EP2783379B1 - Switch for direct current operation with at least one switching chamber - Google Patents

Description

The invention relates to a switch, which is provided in particular for a DC operation, comprising at least one switching chamber, each switching chamber two switching pieces, each with a first contact region, a movable with a switching bridge and electrically conductive bridge switching piece with two second contact areas for producing an electrically conductive connection between the first and second contact areas and for separating at least one of the second contact areas of the respective first contact area, and at least two magnets for generating a magnetic field.

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 of time 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 given only in a certain current flow direction. 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.

document DE 1 640 804 A1 explains an electrical switching device. In the contact system with bridge contact fixed contacts are formed with extending to both sides rails. Plate-shaped permanent magnets are mounted parallel to the rails on the outer walls of an arc chamber, which generate a magnetic field perpendicular to the rails, which blows out the arc between the bridge and fixed contact forming up or down depending on the current direction. To increase the Blasfeldes further plate-shaped permanent Blasmagnete can be mounted in the space given by the bridge between the two parallel rail and chamber arrangements.

document GB 2 058 463 A deals with an electrical switch with means for extinguishing an arc. The switch comprises two contact pieces, each with a stationary contact. Further, the switch comprises a bridge contact with two contact elevations and two magnets, which are arranged next to the two switching pieces. At the bridge contact another magnet is arranged.

An object of the invention is to provide a switch with a faster and / or more reliable erasure behavior of resulting turn-off arcs than the prior art.

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 should in particular be suitable for a DC operation, have one or more switching chambers and preferably be designed to be double-interrupting and / or polarity-independent. According to the invention, each switching chamber has two contact pieces, each with a first contact region, and an electrically conductive bridge contact piece which can be moved with a switching bridge. An electrically conductive connection between the first and second contact regions can be produced via the bridge contact element, wherein a breaker switch can only be disconnected via one of the contact pairs of the first and second contact regions, while the other contact pair remains permanently connected, for example via a stranded conductor. In a double-break switch, a separation of both second contact areas of the respective first contact area. To generate a magnetic field, each chamber has at least two magnets, in particular permanent magnets.

According to the invention it is provided that an additional magnet is arranged on the movable switching bridge. An advantage of this additional magnet is that the magnetic field in the region of the first and second contact regions is particularly well influenced, since the additional magnet passes through the movement of the switching bridge in the immediate vicinity of the first and second contact areas. In particular, the field strength of the magnetic field is significantly increased in this area by the additional magnet, which allows an advantageously accelerated erasing of arcs. The additional magnet is preferably arranged in a recess in the movable switching bridge in height of the contact areas.

The magnetic field is used to exert a magnetic force on the arc or arcs, so that at least one of the arcs, preferably independently of the current direction in the arc, is driven in the direction of one of the extinguishing devices, wherein the contact pieces of the switching chambers are arranged so that the second contact areas are located in a line substantially perpendicular to the direction of movement of the arcs.

The additional magnet is movable to amplify the magnetic field strength with the switching bridge in a region of the separable first and second contact areas. By this is meant that the auxiliary magnet is movable in close proximity to the region of the first and second contact regions, not between the first and second contact regions. The at least two magnets are, for example, at least twice as far away from the first and second contact regions as the additional magnet. The at least two magnets can in particular be arranged outside the switching chamber or in the region of the switching chamber wall, also on the inside of the switching chamber wall, preferably in an insulating pocket. The magnets are preferably designed as at least two plate-shaped magnets whose surfaces are arranged parallel to each other.

According to a preferred embodiment, it is provided that at least two extinguishing devices are provided per switching chamber or contact pair for extinguishing arcing, which can occur during separation of the first and second contact regions. Particularly preferably four erasing devices are provided for polarity-independent erasing of the arcs.

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, wherein a distance of the first arc conductors from the second arc conductors particularly preferably increases in the direction of the extinguishing devices , Further preferably, the bridge switching piece extends in a direction approximately perpendicular to an extension direction of the switching pieces.

According to a further preferred embodiment, it is provided that at least two switching chambers are provided for a multi-pole operation. In this case, the two switching chambers in particular have a common switching bridge for moving the bridge contact pieces and for electrical insulation of the switching chambers against each other. Particularly preferably, an additional magnet is arranged on the common switching bridge for each switching chamber. Further preferably, it is provided that the two switching chambers are arranged one above the other, seen in a direction of movement of the switching bridge.

