EP2783378B1 - Switch arrangement for direct current operation with at least one switching chamber - Google Patents

Description

The invention relates to a switching arrangement, which is provided in particular for a DC operation, comprising at least one switching chamber, each switching chamber two switching pieces, each having 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, the extinction of the arc is accelerated by the use of a magnetic field that is poled to exert a driving force on the arc toward a quenching chamber. To generate a strong magnetic field are usually permanent magnets 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.

The extinguishing chambers, which serve to extinguish the arc, are intended to keep the period during which the arc burns as short as possible, since the arc releases a large amount of heat, which is used to burn off the contacts and / or the thermal load Switching chamber leads in the switch and thus reduces the life of the switch. The space requirement for switches with corresponding extinguishing chambers, especially for non-polarity switch is significant. In two- or multi-pole switches correspondingly higher amounts of heat are released by arcs than in single-pole switches, which in turn requires larger switch housing with higher space requirements. 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. An arrangement which allows a single-pole circuit can be formed as a bipolar switch arrangement by a further identically constructed arrangement which is set aside.

An object of the invention is to provide a switching arrangement with a fast and reliable erase behavior of resulting Ausschaltlichtbögen available, the space requirement of the amount of heat released is adjusted, without thereby increasing the variety of parts of the switch housing is increased.

The object is achieved by the switching arrangement according to claim 1. In the dependent claims preferred embodiments and advantageous developments are given. The switching arrangement according to the invention should be suitable in particular for a direct current operation, and has one or more switching chambers and is 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. About the bridge contact piece is an electrically conductive connection between the first and second contact areas produced, wherein a easy interrupting switch is separable only via one of the contact pairs of the first and second contact region, while the other contact pair remains permanently connected, for example via a strand. In the case of a double-interrupting switch, the two second contact areas are separated from 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, a modular construction of the switching arrangement is provided, wherein the switching arrangement 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. As a result, by adding a switching chamber per pole, the space requirement of the switching arrangement of the resulting amount of heat can be adjusted by Ausschaltlichtbögen. The modular construction advantageously allows uniform switching chamber components to be used to produce single or multi-pole switches.

A preferred embodiment relates to a two-pole operation of the switching arrangement, wherein two switching chambers are connected to each other such that their respective opening sides face each other. Also preferably, the switching chambers for a two-pole operation by a plate against each other are electrically isolated, the plate is used in a single-pole operation as a cover of the individual switching chamber housing.
In a two-pole operation, the two switching chambers preferably have a common switching bridge for moving the bridge switching pieces. According to a preferred embodiment, it is provided that an additional magnet for influencing the magnetic field is arranged on the movable switching bridge for each switching chamber. 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 in this area is significantly increased by the additional magnet, which advantageously accelerates quenching of Arc allowed. 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 conductor from the second Arc conductors are particularly preferably increased in the direction of the extinguishing devices. Further preferably, each bridge switching piece extends in a direction transversely, in particular approximately at right angles, to an extension direction of the switching pieces. Transverse to a direction is to be understood in the sense not parallel to the direction.
Further preferably, the switching pieces are designed for multi-pole operation such that the terminals of the switching arrangement with respect to their position and / or installation position correspond to a multi-pole AC switch. A faulty wiring due to an unfamiliar position of the terminals in DC switches over the AC switches used much more often over a long time is thereby advantageously avoided.
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.

• Figur 1 eine perspektivische Ansicht einer Ausführungsform einer erfindungsgemäßen Schaltanordnung;
• Figur 2 eine Explosionsdarstellung der Schaltanordnung gemäß Figur 1; und
• Figuren 3a und 3b zwei perspektivische Ansichten eines Details der Schaltanordnung gemäß Figur 1.

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

The embodiment according to FIG. 1 shows a switching arrangement according to the invention, in particular a multi-pole, independent of the direction of the current compact switch, which should show according to the invention in a switching operation 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 switching arrangement 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 switchgear 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 switch chambers 41a, 41b of preferably identical construction, which makes this possible in particular to realize a single-pole switch with only one switching chamber 41b or this modular, by adding a further switching chamber 41 a, to develop a two-pole switch.

