EP2590192A1 - Switch for multi-pole direct current operation - Google Patents

Abstract

The switch has movable switching bridge (35) that is arranged extending switching chambers. The switching chambers comprise bridge contact (30) and bridge contact elements are spaced apart from each other along the main direction of the switching bridge. The main direction of the switching bridge is perpendicular aligned to the axis of movement of the switching bridge.

Description

The invention relates to a multi-pole switch, which is provided in particular for a DC operation, with a partial switching chamber per pole.

Electrical switches are components in a circuit that establish or disconnect an electrically conductive connection by means of internal, electrically conductive contacts. With a live connection to be cut, current flows through the contacts until they are separated. When an inductive circuit is disconnected by a switch, the current flow does not reduce immediately to zero, so that an arc can form between the contacts. The arc is a gas discharge by a per se non-conductive medium, such as air. In alternating current (AC) switches, arcs usually erase at the zero crossing of the alternating current. Since such a zero crossing of the current in switches with DC operation (DC) is missing, stable arcing can occur when disconnecting the contacts. If the circuit is operated with sufficient current and voltage, for example, more than about one ampere and more than 50 volts, the arc does not automatically go out. For this reason, in such switches extinguishing chambers are known which serve to extinguish the arc. The period during which the arc burns should be kept as short as possible, since the arc releases a large amount of heat, which leads to the burning of the contacts and / or the thermal load of the switching chamber in the switch and thus reduces the life of the switch. In two-pole or multi-pole switches with two or more switching chambers correspondingly higher amounts of heat are released by arcing than in single-pole switches. Therefore, there is a particular need to quickly extinguish the arcs.

It is also known to accelerate the extinction of the arc by the use of a magnetic field that is poled so that it exerts a driving force on the arc in the direction of the quenching chambers. To generate a strong magnetic field usually permanent magnets are used. The driving force of the magnetic field in the direction of the quenching chambers is only at a certain current flow direction given. Polarity-related installation errors of switches are avoided by switches for both current directions, which have an independent of the respective polarity erasing behavior for arcs. Such a switch is for example in the document EP 2 061 053 A2 described.

If a multi-pole switch is to be equipped accordingly, especially in a non-polarity extinguishing behavior, additional switching chambers for each pole are necessary. As a result, multipole switches can reach a size for which insufficient space, in particular not sufficient depth, is available in common control cabinets, for example.

An object of the invention is to provide a multi-pole switch available whose space requirements, at least in depth, based on the installation situation in a cabinet, compared to single-ended switches is not or not much higher.

The object is achieved by the switch according to claim 1. In the dependent claims preferred embodiments and advantageous developments are given.

The switch according to the invention is intended for multi-pole operation, in particular direct current operation, with a switching chamber, wherein a partial switching chamber is provided for each pole. The switching chamber has a movable switching bridge extending through both sub-switching chambers, wherein a bridge switching piece is provided for each sub-switching chamber in the switching bridge and the bridge switching pieces are arranged at a distance from one another along a main extension direction of the switching bridge. The main extension direction of the switching bridge is aligned according to the invention substantially perpendicular to a movement axis of the switching bridge. Expressed in terms of installation depth in a control cabinet or a comparable device with a limited installation depth, the bridge contact pieces are advantageously arranged side by side substantially in a plane. The main extension direction of the switching bridge is that direction in which the switching bridge has its greatest extent, namely in the plane of the bridge contact pieces. Each of the sub-switching chambers accordingly has two fixed contact pieces, which are arranged in a plane parallel to the plane of the bridge contact pieces and which by the perpendicular to the Main extension direction of the bridge bridge movable bridge switching pieces synchronized electrically connected and disconnected.

The sub-switching chambers are arranged and formed mirror-symmetrical in particular in one plane. Against the action of arcs of the pole of the other part switching chamber, the sub-switching chambers are preferably electrically sealed off.

According to a preferred embodiment, it is provided that each partial switching chamber has two switching pieces with a first contact region per switching piece, wherein the switch bridge movable and electrically conductive bridge switching pieces each have two second contact areas for producing an electrically conductive connection between the first and second contact areas and for separating the have first and second contact areas. This results in a multi-pole switch with double interruption per pole. Alternatively, a contact pair of first and second contact region per pole could be inseparable, for example, connected by a stranded wire, so that a single interruption can be realized.