According to a further preferred embodiment it is provided that the switch has a modular construction, wherein the switch is provided with only one switching chamber for a single-pole operation and can be extended by adding at least one second switching chamber for a multi-pole operation.

Further preferred switching pieces are designed for multi-pole operation such that the terminals of the switch with respect to their position and / or installation position correspond to a multi-pole AC switch. A faulty wiring due to an unusual position of the connections at DC switches with respect to the AC switches used much more often for a long time is thereby advantageously avoided.

Another object of the invention relates to a switch, which is provided in particular for a DC operation, comprising at least one switching chamber, each switching chamber two switching pieces, each with a first contact region, a movable bridge with a bridge and electrically conductive bridge switching piece with two second contact areas for producing an electrically conductive connection between the first and second contact regions and for separating at least one of the second contact regions of the respective first contact region, and at least two magnets for generating a magnetic field, wherein according to the invention a modular construction is provided, wherein the switch with only one switching chamber for a one-pole operation is provided and can be expanded by adding at least one second switching chamber for a multi-pole operation. The two switching chambers are preferably to be arranged one above the other.

Another object of the invention relates to a switch, which is provided in particular for a DC operation, comprising at least two switching chambers for multi-pole operation, each switching chamber two switching pieces each having a first contact region, a movable bridge with a switching bridge and electrically conductive bridge with two second contact areas for producing an electrically conductive connection between the first and second contact regions and for separating at least one of the second contact regions from the respective first contact region, and at least two magnets for generating a magnetic field, wherein according to the invention the switching pieces are designed for multi-pole operation such that the connections of the switch with respect to their position and / or mounting position correspond to a multi-pole AC switch.

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.

Show it

• FIG. 1 a perspective view of an embodiment of a switch according to the invention;
• FIG. 2 an exploded view of the switch according to FIG. 1 ; and
• FIGS. 3a and 3b two perspective views of a detail of the switch according to FIG. 1 ,

The embodiment according to FIG. 1 shows a switch according to the invention, in particular a multi-pole, independent of the current direction compact switch according to the invention in an operation to show an efficient quenching behavior by the shortest possible arc time. The connections of the main current paths or contact pieces 10a, 20a are arranged opposite to each other at the same level, relative to the installation depth of the switch, as in the case of a commercially available AC contactor. The opposing contact pieces 10b, 20b are in the FIG. 1 arranged behind the switch and therefore only in the rest Figures 2 and 3a or 3b recognizable.

In order to realize a compact circuit arrangement which, when installed in a control cabinet, has a similar installation length and width as a pure AC switch for comparable current intensities, the switch is designed in the form of two overlapping switching chambers 41a, 41b of preferably identical construction.

The switching arrangements for each pole are accommodated in two separate, identical switching chambers 41a, 41b, which are arranged one above the other. Here, the switching chambers 41a, 41b are mounted with their opening sides facing each other. To ensure sufficient electrical insulation, the two switching chambers 41a, 41b are sealed off from each other by a partition 43 made of insulating material. In this way, a cost-effective solution is realized with compact installation conditions. If the partition 43 as a lid is carried out, the switch according to the invention can also be modular, optionally one-pole with only one switching chamber 41b or two-pole with two switching chambers 41a, 41b.

With reference to the exploded view in FIG FIG. 2 the switch according to the invention will be further described. The first pole or the first switching chamber 41a has two contact pieces 10a, 10b, each having a first contact region 11 and a bridge bridge 30 movable and electrically conductive Brückenschaltstück 30 with two second contact areas 31 for producing an electrically conductive connection between the first and second contact areas 11, 31 and for separating the second contact areas 31 from the respective first contact area 11. The second switching chamber 41b has two switching pieces 20a, 20b each having a first contact region 21. The bridge contactor 30 with second contact regions 31 is identical to the first switching chamber 41a and therefore also designated. The movable bridge switching pieces 30 of both poles are in this case arranged one above the other at the common switching bridge 35, whereby a synchronized switching process is realized for both poles.

The first and second contact areas 11, 31 and 21, 31 are also referred to below as fixed contact areas 11, 21 and movable contact areas 31, which form contact pairs. The pairs of contacts each have two opposite, preferably identical extinguishing devices 61, 62. The extinguishing devices are preferably designed as so-called Deion chambers, which consist of a stack arrangement of mutually electrically insulated sheets 66 each having an air gap between two adjacent sheets. Alternatively, the extinguishing devices from a simple niche arrangement without splitter stacks, with walls of insulating material, preferably made of thermosetting plastic or ceramic, exist, the individual niches are spatially sufficiently sealed against each other and each an outer wall with suitably dimensioned exhaust openings is broken, which for pressure relief against the switching operation caused by the switching arcs caused by the pressure increase.

