EP2786389A1

EP2786389A1 - Permanent magnet assembly for an arc driver assembly and switching device

Info

Publication number: EP2786389A1
Application number: EP12794315.7A
Authority: EP
Inventors: Klaus Dauer; Anke Juelich
Original assignee: Eaton Electrical IP GmbH and Co KG
Current assignee: Eaton Electrical IP GmbH and Co KG
Priority date: 2011-11-29
Filing date: 2012-11-28
Publication date: 2014-10-08
Anticipated expiration: 2032-11-28
Also published as: EP2631928A1; US20150048911A1; PL2786389T3; US10290439B2; EP2786389B1; WO2013079511A1

Abstract

The invention relates to a permanent magnet assembly (25, 26) for an arc driver assembly (32, 33) of an electric switching device (1), comprising a permanent magnet (34) and a cover (35) made of electrically insulating material, wherein the cover (35) is connected directly to the permanent magnet (34).

Description

PERMANENT MAGNETIC ARRANGEMENT FOR ONE

LIGHT BAND DRIVER ASSEMBLY AND SWITCHGEAR

The invention relates to a permanent magnet arrangement for a

Lichtbogentreiberanordnung an electrical switching device with a

Permanent magnets and a cover made of electrically insulating material. Furthermore, the invention relates to a switching device for DC application with at least one current path, at least one switching contact arrangement for

Breaking the current path, wherein the switch contact arrangement in a

Switching chamber of a housing of the switching device is arranged, and with a Lichtbogentreiberanordnung which is arranged in the switching chamber and at least in the region of the switching contact arrangement of the respective current path generates a magnetic field.

Permanent magnet arrangements and switching devices of the aforementioned type are known from EP 2 061 053 A2. To create a switching device for

DC applications are proposed there 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 Ends and the ends associated with these first and second fixed

Form switching contact elements. 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. There at

In DC applications, erasure of an arc can not be achieved due to zero current passage, 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 Lorentz force on arcs along these separation sections 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 one

Permanent magnets and a receiving space in the housing of the switching device. The recording rooms are assigned to the separation sections and on both sides of this

Dividing lines arranged so that they absorb these between themselves. 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. 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 permanent magnet arrangement for a

Arc guide assembly of an electrical switching device solved, wherein the

Permanent magnet assembly comprises a permanent magnet and a cover of electrically insulating material, wherein the cover is directly connected to the permanent magnet. Thus, it is possible to provide that part of a permanent magnet directly with a cover, which consists of a receiving chamber for the

Permanent magnet protrudes, so that a flashover of the arc is prevented on this protruding part of the permanent magnet. I'm in the

Recording chamber recorded state, 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 object is further achieved by a switching device for DC applications, which at least one current path, at least one switching contact arrangement for interrupting a current path, wherein the switching contact arrangement in a

Switching chamber of a housing of the switching device is arranged, as well as a

Arc runner assembly, which is arranged in the switching chamber and at least in the region of the switching contact arrangement of the respective current path generates a magnetic field comprises, wherein the arc runner arrangement at least one

Permanent magnet arrangement as explained above comprises.

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 exclusively with the

Cover protruding 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 may have a coding projection, which is provided, for example, on the permanent magnet, with which the

Permanent magnet arrangement is immersed in a Kodierausnehmung 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. in a

Extinguishing device is driven. 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, if the

Permanent magnet assembly is inserted correctly. 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.

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

Figure 1 shows a longitudinal section through an inventive switching device; Figure 2 is a plan view of the switching device of Figure 1;

Figure 3 is an exploded view of an inventive

Permanent magnet arrangement and

4 shows a longitudinal section of the cover of the permanent magnet arrangement according to FIG

FIG. 3.

Figure 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. Figure 2 shows a view into the switching device 1, wherein the upper part 4 is omitted, so that one can look in the lower part 3. The two figures 1 and 2 are described together below. The switching device 1 has three poles, d. H. three switching paths, namely a first

Switching track 5, a second switching path 6 and a third switching path 7. Each switching path 5, 6, 7 is in a separate switching chamber, namely a first

Switching chamber 8, a second switching chamber 9 and a third switching chamber 10 is arranged. 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 in the following the structure of

Current paths 5, 6, 7 is explained in more detail by way of example with reference to the middle second current path 6.

