnet arrangement is provided, which is connected to two parallel pole plates, wherein the permanent magnet is arranged above the switching contact arrangement and the pole plates receive the switching contact arrangement between them.

In an embodiment, the permanent magnet arrangement can be accommodated in a receiving chamber of the housing of the switching device and protrude exclusively with the cover from the receiving chamber. Thus, the housing forms part of the electrical insulation. The protruding from the receiving chamber part of the permanent magnet is electrically insulated by the cover, so that an arc of an arc on the permanent magnet is prevented.

The receiving chamber may in this case be introduced into a wall of the housing.

Preferably, the wall is made of an electrically insulating and magnetically permeable material, for example of a thermoset or temperature-resistant thermoplastic or ceramic. From the same material and the cover can be made.

The permanent magnet arrangement can have a coding projection, which is provided, for example, on the permanent magnet, with which the permanent magnet arrangement dips into a coding recess of the receiving chamber. Thus, it can be ensured that the permanent magnet is basically inserted in the correct magnetic orientation into the receiving chamber to ensure that an arc in the right direction, i. H. into a fire extinguishing device. In the event that the permanent magnet or the permanent magnet assembly is inserted in the wrong direction in the receiving chamber, the receiving chamber is designed such that the Kodiervorsprung can not dip into the Kodierausnehmung and the permanent magnet assembly further protrudes from the receiving chamber, as is the case, when the permanent magnet assembly is correctly inserted. Thus, a direct visual verification of the correct fit of the permanent magnet assembly is possible. Furthermore, it can be provided that z. B. a cover or other components of the switching device can not be mounted when the permanent magnet assembly is inserted incorrectly by the other components abut against the permanent magnet assembly and prevents mounting of the other components.

Figur 1

einen Längsschnitt durch ein erfindungsgemäßes Schaltgerät;

Figur 2

eine Draufsicht in das Schaltgerät gemäß Figur 1;

Figur 3

eine Explosionsdarstellung einer erfindungsgemäßen Permanentmagnetanordnung und

Figur 4

einen Längsschnitt der Abdeckung der Permanentmagnetanordnung gemäß Figur 3.

A preferred embodiment is explained below with reference to the drawings. Herein shows

FIG. 1

a longitudinal section through an inventive switching device;

FIG. 2

a plan view in the switching device according to FIG. 1 ;

FIG. 3

an exploded view of a permanent magnet arrangement according to the invention and

FIG. 4

a longitudinal section of the cover of the permanent magnet assembly according to FIG. 3 ,

FIG. 1 shows the switching device 1 according to the invention in a partial longitudinal section with a housing 2, which comprises a lower part 3 and an upper part 4. FIG. 2 shows a view into the switching device 1, wherein the upper part 4 is omitted so that you can look into the lower part 3. The two Figures 1 and 2 will be described together below.

The switching device 1 has three poles, d. H. three switching paths, namely a first switching path 5, a second switching path 6 and a third switching path 7. Each switching path 5, 6, 7 is arranged in a separate switching chamber, namely a first switching chamber 8, a second switching chamber 9 and a third switching chamber 10. The switching chambers 8, 9, 10 are electrically separated from each other by partitions 11, 12 of the housing 2, wherein the intermediate walls 11, 12 are preferably magnetically permeable. The three current paths 5, 6, 7 are identical in terms of their structure, wherein the structure of the current paths 5, 6, 7 is explained in more detail by way of example with reference to the middle second current path 6 in the following.

The second flow path 6 within the second switching chamber 9 is in FIG. 1 shown in longitudinal section. The second switching path 6 is formed twice interrupting and has a first switching contact arrangement 13 and a second switching contact arrangement 16. The two switch contact arrangements 13, 16 are identical and mirror images of each other.

The first switching contact arrangement 13, which in FIG. 1 is shown on the left side, comprises a contact pair with a first contact 14 and a second contact 15. Accordingly, the second switching contact arrangement 16 with a second contact pair comprising a first contact 17 and a second contact 18 is formed.

The first contact 14 of the first switching contact arrangement 13 is arranged on a first fixed contact carrier 19. The first fixed contact carrier 19 is fixed and thus arranged immovably in the housing 2 of the switching device 1. The first contact 14 is arranged at a first free end of the first fixed contact carrier 19. At a this end facing away from the end of the first fixed contact carrier 19, a first terminal 23 is provided for the connection of the first current path 5 in a DC circuit.

The second contact 15 of the first switch contact arrangement 13 is located on a bridge contact piece 20 of a bridge arrangement 21 and is movably arranged in the housing 2. The bridge contact piece 20 is in the in FIG. 1 Oriented orientation vertically adjustable between a raised and a lowered position. In the raised position, the second contact 15 of the first switch contact arrangement 13 is in contact with the first contact 14. In a lowered position, the two contacts 14, 15 are out of contact. In this position, an isolating distance is formed between the first contact 14 and the second contact 15, along which an arc can form.

The second switching contact arrangement 16 is identical to the first switching contact arrangement 13. The first contact 17 of the second switching contact arrangement 16 is located on a second fixed contact carrier 22 and is arranged at a first end of the second fixed contact carrier 22. At a this end remote from the end of the second fixed contact carrier 22, a second terminal 24 is provided.