According to a further preferred embodiment it is provided that the bridge switching pieces extend substantially perpendicular to the main extension direction of the switching bridge, wherein the fixed contact pieces extend parallel to the main extension direction of the switching bridge.

For at least one of the partial switching chambers, at least two extinguishing devices are provided for extinguishing arcs, which can occur when the first and second contact regions are disconnected. In order to ensure a polarity-independent DC operation, it is provided that four extinguishing devices for polarity-independent extinguishment of arcs, which may occur during separation of the first and second contact areas, are provided for at least one of the partial switching chambers.

According to a further preferred embodiment, it is provided that first arc conductors extend from the first contact regions and second arc conductors extend from the second contact regions toward the extinguishing devices. This advantageously prevents an arc from occurring along the Bridge switching pieces moved in the direction of the switching bridge. A distance of the first arc conductors from the second arc conductors preferably increases in the direction of the extinguishing devices, whereby the respective arc is advantageously stretched on the way to the extinguishing device.

Preferably, a permanent magnet arrangement is provided to form in the areas between the first and second contact areas and the respective extinguishing devices a substantially homogeneous magnetic field for exerting a magnetic force on the arcs, so that at least one of the arcs, regardless of the current direction in the arc in the direction of one of Extinguishing devices is driven. The permanent magnet arrangement has at least two plate-shaped magnets, wherein the magnets are arranged on longitudinal sides of the partial switching chambers, in each case adjacent to the contact areas.

According to a further preferred embodiment, it is provided that the permanent magnet arrangement has two parallel pole plates, the pole plates being connected to one another by one or more permanent magnets to form a substantially U-shaped profile, whereby a particularly homogeneous magnetic field of high magnetic field strength can be built up.

The invention will be explained in more detail with reference to an embodiment with reference to the drawings. The embodiments are merely exemplary and do not limit the general inventive concept.

• Figuren 1 und 2 eine Ausführungsform des erfindungsgemäßen Schalters in verschiedenen Darstellungen;
• Figur 3 eine weitere Ausführungsform des erfindungsgemäßen Schalters;
• Figur 4 eine Schaltbrücke für eine der Ausführungsformen des erfindungsgemäßen Schalters;
• Figur 5 eine Magnetanordnung für eine der Ausführungsformen des erfindungsgemäßen Schalters.

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• FIGS. 1 and 2 an embodiment of the switch according to the invention in various representations;
• FIG. 3 a further embodiment of the switch according to the invention;
• FIG. 4 a switching bridge for one of the embodiments of the switch according to the invention;
• FIG. 5 a magnet arrangement for one of the embodiments of the switch according to the invention.

The embodiment of the invention according to the FIGS. 1 and 2 shows a multi-pole, independent of the current direction compact switch with efficient erase behavior. In this case, a double-break contact system is realized for each pole, in which each of the switching arcs arising when opening the contacts is always moved in the direction of an arc extinguishing device 61 regardless of the current direction using permanent magnetic blower. The contact and erase arrangements of both poles are housed here in a single switching chamber. The advantage of such a switch consists on the one hand in a relatively simple, easy to assemble construction, on the other hand in a switch of comparatively small installation depth. The embodiment will be described with reference to FIGS FIGS. 1 and 2 described.