In the direction of the extinguishing devices 61, 62, they are each extended to runner-shaped angled second arc conductors or arc runner plates 32, the outgoing ends in the off case, point approximately in the direction of the outer edges 65 of the extinguishing devices. The movable contact areas 31 are located respectively at the intersection between the bridge contact piece 30, which are rotated by approximately 90 degrees against the connecting axis of two opposing extinguishing devices 61, 62, and the there from right angles outgoing arc runners 32nd

In the FIGS. 3a and 3b FIG. 2 are two perspective views of the switch according to FIG FIG. 1 , but without chamber walls of the switching chambers 41a, 41b, shown. The perspective in FIG. 3a corresponds to the FIG. 1 while the FIG. 3b a 90 degree rotated perspective shows. In contrast to the movable bridge switching pieces 30, the switching pieces 10a, 10b, 20a, 20b are designed differently with the fixed contact areas 11, 21 for the two poles of the switch, which are additionally described below with reference to FIGS FIGS. 3a and 3b to be discribed. In the case of the upper switching chamber 41 a of the one pole, the two contact piece carriers 10 a, 10 b respectively parallel to the longer chamber wall at the lower end of the switching chamber 41 a in this, wherein the one contact piece 10 a immediately behind the inner chamber wall by 90 degrees in a direction parallel to the short side of the switching chamber 41a is angled to be bent again just before reaching the lateral chamber wall by 90 degrees in a direction parallel to a chamber bottom or the partition wall 43. In this way, a parallel offset of the two contact pieces 10a, 10b is achieved, in such a way that both are aligned in parallel to each other current paths in the direction of the longer chamber side. Outside the extinguishing devices 61, 62, they are angled obliquely upward in such a way that the two fixed contacts 11 are arranged at the level of the center of the extinguishing devices 61, 62. As a result, together with the movable bridge contact pieces 30, an arc conductor arrangement results from the second arc conductors 32 and first arc conductors 12, the distance of which increases in the direction of the extinguishing devices 61, 62. Along the arc conductors 12, 32, the arc is expanded by means of a magnetic blow field to a length corresponding to the height of the complete extinguishing device 61 and 62, respectively.

In the lower switching chamber 41b of the second pole, the switching pieces 20a, 20b are designed in a similar manner, but with the difference that both switching pieces 20a, 20b immediately after entry into the switching chamber 41b initially at right angles in a direction parallel to the short side of the switching chamber 41st b are angled so that they run towards the bottom of the chamber. The one switching piece 20a is subsequently angled 90 degrees in the direction parallel to the short chamber wall again to be angled in front of the chamber wall at right angles in the direction parallel to the chamber bottom. In this way, the switching piece 20a is guided parallel to the longitudinal-side chamber wall analogously to the switching chamber 41a of the first pole along the chamber bottom. The second switching piece 20b is again bent at right angles in the region of the chamber bottom in such a way that it is parallel to the first contact piece along the chamber bottom. Analogous to the switching chamber 41a of the first pole, the two switching pieces 20a, 20b extend from the switching chamber wall initially below the extinguishing devices 61, 62. Outside the same, they are angled obliquely upward again, so that the two fixed contact areas 21 at the level of the center of the extinguishing devices 61st , 62 are arranged.

By the described embodiment, a switch is realized with an optimized arc running behavior, in such a way that the resulting switching arcs are directed under the action of magnetic Blasfelder within very short times targeted in the direction of one of the extinguishing device 61, 62. Due to the special design of the contact pieces 10a, 10b, 20a, 20b is further achieved that the connections of the main current paths are arranged with respect to position and depth as in a multi-pole AC switch.

According to the invention in the illustrated embodiment in each of the two Switching chambers 41a, 41b arranged an arrangement of at least two permanent magnets 51a, 51b and an additional magnet 51c. The two magnets 51a, 51b may, for example, be arranged outside the switching chambers 41a, 41b, while the additional magnet 51c for influencing the magnetic field is arranged on the movable switching bridge 35, preferably in each case at the level of the movable contact areas 31. To realize this position, the Bridge switching pieces 30 angled on both sides trapezoidal. As a result, a cost-effective magnet arrangement with a comparatively high magnetic field strength in the region of the switching contacts is realized in this way.

