EP3048626A1 - Switching device with permanent magnetic arc extinction - Google Patents

Abstract

The present invention relates to a switching device having at least one contact point and an arc blowing device associated with the contact point, wherein the arc blowing device has at least one blowing magnet for generating a magnetic blowing field, and wherein the blowing field is such that a resulting when opening the contact point switching arc blown from the contact point becomes. According to the invention, the blower field has a first magnetic field region and a second magnetic field region arranged next to the first magnetic field region, wherein magnetic field lines of the first magnetic field region are oriented opposite to magnetic field lines of the second magnetic field region, and wherein the blow field furthermore has a transition region comprising the first magnetic field region and the first magnetic field region connects the second magnetic field region with each other, wherein the orientation of the magnetic field lines in the transition region, starting from each of the first magnetic field region and the second magnetic field range, converges towards the contact point, so that the switching arc within the transition region depending on the current direction starting from the contact point either in the first magnetic field or passed into the second magnetic field region and blown away in both cases in the same direction from the contact point.

Description

The present invention relates to a switching device according to the preamble of independent claim 1.

A generic switching device has at least one contact point and one of the contact point associated with electric arc blowing device. The arc blowing device comprises at least one blowing magnet for generating a magnetic blowing field. The blower field is such that a switching arc arising when the contact point is opened is blown out of the contact point.

A generic switching device is for example off EP 2230678 A2 known. It is an arc-resistant contactor whose arc blowing device comprises both permanent magnets and electrically operated blow coils. The use of blow coils to generate a magnetic blowing field usually means that the switching device is relatively heavy, large and also expensive to manufacture. In addition, the blowing effect on the arc is dependent on the current, which leads to critical current ranges. Activation of the puff coils at the moment of switching requires additional expenses.

Object of the present invention is to provide a switching device of the generic type, which ensures a reliable deletion of the switching arc regardless of the current direction and thereby has a simple and inexpensive construction.

The object is achieved by the features of independent claim 1. Accordingly, in a generic switching device then an inventive solution to the problem before, when the blower field has a first magnetic field and arranged next to the first magnetic field second magnetic field, wherein magnetic field lines of the first magnetic field opposite Magnetic field lines of the second magnetic field region are aligned, and wherein the blowing field further comprises a transition region connecting the first magnetic field region and the second magnetic field region, wherein the orientation of the magnetic field lines in the transition region, starting from each of the first magnetic field region and the second magnetic field region, towards the contact point equalizes, allowing the switching arc inside of the transition region, depending on the current direction, is conducted either from the contact point into the first magnetic field region or into the second magnetic field region, where it is blown away from the contact point in the same direction in both cases.

The solution according to the invention has the advantage that the switching arc is always blown out of the housing of the switching device in the same direction, regardless of the current direction, so that only an arc-quenching device is required to extinguish the switching arc. The magnetic blowing field can be generated purely permanent magnetic, so that can be completely dispensed with the use of heavy and expensive puffing. The switching device according to the invention is characterized very compact. The switching arc arises in the middle of the transition region of the blower field and is therefore conducted as a function of the current direction either in the first magnetic field region or in the second magnetic field region. The magnetic field lines are fanned out in the transition region preferably over an angle of 180 °. A particularly simple construction results if the second magnetic field region is formed in mirror image to the first magnetic field region.

Advantageous embodiments of the present invention are the subject of the dependent claims.

In a preferred embodiment of the present invention, a first channel is assigned to the first magnetic field region and a second channel to the second magnetic field region, the first channel and the second channel being parallel and arranged next to one another, and the first channel being transverse to its longitudinal extension from the magnetic field lines of the first Magnetic field region, and the second channel is traversed transversely to its longitudinal extent by the magnetic field lines of the second magnetic field region.

By providing the channels, the switching arc can be safely and reliably led away from the contact point.

In a further preferred embodiment of the present invention, the switching device further comprises an arc quenching device, which is arranged such that the switching arc is blown into the arc quenching device independently of the current direction through the arc blowing device. As a result, a reliable deletion of the switching arc is achieved in a cost effective manner.

In a further particularly preferred embodiment of the present invention, the arc blowing device has a first lateral pole plate, a second lateral pole plate and a middle pole plate arranged therebetween, the first magnetic field region between the first lateral pole plate and the middle pole plate, and wherein the second magnetic field region between the second lateral Pole plate and middle pole plate. In this embodiment, the blower field can be generated accurately and easily. Furthermore, this embodiment allows a particularly compact and structurally favorable solution. In the first magnetic field region and in the second magnetic field region, the magnetic field lines are substantially perpendicular to the pole plates. The previously mentioned channels each extend between a lateral pole plate and the middle pole plate. The pole plates preferably form the side walls of the channels.

In a further particularly preferred embodiment of the present invention, the first lateral pole plate is assigned at least one first blowing magnet, and the second lateral pole plate is assigned at least one second blowing magnet, wherein the first blowing magnet and the second blowing magnet are oppositely poled. First blowing magnet and second blowing magnet are preferably each arranged between a lateral pole plate and the middle pole plate. Further preferably, the first blowing magnet is in direct contact with the first side pole plate, the second blowing magnet is preferably in direct contact with the second side pole plate.