The second flow path 6 within the second switching chamber 9 is shown in Figure 1 in longitudinal section. The second switching path 6 is formed twice interrupting and has a first switching contact arrangement 13 and a second

Switch 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 is shown in Figure 1 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 switching piece 20 is vertically adjustable in the orientation shown in Figure 1 between a raised and a lowered position. In the raised position, the second contact 15 of the first

Switch contact arrangement 13 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 is formed. 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 also on

Bridge switching piece 20 arranged on a side facing away from the second contact 15 of the first switching contact arrangement 13 of the same end. The

Bridge contact piece 20 is electrically conductive and connects the two second contacts 15, 18 electrically to each other. In the raised state of

Bridge contact piece 20 is the second contact 18 of the second switching arrangement 16 in contact with the first contact 17, wherein in the lowered position of

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 terminal 24th

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 the first switching contact arrangement 13 and the second

Erase device 28 of the second switching contact arrangement 16 assigned. 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 are in the second switching chamber 9 two

Lichtbogentreiberanordnungen provided, 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 with respect to their

Magnetization arranged rectified, 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 extending between the first contact 14 and the second contact 15 of the first

Switching contact arrangement 13 forms. 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 similar to the first

Arc runner assembly 32 constructed and includes two second

Permanent magnet assemblies 26 which receive the second switching contact arrangement 16 between them. The magnetic field may be aligned in the same direction as that of the first permanent magnet arrangements 25. An arc extending between the first contact 17 and the second contact 18 of the second

Switch contact arrangement 16 is formed, 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 Figure 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. To make an arc at the first

Switch contact arrangement 13 to the left and an arc at the second

Switching contact assembly 16 to drive to the right in the second erasing 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 the first direction of the current, the arc at the first switching contact arrangement 13 and in one of the first

Current direction opposite second current direction of the arc at the second switching contact assembly 16 is deleted.

The first flow path 5 and the third flow path 7 and 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 is formed, but with the difference that in the first switching chamber 8 and the third switching chamber 10 no

Arc guide assemblies 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 with

Be provided Lichtbogentreiberanordnungen.

In Figures 3 and 4, the first permanent magnet assembly 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 fastened 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. From Figure 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. Furthermore, the receiving chamber 38 comprises a parallel to the intermediate wall 11 extending inner wall 39 and the

Partial wall 11 and the inner wall 39 connecting side walls 40, 41, so that in Figure 1 upwardly open receiving chamber 38 is formed. This is also closed at the bottom by a bottom wall 42 of the housing 2. Of 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 Kodiervor jump 44, with which this in a Kodierausnehmung 43 of

Accommodating chamber 38 dips. 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 switching device

2 housings

3 lower part

4 shell

5 first current path

6 second current path

7 third current path

8 first switching chamber

9 second switching chamber

10 third switching chamber

11 intermediate wall

12 intermediate wall

13 first switching contact arrangement

14 first contact

15 second contact

16 second switching contact arrangement

17 first contact

18 second contact

19 first fixed contact carrier

20 bridge contact

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 plate

30 switching bridge

31 spring first arc runner arrangement second arc runner arrangement

permanent magnet

cover

fixing projection

mounting recess

receiving chamber

inner wall

Side wall

bottom wall

Coding recess

This is the first step

stop projection

Claims

claims

1. permanent magnet arrangement (25, 26) for a

Arc guide assembly (32, 33) of an electrical switching device (1) with a permanent magnet (34) and a cover (35) of electrically insulating material, characterized in that the cover (35) is directly connected to the permanent magnet (34).

2. Permanent magnet arrangement according to claim 1, characterized

characterized in that the cover (35) is made of an electrically insulating and magnetically permeable material.

3. comprising switching device for DC applications

at least one flow 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) in a switching chamber (8, 9, 10) of a housing (2) of the switching device (1) is arranged, and a Lichtbogentreiberanordnung (32, 33) which is arranged in the switching chamber (8, 9, 10) and at least in the region of the switching contact arrangement (13, 16) of the respective current path (5, 6, 7) generates a magnetic field, characterized in that the arc runner assembly (32, 33) comprises at least one permanent magnet assembly (25, 26) according to claim 1.

4. Switching device according to claim 3, characterized in that the arc runner arrangement (32, 33) comprises two permanent magnet arrangements (25, 26) according to claim 1, between which the switching contact arrangement (13, 16) is arranged.

5. Switching device according to one of claims 3 or 4, characterized

characterized in that the permanent magnet arrangement (25, 26) in one

Receiving chamber (38) of the housing (1) is received and only with the cover (35) protruding therefrom.

6. Switching device according to claim 5, characterized in that the

Receiving chamber (38) in a wall (11, 12) of the housing (1) is introduced.

7. Switching device according to claim 6, characterized in that the wall (11, 12) is made of an electrically insulating and magnetically permeable material.

8. Switching device according to one of claims 5 to 7, characterized

in that the permanent magnet arrangement (25, 26) has a coding projection (44), with which the permanent magnet arrangement (25, 26) is inserted into a

Coding recess (43) of the receiving chamber (38) is immersed.