The second contact 18 of the second switching contact arrangement 16 is likewise arranged on the bridge contact piece 20, specifically on an end remote from the second contact 15 of the first switching contact arrangement 13. The bridge switching piece 20 is electrically conductive and connects the two second contacts 15, 18 electrically to each other. In the raised state of the bridge switching piece 20, the second contact 18 of the second switching arrangement 16 is in contact with the first contact 17, wherein in the lowered position of the bridge switching piece 20, the two contacts 17, 18 are kept out of contact and forms an insulating gap between them, along which can also form an arc.

In the raised state of the bridge switching element 20, a current can thus flow from the first terminal 23 via the first fixed contact carrier 19 to the first contact of the first switching contact arrangement 13, then on to the second contact 15 of the first switching contact arrangement 13 via the bridge contact piece 20 to the second contact 18 of the second switching contact arrangement 16 , From there, the current continues to flow to the first contact 17 of the second switching contact arrangement 16 via the second fixed contact carrier 22 to the second connection 24.

For adjusting the bridge switching piece 20, a switching bridge 30 is provided, which is arranged vertically displaceable in the housing 2 and the bridge switching piece 20 adjusted. In the raised state of the bridge switching piece 20, which corresponds to the switched state of the switching device 1, the bridge switching piece 20 is pressed with its second contacts 15, 18 via a spring 31 against the first contacts 14, 17, wherein the spring 31 between the bridge contact piece 20 and the switching bridge 30 is supported.

In the second switching chamber 9, two erasing devices, namely a first erasing device 27 and a second erasing device 28 are provided. The first erasing device 27 is assigned to the first switching contact arrangement 13 and the second erasing device 28 to the second switching contact arrangement 16. The two erasing devices 27, 28 are each arranged on a side of the respective switching contact arrangement 13, 16 facing away from the switching bridge arrangement 21.

In order to drive resulting arcs between the contact pairs in the quenching devices 27, 28, 9 two arc runner arrangements are provided in the second switching chamber, namely a first Arc runner assembly 32 and a second arc runner assembly 33, wherein the first arc runner assembly 32 of the first switch contact arrangement 13 and the second arc runner assembly 33 of the second switch contact arrangement 16 is associated. The first arc runner arrangement 32 comprises two first permanent magnet arrangements 25, which are arranged in the second switching chamber 9 and receive the first switching contact arrangement 13 between them. The first permanent magnet arrangements 25 are arranged parallel to the intermediate walls 11, 12. The two first permanent magnets 25 are arranged rectified with respect to their magnetization, so that forms an approximately homogeneous magnetic field with field lines transverse to the separation direction between them. Thus, the field lines of the magnetic field also extend transversely to an arc, which forms between the first contact 14 and the second contact 15 of the first switching contact arrangement 13. As a result, a Lorenz force is generated by the magnetic field, which acts on the arc and drives it in the direction of the first extinguishing device 27.

The second arc driver assembly 33 is constructed similar to the first arc driver assembly 32 and includes two second permanent magnet assemblies 26 sandwiching the second switch contact assembly 16. The magnetic field may be aligned in the same direction as that of the first permanent magnet arrangements 25. An arc, which is formed between the first contact 17 and the second contact 18 of the second switching contact arrangement 16, has a current direction, which is spatially opposite to the current direction of an arc between the contacts 14, 15 of the first switching contact arrangement 13. If an arc as shown in FIG. 1 between the contacts 17, 18 of the second switching contact arrangement 16 has a current direction vertically downward, an arc between the contacts 14, 15 of the first switching contact arrangement, a current direction vertically upwards. In order to drive an arc on the first switching contact arrangement 13 to the left and an arc on the second switching contact arrangement 16 to the right in the second quenching device 28, therefore, the magnetic fields must be aligned in the same direction. In such an orientation, however, the switching device 1 is only suitable for one current direction, because it is not able to drive the arcs in the quenching devices in another current direction. In order to achieve independence from the current direction, the magnetic fields of the two arc drive assemblies 32, 33 may be oppositely oriented, so that in one direction of the first arc, the arc at the first switching contact arrangement 13 and in a second direction opposite to the first current direction, the arc at the second Switching contact arrangement 16 is deleted.

The first flow path 5 and the third flow path 7 as well as the first switching chamber 8 and the third switching chamber 10 are identical to the second flow path 6 and the second switching chamber 9, but with the difference that in the first switching chamber 8 and the third switching chamber 10 no arc drive arrangements are arranged. In the first switching chamber 8 and in the third switching chamber 10 thus no permanent magnet arrays are arranged. The arc runner arrangements 32, 33 of the first current path 6 radiate to the adjacent switching chambers, namely the first switching chamber 8 and the third switching chamber 10, in order to be able to exert a Lorentz force on a developing arc there as well. In principle, however, the first switching chamber 8 and / or the third switching chamber 10 may be provided with arc bus driver arrangements.