In a further likewise particularly preferred embodiment of the present invention, the middle pole plate is shorter than the two lateral pole plates at least at one of the contact point facing first end. As a result, a particularly advantageous fanning of the magnetic field lines in the transition region is achieved. It is particularly advantageous if the two lateral pole plates extend laterally next to the contact point, so that the contact point is between a first end of the first lateral pole plate and a first end of the second lateral pole plate. In this way, it is ensured that the switching arc is reliably conducted after its formation as a function of the current direction either in the first magnetic field region or in the second magnetic field region. Further preferably, the middle pole plate at a second end opposite its first end is also shorter than the two lateral pole plates. This will make the switching arc before entering the Arc quenching led back into the middle, so to speak in the plane of symmetry of the middle pole plate. As a result, the arc quenching device can be made particularly compact.

In a further particularly preferred embodiment of the present invention, the contact point comprises a fixed contact and a movable contact, wherein the fixed contact a first Lichtbogenleitblech and a second arc guide are associated with the first arc guide plate and the second arc guide each between contact point and arc quenching device and conductive with the fixed contact, the movable contact being associated with a third arc guide plate and a fourth arc guide plate, the third arc guide plate and the fourth arc guide plate also extending respectively between the pad and the arc quenching device, and wherein the third arc guide plate and the fourth arc guide plate respectively from the movable contact and wherein the first arc guide plate and the third arc guide plate a, the first magnetic field associated with the first P aar of arc guide plates and the second arc guide plate and the fourth arc guide plate, the second magnetic field associated second pair of Lichtbogenleitblechen form, and wherein the Lichtbogenleitbleche the first and second pair of the contact point starting in each case run apart so that the switching arc either between the first arc guide plate and third Arc guide plate or between the second arc guide plate and fourth arc guide plate is stretched when the switching arc is blown through the arc blower in the arc quenching device. In this embodiment, the deletion of the switching arc is considerably simplified by its extension. The third and the fourth arc guide plate are not connected to the movable contact. They can therefore be easily attached to a stationary component of the switching device. As a result, the mass, which is connected to the movable contact and thus must be accelerated when closing or opening the contact point remains very low. The drive of the movable contact can be dimensioned correspondingly small. So that the switching arc can jump over from the movable contact to the third or fourth arc guide plate, it is advantageous if there is only a slight gap between the third and fourth arc guide plate and the movable contact. The first and the second arc guide plate, however, are preferably firmly connected to the fixed contact and more preferably made in one piece with the fixed contact. In this way, only a few components must be manufactured and installed. The design of the switching device remains simple and inexpensive.

In a further particularly preferred embodiment of the present invention, the switching device has a first contact point and a second contact point, wherein the movable contacts of the first and second contact point are arranged on a common contact bridge, and wherein the third arc guide plate and the fourth arc guide plate at the first contact point are electrically connected to the third arc guide plate and the fourth arc guide plate at the second contact point. In this embodiment, it is ensured in a simple manner that the switching arc jumps over the arc guide plates and guided between the respective affected Lichtbogenleitblechen on the way to the associated arc quenching device and thereby stretched.

It is particularly preferably provided that the third arc guide plate is electrically conductively connected at the first contact point via a first electrically conductive connection with the third or fourth arc guide at the second contact point, wherein the fourth arc guide plate at the first contact point via a second electrically conductive connection with the other third or fourth arc guide plate are electrically conductively connected to the second contact point, wherein between the first electrically conductive connection and the second electrically conductive connection, a third electrically conductive connection, and wherein in the third electrically conductive connection preferably a diode is provided, which allows only one direction of current. In this embodiment, the switching device according to the invention is not only suitable for DC operation but also for AC operation. Even if an alternating voltage is applied to the switching device, there is a reliable deletion of the switching arc. If the switching arc occurs at the first contact point, for example, during a positive half-wave, it is conducted with appropriate polarity in the first magnetic field, the current flows, inter alia, via the switching arc at the first contact point, the diode and the switching arc at the second contact point. After completion of the positive half wave no current can flow, because the diode prevents current flow in the opposite direction. It comes to a reconsolidation, the switching arc breaks down. The third electrically conductive connection may be performed anywhere between the first and second electrically conductive connections. For example, it is possible to provide the third electrically conductive connection between the third and fourth arc guide plate at the first contact point. The design effort is particularly low when the third and fourth arc guide plates are connected in parallel to each other at the first and second contact point. This means that the third arc guide plate at the first contact point is electrically conductively connected to the opposite third arc guide plate at the second contact point, and the fourth arc guide plate at the first contact point is electrically conductively connected to the opposite fourth arc guide plate at the second contact point. The third and fourth arc guide plates can be connected to each other at a correspondingly changed polarity of the magnetic blowing field at one of the two contact points, but also crosswise.

In a further preferred embodiment of the present invention, the switching device has a first contact point and an adjacently arranged second contact point, wherein the middle pole plate at the first contact point and the middle pole plate at the second contact point are magnetically differently poled. This optimizes the blowing fields at the two contact points. The middle pole plate at the first contact point is preferably aligned with the middle pole plate of the second contact point.

In a further particularly preferred embodiment of the present invention, the blowing magnet or magnets are exclusively permanent magnets. As a result, the switching device according to the invention is particularly simple and inexpensive to produce. The compact design can be further optimized if the permanent magnets are rare earth magnets.