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 wall 43 is designed as a cover, then the switching arrangement 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 circuit arrangement 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, respectively a first contact area 21. The bridge switching piece 30 with second contact portions 31 is identical to the first switching chamber 41 a 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 runners 32, wherein the outgoing ends of the bridge 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 in each case at the intersection between the bridge switching piece 30, which are rotated by approximately 90 degrees against the connecting axis of two opposing extinguishing devices 61, 62, and from there perpendicularly outgoing arc running plates 32nd

In the FIGS. 3a and 3b FIG. 2 are two perspective views of the switching arrangement 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 arises from the second arc conductors 32 and first arc conductors 12, whose spacing 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 then again by 90 degrees in the direction parallel to the short Angled chamber wall to be angled in front of the chamber wall again 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 switching arrangement 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 towards 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, an arrangement of in each case at least two permanent magnets 51a, 51b and an additional magnet 51c is arranged in each of the two switching chambers 41a, 41b in the illustrated embodiment. The two magnets 51 a, 51 b may, for example, be arranged outside the switching chambers 41 a, 41 b, while the additional magnet 51 c for influencing the magnetic field is arranged on the movable switching bridge 35, preferably in each case at the height of the movable contact areas 31 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 causes the partial arcs that arise when the contacts are opened to be independent of the direction of flow always in the direction of two of the four total extinguishing devices 61, 62 are moved and extinguished there. 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 51 a, 51 b and 51 c are preferably made of ferritic material and / or of rare earth material, for example Nd-Fe-B or Sa-Co and / or of materials which permit the formation of plastic-bonded molded parts. 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

41 a, 41 b

interrupters

43

partition wall

51a, 51b

magnets

51c

additional magnet

61.62

fighting equipment

65

Outer edge of the extinguishing device

66

sheet

Claims (14)

1. Switching arrangement, comprising at least one switching chamber (41b), wherein each switching chamber has

   - two contact pieces (20a, 20b), each with a first contact area (21),

   - a bridge contact piece (30), which is moveable with a switch bridge (35) and electrically conductive, with two second contact areas (31), configured to establish an electrically conductive connection between the first and second contact areas (21, 31) and to disconnect at least one of the second contact areas (31) from the respective first contact area (21), and

   - at least two magnets (51a, 51b) configured to generate a magnetic field, wherein the switching arrangement has a modular construction, wherein the switching arrangement includes only one first switching chamber (41b) for single pole service and is scalable by adding at least a second switching chamber (41a) for multi-pole service and wherein the connections for the main circuits or the contact pieces (20a, 20b) are arranged opposite at the same level relative to the installation depth of the switching device,

   characterised in that the switching arrangement is configured for multi-pole service in the shape of two switching chambers (41a, 41b) mounted on top of each other.
2. Switching arrangement according to claim 1, characterised in that two switching chambers (41a, 41b) are connected for two-pole service such that their opening sides face each other.
3. Switching arrangement according to any one of the previous claims, characterised in that for two-pole service, the switching chambers (41a, 41b) are electrically insulated from each other by a panel (43), wherein for single pole service, the panel (43) serves as a cover for the individual switching chamber housing (41a).
4. Switching arrangement according to any one of the previous claims, characterised in that in two-pole service, the two switching chambers (41a, 41b) have a common switch bridge (35) configured to move the bridge contact pieces (30).
5. Switching arrangement according to claim 4, characterised in that an additional magnet (51c) is provided for each switching chamber (41a, 41b) to influence the magnetic field on the moveable switch bridge (35).
6. Switching arrangement according to claim 5, characterised in that the additional magnet (51c), together with the switch bridge (35), is moveable in an area of the first and second disconnectable contact areas (11, 21, 31) in order to strengthen the magnetic field.
7. Switching arrangement according to claim 5 or 6, characterised in that the additional magnet (51c) is arranged in a recess in the moveable switch bridge (35) at the height of the contact areas (31).
8. Switching arrangement according to any one of the previous claims, characterised in that the magnets (51a, 51b) are configured as at least two plate-shaped magnets, the surfaces whereof are arranged parallel to one another.
9. Switching arrangement according to any one of the previous claims, characterised in that at least two pieces of quenching equipment (61) are provided for a switching chamber to quench electrical arcs that can occur when disconnecting the first and second contact areas (11, 21, 31).
10. Switching arrangement according to any one of the previous claims, characterised in that four pieces of quenching equipment (61, 62) are provided for a switching chamber for polarity insensitive quenching of electric arcs that can occur when disconnecting the first and second contact areas (11, 21, 31).
11. Switching arrangement according to claim 9 or 10, characterised in that first electric arc conductors (12) extend from the first contact areas (11, 21) and second electric arc conductors (32) from the second contact areas (31) in a direction of the quenching equipment (61, 62).
12. Switching arrangement according to claim 11, characterised in that a distance between the first electric arc conductors (12) and the second electric arc conductors (32) increases in a direction of the quenching equipment (61, 62).
13. Switching arrangement according to any one of the previous claims, characterised in that each bridge contact piece (30) extends in a direction perpendicular to an extension direction of the contact pieces (10a, 10b, 20a, 20b).
14. Switching arrangement according to any one of the previous claims, characterised by contact pieces (10a, 10b, 20a, 20b) for multi-pole service, wherein the contact pieces are configured such that the connections of the switching arrangement correspond to a multi-pole AC switch with regard to their position and / or mounting position.

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