The switching chamber of the two-pole switch is subdivided in its main extension direction into two equally partitioned partial switching chambers 1, 2 or segments 1, 2 which are sealed off from one another and in which the contact and extinguishing arrangements of one pole each are accommodated. As the only spatial connection between the two switching chamber halves 1, 2 extends centrally in the main extension direction of the switching chamber, a channel 3, which surrounds the switching bridge 35, in each of which a bridge bridge contact piece 30 is installed. The two bridge switching pieces 30 have the same installation depth and are arranged in a region of the center of the respective sub-switching chamber 1, 2, wherein the bridge switching pieces 30 extend in a direction which is rotated by 90 degrees against the main extension direction of the switching chamber. The bridge switching pieces 30 have second contact areas 31 or contact pads 31 for making contact with first contact areas 11 or fixed contacts 11. From the second contact portions 31 at right angles outgoing skid-shaped legs each extend in the direction of a connecting axis of two opposing extinguishing devices 61 and are angled in such a way that second arc conductors 32 are formed whose dropouts in the off state of the switch respectively in the direction of an upper edge 65 of the extinguishing devices 61 show. The fixed contact pieces 20a, 20b of the partial switching chamber 2 enter on the short side or head side of the switching chamber in this. In the area of the fixed contacts 11, the contact pieces 20a, 20b are angled or cranked, whereby first arc conductors 12 are made available. The fixed contacts 11 are arranged in an installation depth which corresponds approximately to the center of the extinguishing chambers 61. With closed contacts 11, 31 form the parallel switching pieces 20a, 20b together with the transverse thereto bridge switching piece 30 has a U-shaped current path. Due to the geometry of the contact pieces 20a, 20b with the first contact areas 11 and the bridge contact pieces 30 with the second contact areas 31, an arc runner arrangement is formed from the first arc conductors 12 and the second arc conductors 32, which widens in the direction toward the quenching chambers 61, so that a switching arc arising when the contacts are opened, that is to say when the second contact regions 31 are separated from the first contact regions 11, is rapidly moved in the direction of one of the extinguishing devices 61 under the influence of a magnetic blowing action and thereby continuously expands. The part switching chamber 1 with the switching pieces 10 a, 10 b is carried out analogously to the previously described part switching chamber 2.

The extinguishing devices 61 are executed in the illustrated embodiment as so-called Deion chambers, which consist of a stack arrangement of mutually electrically insulated sheets, each with an air gap between two adjacent sheets. Each pair of contacts, consisting of a first contact region 11 and a second contact region 31, two of the extinguishing chambers 61 are assigned, which are housed in the main extension direction of the switch in oppositely disposed niches. Each pole has, in a double interrupting contact arrangement, two pairs of opposite extinguishing chambers 61, which are arranged symmetrically on both sides of the switching bridge 35. The described contact and erase arrangements of both poles are preferably arranged axially symmetrically on both sides of a central axis in the main extension direction of the switching chamber.

The structure of the magnetic blowing field in accordance with the illustrated embodiment FIGS. 1 and 2 realized via a permanent magnetic arrangement. This consists of two plate-shaped magnets 51 for each pole, which are arranged on the longer switching chamber wall in the region of the contact pairs 11, 31. In this case, the plate-shaped magnets Be arranged outside of the chamber wall or inside, for example, in accordance with insulating pockets of the inside niche walls. A switching arc arising when the contacts are opened is moved in the direction of one or the other of the two opposing extinguishing devices 61, due to the so-called magnetic blowing effect, caused by the Lorentz force, depending on the current direction. The permanent magnets are preferably made either of ferritic material or of a material with rare earth contents, for example Nd-Fe-B or Sa-Co, or of materials in the form of plastic-bonded molded parts.

In the FIG. 3 schematically another embodiment of the inventive switch is shown, which differs from the embodiment of FIGS. 1 and 2 differs by an alternative extinguishing arrangement without Deion chambers. The extinguishing arrangement is given by a niche arrangement with walls of insulating material, preferably made of thermosetting plastic or ceramic, wherein the individual niches are spatially separated from each other sufficiently and exhaust ports are arranged on the outside walls. In the illustrated embodiment, extending in the main extension direction of the switching chamber niche walls 45 made of plastic, while the transverse thereto bulkheads 46 between the sub-switching chambers 1, 2 of both poles in terms of high thermal resistance to arc exposure of ceramic material.

In the FIG. 4 a switching bridge 35 of a further embodiment of the switch according to the invention is shown, which differs from the embodiment of FIGS. 1 and 2 distinguished by an alternative permanent magnet arrangement. Achieving higher magnetic field strengths in the region of the switching contacts can be achieved by adding a further permanent magnet 51c, preferably by integration in the switching bridge 35 or by attachment to the inside niche walls for the extinguishing devices. The additional magnets 51s may be arranged inside, for example, in correspondingly insulating pockets of the inside niche walls.

In the FIG. 5 a further variant of a permanent magnet arrangement for a further embodiment of the switch according to the invention is shown. An efficient magnetic blowing field of high homogeneity can be achieved by an arrangement of two plane-parallel plates 55 of magnetically good conductive material, preferably of soft magnetic iron, form, which are connected by one or more permanent magnets 51 in such a way that they form an approximately U-shaped profile. The polarity of the magnet 51 is indicated by the data north (N) and south (S). The distance between the parallel pole plates 55 is in this case dimensioned so that they extend in close proximity along the lateral outer walls of the quenching chamber. Recesses 58 are provided for the passage of bridge switching pieces 30. Depending partial switching chamber 1, 2, two axisymmetric arranged permanent magnet arrangements of the type shown are provided. The shield plate 56 serves to magnetically shield the switch from the permanent magnet 51.