According to another particularly preferred embodiment of the present invention, the switching device has a first contact point and a second contact point, wherein the first contact point is associated with a first arc blowing device and the second contact point with a second arc blowing device, wherein the first contact point has a first fixed contact and a first movable contact wherein the second contact point has a second fixed contact and a second movable contact, wherein the first movable contact and the second movable contact are arranged at opposite ends of a common contact bridge, wherein the at least a first arc guide plate and the second fixed contact at least a second arc guide plate is associated with the first fixed contact, wherein the first arc guide plate and the second arc guide between the respective fixed contact and the arc quenching device and are conductively connected to the respective fixed contact, wherein further comprises a third arc guide plate and a fourth arc baffle are provided, wherein the third arc baffle and the fourth arc baffle each extend arcuately from the first movable contact to the second movable contact, so that the third arc baffle and the fourth arc baffle together with the contact bridge in each case forms an almost closed loop, and wherein the middle pole plates the first and second arc blowing devices are each arranged between the third and fourth arc guide plates.

This embodiment is particularly simple and can therefore be produced inexpensively. At the same time results in this embodiment, a particularly high erasing potential, both in DC operation and in AC operation. The first arc blowing device and the second arc blowing device are essentially mirror-symmetrical to one another. Therefore, in this embodiment, the magnetic polarity of the pole plates of the first arc blower coincides with the magnetic polarity of the pole plates of the second arc blower. The ends of the third and fourth arc guide plates are each slightly spaced from the ends of the contact bridge, so that the contact bridge can be moved relative to the third and fourth arc guide plate. A base of the arc jumps from the contact bridge to the third and fourth arc guide plate when the arc is blown out of the contact point. A particularly advantageous construction results when the contact bridge is arranged over the fixed contacts. The first arc guide plate and the second arc guide plate are preferably arranged below the respective middle pole plate and extend in width both via the first channel and via the parallel second channel of the associated arc blowing device. They preferably each connect the fixed contact with the associated connection contact. The corners of the contact bridge are preferably rounded to increase the life.

According to a particularly preferred development, the first blowing magnet of the first arc blowing device and the first blowing magnet of the second arc blowing device disposed within the loop formed by the third arc guide plate and the contact bridge, wherein the second blowing magnet of the first arc blowing device and the second blowing magnet of the second arc blowing device are disposed within the loop, which is formed by the fourth arc guide plate and the contact bridge. As a result, the blowing magnets are easily shielded from the arc. A protective sheath of the blowing magnets made of ceramic or the like is not required.

In a further preferred development, the middle pole plates of the first and second arc blowing devices are encased in an electrically insulating manner. The sheath can be made of suitable plastic or ceramic.

According to a further preferred development of this embodiment, the arc quenching device has a first arc quenching device and a second arc quenching device, wherein first and second arc quenching devices are arranged on opposite sides of a housing of the switching device such that the first channel and the second channel of the first arc blowing device open into the first arc quenching device, wherein the first and second channels of the second arc blower open into the second arc extinguishing device. Particularly preferably, a third arc quenching device is arranged on a top side of the housing connecting the two opposite sides of the housing, such that the first and second channels of the first and second arc blowing devices also open into the third arc quenching device. As a result, the deletion potential can be increased if necessary. Parts of the housing, which lie between the arc quenching device, can be protected if necessary by suitable copper plates from the arc. Further, it is advantageous if the arc quenching device, optionally together with the two arc blowing devices, for maintenance purposes completely removed from the housing of the switching device to allow easy access to the fixed contacts and the contact bridge. The drive of the switching device is advantageously below the two fixed contacts.

According to an advantageous embodiment, the arc-extinguishing devices each have a plurality of extinguishing elements which are stacked on one another. The extinguishing elements can be made of ceramic. The extinguishing elements have at that end, the Contact point or the third and fourth arc guide plate facing, in each case at least two wedge-shaped flanks, wherein the wedge-shaped flanks of each extinguishing element with the wedge-shaped flanks of each successive extinguishing element to two V-shaped grooves, which are each associated with one of the two channels, complete. Depending on the current direction of the arc is blown either through the first channel or through the second channel of the respective arc blower in one of the two V-shaped grooves. The arc quenching devices each have a plurality of openings to the outside, so that the plasma generated by the switching arc can escape from the housing of the switching device. The openings are preferably formed by corresponding grooves in the extinguishing elements.

The switching capacity can be further increased if the contact bridge is arranged according to a further preferred embodiment on a contact carrier made of electrically insulating material, wherein the contact carrier extends between the first contact point and the second contact point on the inside width of the housing of the switching device. Particularly preferably, the contact carrier dips on both sides into corresponding grooves of the housing, so that a barrier in the manner of a labyrinth seal is formed for the plasma which is formed by the arc. Below the contact carrier, a bellows may also be arranged to avoid a short to ground, which otherwise takes place due to the arc generated by the arc in a flashover of the arc on the yoke plate of the drive of the switching device, if correspondingly high loads are switched.

Most preferably, the switching device is a contactor.

The present invention further provides an arc blowing device for a switching device.