In the FIGS. 3 and 4 the first permanent magnet arrangement 25 is shown in detail. The remaining permanent magnet arrangements are constructed identically. The first permanent magnet arrangement 25 comprises a permanent magnet 34, which is designed plate-shaped. At one end of the permanent magnet 34, which in the illustration according to FIG. 1 is the upper end, a cover 35 made of an electrically insulating material is attached directly to the permanent magnet 34. For this purpose, the permanent magnet 34 fastening projections 36, which dip into a mounting recess 37 of the cover 35. The cover 35 may be releasably connected to the permanent magnet 34 via adhesion or firmly via material bond, for example via a bond.

Out FIG. 2 shows that in the switching chambers 8, 9, 10 receiving chambers 38 are provided. As an example, a receiving chamber 38 in the second switching chamber 9 is explained in more detail below. The receiving chamber 38 is disposed on one of the intermediate walls 11, wherein the intermediate wall 11 also simultaneously represents a wall of the receiving chamber 38. Further, the receiving chamber 38 comprises a parallel to the intermediate wall 11 extending inner wall 39 and the intermediate wall 11 and the inner wall 39 connecting side walls 40, 41, so that in FIG. 1 upwardly open receiving chamber 38 is formed. This is also closed at the bottom by a bottom wall 42 of the housing 2. The permanent magnet 34 with attached cover 35 is inserted into the receiving chamber 38 from above, with only the cover 35 from the receiving chamber 38 projects upwards. Since all walls 12, 39, 40, 41 of the receiving chamber 38 are made of an electrically insulating material, skipping an arc on the permanent magnet 34 is effectively prevented.

On a side facing away from the cover 35, the permanent magnet 34 has a coding projection 44, with which this dips into a Kodierausnehmung 43 of the receiving chamber 38. Since the coding projection 44 and the coding recess 43 are arranged laterally offset from an axis of symmetry, the permanent magnet 34 can be used only in one of its magnetic orientations. This avoids that a wrong magnetic field is built up.

Furthermore, the cover 35 has upwardly facing stop projections 45. When the permanent magnet 34 is inserted into the receiving chamber 38 in the wrong direction, the coding projection 44 can not be immersed in the coding recess 43, so that the permanent magnet 34 protrudes farther from the receiving chamber 38 than when properly inserted. In this incorrectly inserted position, the fixed contact carrier 19 can not be mounted, since this abuts against the stop projections 45. A wrong assembly is thus safely avoided.

LIST OF REFERENCE NUMBERS

1

switchgear

2

casing

3

lower part

4

top

5

first current path

6

second current path

7

third current path

8th

first switching chamber

9

second switching chamber

10

third switching chamber

11

partition

12

partition

13

first switching contact arrangement

14

first contact

15

second contact

16

second switch contact arrangement

17

first contact

18

second contact

19

first fixed contact carrier

20

Bridging contact member

21

bridge arrangement

22

second fixed contact carrier

23

first connection

24

second connection

25

first permanent magnet arrangements

26

second permanent magnet arrangements

27

first extinguishing device

28

second extinguishing device

29

splitter

30

jumper

31

feather

32

first arc driver assembly

33

second arc driver assembly

34

permanent magnet

35

cover

36

fixing projection

37

mounting recess

38

receiving chamber

39

inner wall

40

Side wall

41

Side wall

42

bottom wall

43

coding aperture

44

coding projection

45

stop projection

Claims (6)

1. Switching device for direct current applications, comprising
   at least one current path (5, 6, 7),
   at least one switching contact arrangement (13, 16) for interrupting the at least one current path (5, 6, 7), wherein the switching contact arrangement (13, 16) is arranged in a switching chamber (8, 9, 10) of a housing (2) of the switching device (1), and
   an arc driver arrangement (32, 33) which is arranged in the switching chamber (8, 9, 10) and generates a magnetic field at least in the region of the switching contact arrangement (13, 16) of the respective current path (5, 6, 7),
   wherein the arc driver arrangement (32, 33) includes at least one permanent magnet arrangement (25, 26) having a permanent magnet (34) and a cover (35) made from electrically insulating material, characterised in that the cover (35) is directly fastened to one end of the permanent magnet (34), wherein the permanent magnet arrangement (25, 26) is received in a receiving chamber (38) of the housing (2) and projects exclusively with the cover (35) out of this housing.
2. Switching device according to claim 1, characterised in that the arc driver arrangement (32, 33) comprises two permanent magnet arrangements (25, 26), between which the switching contact arrangement (13, 16) is arranged.
3. Switching device according to one of the preceding claims, characterised in that the receiving chamber (38) is introduced into a wall (11, 12) of the housing (1).
4. Switching device according to claim 3, characterised in that the wall (11, 12) is made from an electrically insulating and magnetically permeable material.
5. Switching device according to one of the preceding claims, characterised in that the permanent magnet arrangement (25, 26) has a coding projection (44) by which the permanent magnet arrangement (25, 26) penetrates into a coding recess (43) of the receiving chamber (38).
6. Switching device according to one of the preceding claims, characterised in that the cover (35) is made from an electrically insulating and magnetically permeable material.

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