Due to the effective Lorentz force, the permanent magnetic arrangement always causes the partial arcs resulting from the opening of the contacts to be moved in the direction of two of the four extinguishing devices 61, 62 and extinguished there, irrespective of the current direction. The arrangement of the additional magnet 51c directly in the region of the switching contacts allows the generation of a homogeneous magnetic field of high magnetic field strength, which allows due to its blowing rapid propagation of the arc in the direction of the respective extinguishing device 61, 62 and thus a comparatively short residence time of the arc between the contact areas 11, 31 and 21, 31 result, which advantageously reduces the erosion of the contacts and the life of the switch is increased.

The permanent magnets 51a, 51b and 51c are preferably made of ferritic material and / or of rare earth materials such as Nd-Fe-B or Sa-Co and / or of materials which allow the formation of plastic-bonded moldings. The switching chamber housing are preferably made of ceramic or thermosetting plastic and divided into four bays separated by bulkheads, each carrying on one outer exhaust openings.

LIST OF REFERENCE NUMBERS

10a, 10b, 20a, 20b

contact members

11, 21

First, fixed contact areas

12, 22

First, fixed arc conductor

30

Bridging contact member

31

Second, movable contact area

32

Second, movable arc conductor

35

Movable switching bridge

41a, 41b

interrupters

43

partition wall

51a, 51b

magnets

51c

additional magnet

61.62

fighting equipment

65

Outer edge of the extinguishing device

66

sheet

Claims (13)

1. Switch for direct current operation with at least one switching chamber (41a) wherein each switching chamber comprises

   - two contacts (10, 10b) each with a first contact area (11),

   - an electrically conductive bridging contact (30) which can be moved with a switching bridge (35) and has two contact areas (31) for producing an electrically conductive connection between the first and second contact areas (11, 31) and for separating at least one of the second contact areas (31) from the relevant first contact area (11), as well as

   - at least two magnets (51a, 51b) for producing a magnetic field, wherein for each switching chamber at least two extinguishing devices (61) are provided for extinguishing arcs that can occur during separation of the first and second contact areas (11, 31),

   characterised in that
   an additional magnet (51c) for influencing the magnetic field is arranged on the movable switching bridge (35) and the additional magnet (51c) is movable for intensifying the magnetic field strength with the switching bridge (35) in an area of the seperable first and second contact areas (11, 31).
2. Switch according to claim 1 characterised in that the additional magnet (51c) is arranged in a recess in the movable switching bridge (35) at a height of the contact areas (31).
3. Switch according to any one of the preceding claims characterised in that the magnets (51a, 51b) are designed as at least two platelike magnets, the surfaces of which are arranged in parallel to each other.
4. Switch according to any one of the preceding claims characterised in that for one switching chamber four extinguishing devices (61, 62) are provided for the polarity-independent extinguishing of arcs which can occur during the separation of the first and second contact areas (11, 31).
5. Switch according to any one of claims 1 to 4 characterised in that first arc guides (12) extend from the first contact areas (11) and second arc guides (32) extend from the second contact areas (31) in the direction of the extinguishing devices (61, 62).
6. Switch according to claim 5, characterised in that a distance between the first arc guides (12) and the second arc guides (32) increases in the direction of the extinguishing devices (61, 62).
7. Switch according to any one of the preceding claims characterised in that the bridging contact (30) extends in a direction approximately perpendicular to a direction in which the contacts (10a, 10b) extend.
8. Switch according to any one of the preceding claims characterised in that at least two switching chambers (41 a, 41 b) are provided for multi-pole operation.
9. Switch according to any one of the preceding claims characterised in that the two switching chambers (41 a, 41 b) have a joint switching bridge (35) for moving the bridging contacts (30).
10. Switch according to claim 9 characterised in that for each switching chamber (41 a, 41 b) an additional magnet (51 c) is arranged on the joint switching bridge (35).
11. Switch according to any one of claims 8 to 10 characterised in that the two switching chambers (41 a, 41 b) are arranged one above the other.
12. Switch according to any one of the preceding claims characterised by a modular structure, wherein the switch is provided with only one switching chamber (41a) for single-pole operation and can be expanded for multi-pole operation through the addition of at least one second switching chamber (41b).
13. Switch according to any one of the preceding claims, characterised by contacts (10a, 10b, 20a, 20b) for multi-pole operation, wherein the contacts are designed in such a way that in terms of their position and/or their mounting orientation the connections of the switch correspond to a multi-pole AC switch.

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