Figur 1:

eine Schrägansicht eines erfindungsgemäßen Schaltgeräts bei geöffnetem Gehäuse gemäß einem ersten Ausführungsbeispiel,

Figur 2:

eine geschnittene Draufsicht auf das erfindungsgemäße Schaltgerät aus Figur 1,

Figur 3:

das Schaltgerät aus den Figuren 1 und 2 in der Ansicht aus Figur 1 kurz nach dem Öffnen der Kontaktstellen,

Figur 4:

die Darstellung aus Figur 3 bei umgekehrter Stromrichtung,

Figur 5:

eine Schrägansicht eines erfindungsgemäßen Schaltgeräts gemäß einem zweiten Ausführungsbeispiel,

Figur 6:

einen Schnitt durch den erfindungsgemäßen Schalter aus Figur 5 entlang der in Figur 5 eingezeichneten Schnittlinie VI (geschnittene Seitenansicht),

Figur 7:

einen Schnitt durch den erfindungsgemäßen Schalter aus Figur 5 entlang der in Figur 5 eingezeichneten Schnittlinie VII (Längsschnitt),

Figur 8:

einen Schnitt durch den erfindungsgemäßen Schalter aus Figur 5 entlang der in Figur 5 eingezeichneten Schnittlinie VIII (geschnittene Draufsicht),

Figur 9:

ein Löschelement der Lichtbogenlöscheinrichtungen des erfindungsgemäßen Schalters aus den Figuren 5 bis 8,

Figur 10:

ein weiteres Löschelement der Lichtbogenlöscheinrichtungen des erfindungsgemäßen Schalters aus den Figuren 5 bis 8,

Figur 11:

die beiden Löschelemente aus den Figuren 9 und 10 im aufeinandergestapelten Zustand.

Embodiments of the present invention are explained in more detail below with reference to drawings. Show it:

FIG. 1:

an oblique view of a switching device according to the invention with the housing open according to a first embodiment,

FIG. 2:

a sectional plan view of the switching device according to the invention from FIG. 1 .

FIG. 3:

the switching device from the FIGS. 1 and 2 in the view FIG. 1 shortly after opening the contact points,

FIG. 4:

the presentation FIG. 3 in reverse current direction,

FIG. 5:

an oblique view of a switching device according to the invention according to a second embodiment,

FIG. 6:

a section through the switch according to the invention FIG. 5 along the in FIG. 5 drawn section line VI (sectional side view),

FIG. 7:

a section through the switch according to the invention FIG. 5 along the in FIG. 5 drawn section line VII (longitudinal section),

FIG. 8:

a section through the switch according to the invention FIG. 5 along the in FIG. 5 drawn section line VIII (cut plan view),

FIG. 9:

an extinguishing element of the arc extinguishing devices of the switch according to the invention from the FIGS. 5 to 8 .

FIG. 10:

another extinguishing element of the arc extinguishing devices of the switch according to the invention from the FIGS. 5 to 8 .

FIG. 11:

the two extinguishing elements from the FIGS. 9 and 10 in the stacked state.

For the following statements applies that the same parts are designated by the same reference numerals. If reference signs are contained in a drawing, which are not discussed in detail in the associated description of the figures, reference is made to preceding or subsequent description of the figures.

FIG. 1 shows an oblique view of a switching device according to the invention 1. The switching device is a single-pole contactor. For the sake of clarity, the housing of the switching device and various other components that are partly in FIG. 2 are shown, not shown. FIG. 2 shows a sectional plan view. The cut passes through the axes of the in FIG. 1 shown components 2.1 and 2.2.

The contactor 1 has two fixed contacts 7.1 and 7.2, which are each electrically connected to an associated terminal contact 8.1, 8.2. The two fixed contacts 7.1 and 7.2 can be electrically connected to each other by means of a contact bridge 10. The contact bridge 10 is actuated by the armature of an electromagnetic drive 19 and has two movable contacts 9.1, 9.2. When closing the contacts comes the first movable contact 9.1 with the first fixed contact 7.1 to the plant. The second movable contact 9.2 contacts the second fixed contact 7.2. As already mentioned, the housing of the contactor 1 is not shown. In the illustration, only the chassis 20 of the switching device is shown, to which the electromagnetic drive is attached.

When opening the contacts is formed between the first fixed contact 7.1 and the first movable contact 9.1 and between the second fixed contact 7.2 and the second movable contact 9.2 each a switching arc.

In order to prevent the switching device from being damaged due to the formation of switching arcs, these must be led out of the contact area and extinguished. In the following, the pairing of the first fixed contact 7.1 and the first movable contact 9.1 is referred to as the first contact point. The pairing of second contact 7.2 and second movable contact 9.2 is referred to as the second contact point. The switching device has an arc blowing device for each of the two contact points in order to blow off the switching arc from the contact point. Each of the two arc blowing devices is associated with an arc quenching device 5.1 or 5.2. The arc quenching devices are in FIG. 2 shown schematically and may have a plurality of quenching plates or ceramic extinguishing elements in well-known manner.

The structure of the arc blowing device is first explained for the first contact point, consisting of the first fixed contact 7.1 and the first movable contact 9.1. The blowing field that is generated by the arc blowing device is generated exclusively permanent magnetic in the switching device according to the invention. No electrically operated blower coils are required. Thus, only the two permanent magnets 2.1 and 2.2 are used. The two permanent magnets 2.1 and 2.2 are each arranged between the first contact point and the arc quenching device 5.1, which is assigned to the first contact points. The first permanent magnet 2.1 stands in direct contact with a first lateral pole plate 6.1, which is arranged on a side wall of the switch housing, not shown. The second permanent magnet 2.2 is also in direct contact with a second lateral pole plate 6.2, which is arranged on the opposite side of the housing and in FIG. 1 for reasons of better clarity is not shown. Between the two lateral pole plates 6.1 and 6.2 is a middle pole plate 6.3, which runs parallel to the two lateral pole plates 6.1, 6.2 and in FIG. 1 also not shown. Between the two permanent magnets and the middle pole plate 6.3 a magnetic yoke is arranged in each case. Both the conclusion and the permanent magnets are cylindrical. In FIG. 2 It can be seen that both components are each surrounded by a protective sleeve 21.