LIST OF REFERENCE NUMBERS

1.2

Part interrupters

3

channel

10a, 10b

Fixed contact pieces of the first part switching chamber

20a, 20b

Fixed contact pieces of the second part switching chamber

11

First contact area, fixed contact

12

First arc conductor

30

Bridging contact member

31

Second contact area

32

Second arc conductor

35

jumper

45

niche walls

46

bulkheads

51

magnets

51c

additional magnet

55

pole plates

56

shield

57

permanent magnet

58

recess

61

extinguishing device

65

Top edge of the extinguishing device

Claims (14)

Switch for multi-pole operation with a switching chamber, wherein each Pol a Teilschaltkammer (1, 2) is provided, characterized in that the switching chamber by a two switching chambers (1, 2) extending, movable switching bridge (35), wherein in the switching bridge in each case one bridge contact piece (30) is provided for each partial switching chamber (1, 2) and the bridge switching pieces are arranged spaced apart from one another along a main extension direction of the switching bridge (35) and wherein the main extension direction of the switching bridge (35) is substantially perpendicular to a movement axis of the switching bridge (35 ) is aligned. Switch according to claim 1, characterized in that the sub-switching chambers (1, 2) are arranged mirror-symmetrically to each other. Switch according to one of the preceding claims, characterized in that the sub-switching chambers (1, 2) are electrically sealed off against the action of arcs of the pole of the respective other sub-switching chamber. Switch according to one of the preceding claims, characterized in that each partial switching chamber (1, 2) has two fixed contact pieces (10a, 10b, 20a, 20b) with a first contact region (11) per contact piece, wherein the movable with the switching bridge (35) and electrically conductive bridge switching pieces (30) each having two second contact regions (31) for producing an electrically conductive connection between the first and second contact regions (11, 31) and for separating the first and second contact regions (11, 31). Switch according to one of the preceding claims, characterized in that the bridge switching pieces (30) extend substantially at right angles to the main extension direction of the switching bridge (35), wherein fixed contact pieces (10a, 10b, 20a, 20b) extend parallel to the main extension direction of the switching bridge , Switch according to one of the preceding claims, characterized in that for at least one of the partial switching chambers (1, 2) at least two extinguishing devices (61) for extinguishing arcs, which can occur during separation of the first and second contact regions (11, 31) are provided , Switch according to one of the preceding claims, characterized in that four extinguishing devices (61) are provided for at least one of the partial switch chambers (1, 2) for polarity-independent extinguishing of arcs, which can occur during separation of the first and second contact regions (11, 31) , Switch according to one of Claims 6 or 7, characterized in that first arc conductors (12) extend from the first contact regions (11) and second arc conductors (32) extend from the second contact regions (31) towards the extinguishing devices (61, 62 ). Switch according to claim 8, characterized in that a distance of the first arc conductor (12) from the second arc conductors (32) increases in the direction of the respective extinguishing devices (61). Switch according to one of the preceding claims, characterized in that a permanent magnet arrangement is provided in order to form a substantially homogeneous magnetic field in the regions between the first and second contact regions (11, 31) and the respective extinguishing devices (61). Switch according to Claim 10, characterized in that the permanent magnet arrangement has at least two plate-shaped magnets (51), the magnets (51) being arranged on longitudinal sides of the partial switching chambers (1, 2), in each case adjacent to the contact regions (11, 31). Switch according to one of claims 10 or 11, characterized in that the permanent magnet arrangement comprises two parallel pole plates (55), wherein the pole plates (55) are interconnected by one or more permanent magnets (57) to a substantially U-shaped profile. Switch according to one of claims 6 to 12, characterized in that the extinguishing devices (61) are designed as Deion chambers, with a stack arrangement of mutually electrically insulated sheets, each with an air gap between two adjacent sheets. Switch according to one of claims 6 to 12, characterized in that the extinguishing devices are formed by a niche arrangement with walls of insulating material, wherein individual niches by niche walls (45) and / or bulkheads (46) are largely sealed off from each other and wherein on an outside wall each exhaust openings are arranged.

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