The two permanent magnets 2.1 and 2.2 are oppositely poled. The south pole is located in each case on the outside of the first pole plate 6.1 or on the second pole plate 6.2. The common north pole is located at the middle pole plate 6.3. The opposite polarity causes the magnetic field established between the second lateral pole plate 6.2 (right) and the middle pole plate 6.3 to be aligned exactly opposite the magnetic field established between the first pole plate 6.1 (left) and the middle pole plate 6.3 becomes. This circumstance can also be seen from the magnetic field lines 23, which are shown in FIG FIG. 2 are drawn.

The pole plates define between them two channels, both of which open respectively starting from the first contact point in the arc quenching device 5.1. In this case, there is a first channel 4.1 between the first lateral pole plate 6.1 and the middle pole plate 6.3. Between the second lateral pole plate 6.2 and the middle pole plate 6.3 is a second channel 4.2. The two channels are interspersed transversely to their longitudinal extent of one of the two oppositely poled magnetic fields. How out Figure 2 becomes clear, extend the two lateral pole plates 6.1, 6.2 laterally next to the contact point, the middle pole plate 6.3 is slightly shorter and ends before the contact point. This results in a transition region of the magnetic blowing field at the contact point. Approximately in the middle of the fixed contact 7.1 or the movable contact 9.1, the magnetic field lines are perpendicular to the magnetic field lines of the two magnetic fields in the channels 4.1 and 4.2. In the transition region, the magnetic field lines are fanned out virtually over an angle of 180 °. The direction of the magnetic field in the channel becomes 4.1 This reversed in the transition region until it finally corresponds to the direction of the magnetic field in the channel 4.2.

If the first connection contact 8.1 is now connected to the positive pole of a voltage source, then a switching arc 3.1 is produced when the contacts are opened at the first contact point, which is triggered by the magnetic blow field in FIG FIG. 2 first deflected to the right and then enters the channel 4.2 between the second lateral pole plate 6.2 and the middle pole plate 6.3. The direction of movement of the switching arc 3.1 is illustrated for this case by the arrow 24. If the first connection contact 8.1 is connected to the negative pole of the voltage source, then the switching arc is initially deflected in the opposite direction to the left. It then enters the left channel 4.1 between the first lateral pole plate 6.1 and the middle pole plate 6.3 along the path illustrated by the arrow 25. In both cases, the switching arc is subsequently driven through the magnetic blow field into the arc quenching device 5.1. The middle pole plate 6.3 is also at the opposite end, which faces the arc quenching device 5.1, slightly shorter than the two lateral pole plates 6.1, 6.2. As a result, the magnetic blower field also has a transition region, shortly before the arc-quenching device 5.1, which conducts the switching arc to the middle of the arc-quenching device 5.1. As a result, the arc quenching device 5.1 can be kept compact.

At the second contact point, which is formed by the second fixed contact 7.2 and the second movable contact 9.2, an arc blowing device is also provided, which is constructed substantially identical to the arc blowing device at the first contact point. The only significant difference is that the two permanent magnets 2.1, 2.2 are reversed. At the second contact point, the middle pole plate 6.3 marks the south pole. The two lateral pole plates 6.1 and 6.2 each form the north pole of the magnetic field. If the first terminal contact 8.1 with the positive pole, and the second terminal contact 8.2 connected to the negative pole of a voltage source, resulting at the second contact point switching arc 3.2 is thus initially deflected to the left and then enters the channel between the left side pole plate 6.1 and middle pole plate 6.3. When the voltage is reversed, the switching arc 3.2 at the second contact point to the right deflected and therefore enters the channel between the right side pole plate 6.2 and the middle pole plate 6.3.

In FIG. 1 It can be seen that a plurality of so-called arc guide are provided to guide the switching arc on the one hand and to stretch on the way to the arc quenching on the other. The arrangement of the arc guide plates is first explained again below for the first contact point. The first fixed contact 7.1 has a first arc guide plate 11.1 and a second arc guide plate 12.1. The opposite first movable contact 9.1 are also associated with two Lichtbogenleitbleche, namely a third arc guide plate 13.1 and a fourth arc guide plate 14.1. The third arc guide plate 13.1 and the fourth arc guide plate 14.1 are not connected to the movable contact 9.1 or to the contact bridge 10, but permanently installed in the switching device. Between the third arc guide plate 13.1 and the contact bridge 10 and between the fourth arc guide plate 14.1 and the contact bridge 10 there is therefore in FIG. 2 indicated gap 22. The first arc guide plate 11.1, together with the third arc guide plate 13.1 an arc guide plate pair, which is assigned to the first channel 4.1 between the first side pole plate 6.1 and the middle pole plate 6.3. The second arc guide plate 12.1, together with the fourth arc guide plate 14.1, likewise forms an arc guide plate pair, which is assigned to the second channel 4.2 between the second lateral pole plate 6.2 and the middle pole plate 6.3. The two arc guide plates of an arc guide plate pair run apart from the contact point in order to stretch the switching arc on the way to the arc quenching device.

Corresponding arc guide plates are likewise provided at the second contact point, the third and fourth arc guide plates 13.1, 14.1 being in each case electrically connected at the first contact point to the corresponding third and fourth arc guide plates 13.2, 14.2 at the second contact point. This means that the third arc guide plate 13.1 at the first contact point is conductively connected via an electrical connection 15 to the third arc guide plate 13.2 at the second contact point. Likewise, the fourth arc guide plate 14.1 is electrically connected at the first contact point via an electrical connection 16 to the fourth arc guide plate 14.2 at the second contact point. In addition, there is an electrical connection between the third arc guide plate 13.1 and the fourth arc guide plate 14.1 at the first contact point Connection 17, in which a diode 18 is provided, which allows only one direction of current. It should be noted that the diode is only required if the contactor is used in AC applications. The second fixed contact 7.2 is connected to the two arc guide plates 11.2 and 12.2. The arc guide plate 11.2 forms the first arc guide plate at the second contact point. The arc guide plate 12.2 forms the second arc guide plate.

The function of the arc guide plates and the corresponding electrical connection lines is explained in more detail below. If the first connection contact 8.1 with the positive pole and the second connection contact 8.2 are connected to the negative pole of a voltage source, the switching arc 3.1, which arises at the first contact point, enters the second channel 4.2 between the second lateral pole plate 6.2 and the middle pole plate 6.3 one. At the time of the emergence of the switching arc 3.1, this exists between the first fixed contact 7.1 and the first movable contact 9.1, which is arranged on the contact bridge 10. In order to be able to enter the channel 4.2, the switching arc must jump from the contact bridge 10 to the fourth arc guide plate 14.1. The current flows from the first fixed contact 7.1 via the second arc guide plate 12.1, the first switching arc 3.1, the fourth arc guide plate 14.1, the electrical connection line 17, the third arc guide plate 13.1, the electrical connection line 15, the third arc guide plate 13.2 at the second contact point, the second Switching arc 3.2 and the first arc guide plate 11.2 at the second contact point to the second fixed contact 7.2. This case is in FIG. 3 shown.

With oppositely applied voltage, the in FIG. 4 shown case. The current flows from the second fixed contact 7.2 via the second arc guide plate 12.2 at the second contact point, the second switching arc 3.2, the fourth arc guide 14.2, the electrical connection line 16, the fourth arc guide plate 14.1, the electrical connection line 17, the third arc guide plate 13.1, the first Switching arc 3.1 and the first Lichtbogenleiblech 11.1 at the first contact point to the first fixed contact 7.1. In both cases, the first switching arc 3.1 and the second switching arc 3.2 are appropriately stretched by the arc guide plates and finally extinguished in the associated arc quenching device.

By using the diode 18 in the electrical connection line 17 between the third arc guide plate 13.1 and the fourth arc guide plate 14.1 at the first contact point, the switching device according to the invention is also suitable for AC operation. If the switching arcs 3.1 and 3.2 occur during the positive half cycle, then the in FIG. 3 shown state. At a mains frequency of 50 Hz, the duration of the positive half cycle is 10 milliseconds. This leaves enough time so that the switching arc can jump from the contact bridge to the corresponding arc guide plate. The transition to the negative half wave is simply prevented by the use of the diode 18. The current direction can not reverse. It comes to a reconsolidation, whereby the switching arc in the negative half-wave can not re-ignite. The same applies in the event that the switching arc occurs during the negative half-wave. In this case, first the in FIG. 4 shown situation. Again, it comes to a reconsolidation and to prevent re-ignition of the arc.

The FIGS. 5 to 8 show a second embodiment of a switching device according to the invention 1. The structure corresponds in principle to the structure of the switching device from the FIGS. 1 to 4 , Like parts are designated by like reference numerals. In the following, essentially the differences from the first embodiment will be apparent from FIGS FIGS. 1 to 4 described.

How out FIG. 6 shows, the contact bridge 10 is arranged with the two movable contacts 9.1 and 9.2 in contrast to the first embodiment above the two fixed contacts 7.1 and 7.2. The electromagnetic drive 19 is located as in the first embodiment below the two contact points. This has the advantage that the upper part of the housing can be completely removed for maintenance purposes, allowing free access to the contacts. The locking of the upper housing part by means of in FIG. 5 shown bolt 26.

Also, the switching device according to the second embodiment has two contact points. The first contact point 7.1 / 9.1 is associated with a first arc blowing device, the second contact point 7.2 / 9.2 is associated with a second arc blowing device. The first arc blower is in FIG. 8 shown in the lower half, the second arc blower takes in FIG. 8 the upper half of the picture. The first arc blowing device and the second arc blowing device are substantially built mirror-symmetrically to each other. The magnetic polarity of the pole plates 6.1, 6.2 and 6.3 of the first arc blowing device in this embodiment is therefore identical to the magnetic polarity of the pole plates 6.1, 6.2 and 6.3 of the second arc blowing device.

The arc quenching device of the switching device 1 has on opposite sides of the housing a first arc quenching device 5.1 and a second arc quenching device 5.2. The first arc quenching device 5.1 is assigned to the first contact point 7.1 / 9.1. First channel 4.1 and second channel 4.2 of the first arc blowing device, which is assigned to the first contact point, respectively open into the first arc-extinguishing device 5.1. The second arc quenching device 5.2 is assigned to the second contact point 7.2 / 9.2. First channel 4.1 and second channel 4.2 of the second arc blowing device, which is assigned to the second contact point, respectively open into the second arc-extinguishing device 5.2. On the upper side of the housing, a third arc-quenching device 5.3 is further arranged, wherein the first and second channels of the first and second arc-blowing devices also open into the third arc-quenching device 5.3. The third arc quenching device increases the quenching potential as needed. Parts of the housing that lie between the arc extinguishing devices can be protected from the arc by suitable copper plates 32. All three arc extinguishing devices 5.1, 5.2, and 5.3 each have a plurality of extinguishing elements 29 and 30, which are stacked alternately. The extinguishing elements are made of ceramic. They have at the end which faces the contact point, in each case two wedge-shaped flanks, wherein the wedge-shaped flanks of a first in FIG. 9 shown extinguishing element 29 with the wedge-shaped flanks of a subsequent second extinguishing element 30 to two V-shaped grooves 31, which are each associated with one of the two channels 4.1 and 4.2 complete. The second erasing element 30 is in FIG. 10 shown, the resulting V-shaped grooves are in FIG. 11 shown. Depending on the current direction of the arc is blown either through the first channel 4.1 or through the second channel 4.2 of the respective arc blowing device in one of the two V-shaped grooves.

The first fixed contact 7.1 is assigned a first arc guide plate 11 and the second fixed contact 7.2 is associated with a second arc guide plate 12. The first arc guide plate 11 and the second arc guide plate 12 extend between the respective fixed contact 7.1 or 7.2 and the respective associated arc quenching 5.1 or 5.2. They each connect the fixed contact 7.1 or 7.2 with the associated connection contact 8.1 or 8.2. The first arc guide plate 11 and the second arc guide plate 12 are arranged below the respective middle pole plate 6.3 and they extend in width both via the first channel 4.1 and via the parallel second channel 4.2 of the associated arc blowing device. Furthermore, a third arc guide plate 13 and a fourth arc guide plate 14 are provided. The third arc guide plate 13 and the fourth arc guide plate 14 each extend arcuately from the first movable contact 9.1 to the second movable contact 9.2, so that the third arc guide plate 13 and the fourth arc guide plate 14 together with the contact bridge 10 each form a nearly closed loop. As FIG. 6 shows, the middle pole plates 6.3 of the first and second arc blowing device respectively between the third arc guide plate 13 and fourth arc guide plate 14 are arranged. The third arc guide plate 13 is located in the representation of FIG. 6 behind the two middle pole plates 6.3 and is therefore shown in dashed lines in this figure.

The ends of the third arc guide plate 13 and the fourth arc guide plate 14 are each slightly spaced from the ends of the contact bridge 10, so that the contact bridge 10 can be moved relative to the third and fourth arc guide plate. A base of the switching arc jumps from the contact bridge on the third and fourth arc guide plate when the switching arc is blown out of the contact point. The corners of the contact bridge are preferably rounded to increase the life.

The first blowing magnet 2.1 of the first arc blowing device and the first blowing magnet 2.1 of the second arc blowing device are disposed within the loop formed by the third arc guide plate 13 and the contact bridge 10, the second blowing magnet 2.2 of the first arc blowing device and the second blowing magnet 2.2 of the second arc blowing device are arranged within the loop, which is formed by the fourth arc guide plate 14 and the contact bridge 10. As a result, the blowing magnets are easily shielded from the arc. A protective sheath of the blowing magnets made of ceramic or the like is not required.

The middle pole plates 6.3 of the first and second arc blowers are encased in an electrically insulating manner. The contact bridge 10 is arranged on a contact carrier 27 made of electrically insulating material. As FIG. 7 shows, the contact carrier 27 extends between the first contact point and the second contact point on the clear width of the housing of the switching device. The contact carrier dips on both sides into corresponding grooves of the housing, so that a barrier of the type of a labyrinth seal is formed for the plasma formed by the arc. Below the contact carrier 27, a bellows 28 is further arranged to avoid a short to ground, which otherwise takes place due to the arc generated by the arc in a flashover of the arc on the yoke plate of the drive of the switching device, if correspondingly high loads are switched.

In the second embodiment according to the FIGS. 5 to 8 the two switching arcs are 3.1 and 3.2, which arise at the contact points 7.1 / 9.1 and 7.2 / 9.2, in the representation of FIG. 8 depending on the current direction, either first deflected either to the right or both to the left, then into the respective arc quenching device 5.1 or 5.2, and subsequently into the third arc quenching device 5.3. Depending on the current direction, the switching arcs 3.1 and 3.2 are thus either through the channels 4.1 or, as it is in FIG. 6 shown is driven through the channels 4.2 in the arc extinguishing equipment.

Claims (15)

Switching device (1) having at least one contact point and an arcing device associated with the contact point, wherein the arc blowing device has at least one Blasmagneten (2.1, 2.2) for generating a magnetic Blasfelds, wherein the Blasfeld is such that a resulting when opening the contact point switching arc (3.1 3.2) is blown out of the contact point, characterized in that the blowing field has a first magnetic field region and a second magnetic field region arranged next to the first magnetic field region, wherein magnetic field lines of the first magnetic field region are oriented opposite to magnetic field lines of the second magnetic field region, and wherein the blow field further comprises a transition region having the first magnetic field region and the second magnetic field region interconnected, wherein the alignment of the magnetic field lines in the transition region, starting from each of the first magnetic field region and the second In the magnetic field region, the switching arc (3.1, 3.2) within the transition region, depending on the current direction, is conducted from the contact point either into the first magnetic field region or into the second magnetic field region and in both cases in the same direction from the contact point is blown away. Switching device (1) according to claim 1, characterized in that the first magnetic field region, a first channel (4.1), and the second magnetic field region, a second channel (4.2) is assigned, wherein the first channel (4.1) and second channel (4.2) are parallel and are arranged side by side, and wherein the first channel (4.1) is traversed transversely to its longitudinal extent by the magnetic field lines of the first magnetic field region, and the second channel (4.2) transversely to its longitudinal extent of the magnetic field lines of the second magnetic field region. Switching device (1) according to claim 1 or 2, characterized in that the switching device (1) further comprises an arc quenching device (5.1, 5.2, 5.3), which is arranged such that the switching arc (3.1, 3.2) regardless of the current direction through the Arc blowing device in the arc quenching device (5.1, 5.2, 5.3) is blown. Switching device (1) according to one of claims 1 to 3, characterized in that the arc blowing device has a first lateral pole plate (6.1), a second lateral pole plate (6.2) and an intermediate pole plate arranged therebetween (6.3), wherein the first magnetic field region between the first lateral pole plate (6.1) and middle pole plate (6.3), and wherein the second magnetic field region between the second lateral pole plate (6.2) and middle pole plate (6.3) consists. Switching device (1) according to claim 4, characterized in that the first lateral pole plate (6.1) at least a first blowing magnet (2.1), and the second lateral pole plate (6.2) at least a second blowing magnet (2.2) is assigned, said first blowing magnet (2.1 ) and second blowing magnet (2.2) are oppositely poled, and wherein the Blasmagneten (2.1, 2.2) are permanent magnets. Switching device (1) according to claim 4 or 5, characterized in that the middle pole plate (6.3) at least at one of the contact point facing first end is shorter than the two lateral pole plates (6.1, 6.2). Switching device (1) according to claim 6, characterized in that the two lateral pole plates (6.1, 6.2) laterally adjacent to the contact point, so that the contact point between a first end of the first lateral pole plate (6.1) and a first end of the second lateral Pole plate (6.2) is located. Switching device (1) according to claim 6 or 7, characterized in that the middle pole plate (6.3) at a second end opposite to its first end is also shorter than the two lateral pole plates (6.1, 6.2). Switching device (1) according to claim 1 in combination with claims 3 to 5, characterized in that the switching device (1) has a first contact point and a second contact point, wherein the first contact point associated with a first arc blowing device, and the second contact point a second arc blowing device wherein the first contact point has a first fixed contact (7.1) and a first movable contact (9.1), wherein the second contact point has a second fixed contact (7.2) and a second movable contact (9.2), wherein the first movable contact (9.1) and the second movable contact (9.2) at opposite ends of a common contact bridge (10) are arranged, wherein the first fixed contact (7.1) at least a first arc guide plate (11) and the second fixed contact (7.2) at least a second arc guide plate (12) is assigned, wherein the first arc guide plate (11) and the second arc guide plate (12) between the respective fixed contact (7.1, 7.2) and the arc quenching device (5.1, 5.2) extend and conductively connected to the respective fixed contact (7.1 , 7.2), wherein a third arc guide plate (13) and a fourth arc guide plate (14) are further provided, wherein the third arc guide plate (13) and the fourth arc guide plate (14) each arcuately from the first movable contact (9.1) to the second movable contact (9.2) extend so that the third arc guide plate (13) and the fourth arc guide plate (14) together with the contact bridge (10) each forms a nearly closed loop, and wherein the middle pole plates (6.3) of the first and second arc blower between each third and fourth arc guide plate (13, 14) are arranged. Switching device (1) according to claim 9, characterized in that the first blowing magnet (2.1) of the first arc blowing device and the first blowing magnet (2.1) of the second arc blowing device are arranged within the loop, which by the third arc guide plate (13) and the contact bridge (10 ), wherein the second blowing magnet (2.2) of the first arc blowing device and the second blowing magnet (2.2) of the second arc blowing device are disposed within the loop formed by the fourth arc guide plate (14) and the contact bridge (10). Switching device (1) according to claim 9 or 10, characterized in that the central pole plates (6.3) of the first and second arc blowing device are sheathed in an electrically insulating manner. Switching device (1) according to one of claims 9 to 11, in each case in combination with claim 2, characterized in that the arc quenching device (5.1, 5.2, 5.3) comprises a first arc quenching device (5.1) and a second arc quenching device (5.2), wherein first and second arc quenching device (5.1, 5.2) are arranged on opposite sides of a housing of the switching device (1) such that the first channel (4.1) and second channel (4.2) of the first arc blowing device open into the first arc quenching device (5.1), wherein the first channel (4.1 ) and second channel (4.2) of the second arc blowing device in the second arc quenching device (5.2) open. Switching device (1) according to claim 12, characterized in that on a the two opposite sides of the housing connecting top of the housing further comprises a third arc quenching device (5.3) is arranged such that the first and second channels (4.1, 4.2) of the first and second Arc blowing devices in the third arc quenching device (5.3) open. Switching device (1) according to claim 12 or 13, characterized in that the arc quenching device (5.1, 5.2, 5.3), optionally together with the two arc blowing devices, is completely removable. Switching device (1) according to one of claims 9 to 14, characterized in that the contact bridge (10) is arranged on a contact carrier (27) made of electrically insulating material, wherein the contact carrier (27) between the first contact point and the second contact point via the clear width of the housing of the switching device (1) extends.

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