EP2696360A1 - Power switch with extinguishing section for extinguishing an electric arc - Google Patents

Abstract

The switch has a contact body (2) whose switching chamber (4) comprises an extinguishing section (12), where an arc (3) is deflectable in the extinguishing section and formed between contact portions (7) of a contact bridge (1) and a contact piece. The extinguishing section is limited in a longitudinal direction (13) by first and second extinguishing section walls (16, 17) and in a width direction (14) by third and fourth extinguishing section walls (20, 21). The four extinguishing section walls form three closed corners (22) and an open corner (23).

Description

FIELD OF THE INVENTION

The present invention relates to a current switch, preferably a DC current switch, comprising a contact body having at least one switching chamber, in which a contact portion of a contact bridge extending along a direction of the contact bridge in the at least one switching chamber longitudinal direction and extending transversely to the longitudinal direction width direction, and a contact portion of a contact piece are arranged, wherein when opening a switching path, which runs parallel to a height direction pointing from the contact bridge to the contact piece, an arc is formed between the contact portions of the contact bridge and the contact piece under load.

STATE OF THE ART

When opening a current-carrying contact creates, if the conditions are given, an arc. This leads to the burning of the precious metal contacts used. Too long burning times will destroy the contact, even fires are possible. For AC switches of low power classes, the arc extinguishes when next zero crossing of the current by itself. Erasers can therefore be omitted here.

The situation is different for DC, since there are no natural zero crossings, which is why special arc quenching systems are necessary. The latter can take advantage of several simultaneous mechanisms: increasing the arc length; fast switching to reduce the arc time and thus the destruction at the switch; Hard-gas deletion by by the arcing gas (eg, H _2, hydrocarbons) are removed from the insulating material, thereby leading to an increased cooling and rapid quenching of the arc.

It is also known to redirect the arc by means of a magnet, also called Blasmagnet, utilizing the Lorentz force and / or to extend and thus bring more quickly to extinction. In the EP 1998350 A2 For example, an installation switching device is disclosed with a housing comprising two housing halves and an arc extinguishing unit, wherein the arc which arises in an arc precombustion chamber is guided into the arc extinguishing unit by means of a permanent magnet both in alternating current (AC) and direct current (DC) operation. The permanent magnet is arranged in a guide channel and can be inserted into the guide channel in the assembled state of the housing halves through an opening of a housing - later from the outside. In the arc quenching device of EP 1998350 A2 it is a stack arrangement of ferromagnetic arc quenching plates, which are held by a holding device at a distance from each other. In addition, this stack arrangement has a V-shaped recess on an inlet side of the arc, which further increases the manufacturing outlay.

OBJECT OF THE INVENTION

Object of the present invention is to provide a power switch available, which can be used in particular as a DC power switch and has an effective and at the same time as simple as possible and therefore inexpensive extinguishing device. In addition, the structure should allow the use of as many parts as possible existing power switch.

PRESENTATION OF THE INVENTION

To solve the above-mentioned problems, a current switch is provided according to the invention, which comprises a contact body with at least one switching chamber, in which a contact portion of a contact bridge and a contact portion of a contact piece are arranged. Typical embodiments may have a plurality, for example four, of such switching chambers per current switch or contact body. In order to be able to effectively extinguish an arc, which forms when opening a switching path between the contact sections under voltage or load, in the case of direct current (DC), an extinguishing section of the switching chamber is provided, which forms a partial volume of the switching chamber and in which the arc urged / distracted or prolonged. Preferably, the deflection of the arc takes place by means of a permanent magnet, but in principle also other mechanisms can be used, for example an electromagnet or an air pressure system. If a permanent magnet (or electromagnet) is used, then the deflection or extension of the arc takes place by utilizing the Lorentz force.

Core of the invention is a specially designed extinguishing section of the switching chamber, preferably as a recess of the Contact body is executed, is delimited by extinguishing section walls and in which the arc can be steered. The extinguishing section walls thereby form three closed corners and an open corner, wherein the closed corners result from the abutment of deletion section walls and the open corner by the collision of the imaginary extensions of extinguishing section walls. Through the open corner of the arc can be directed into the extinguishing section. As a result, in the erase section, contact is made with at least one erase portion wall of the erase portion, thereby releasing gas and cooling the arc, which in turn results in more rapid extinguishment of the arc. Accordingly, in the case of a current switch, preferably a DC current switch, comprising a contact body having at least one switching chamber, in which a contact section of a contact bridge extending along a longitudinal direction pointing from the contact bridge into the at least one switching chamber and a width direction extending transversely to the longitudinal direction, and a contact portion of a contact piece are arranged, which forms an arc between the contact portions of the contact bridge and the contact piece under load when opening a switching path which is parallel to a pointing from the contact bridge to the contact piece height direction, according to the invention provided that the at least one switching chamber a deleting section in which the arc is deflectable, that the deleting section is bounded longitudinally by a first deleting section wall and a second deleting section wall, that the deleting section in B riding direction is bounded by a third deleting section wall and a fourth deleting section wall, and that the first, second, third and fourth deleting section walls form three closed corners and an open corner. In this case, seen in the longitudinal direction, the first extinguishing section wall in front of the second extinguishing section wall arranged, and seen in the width direction, the third erase portion wall is arranged in front of the fourth erase portion wall.

So that the arc can be directed as freely as possible into the extinguishing section, the open corner is the corner that comes closest to the contact bridge. Accordingly, it is provided in a preferred embodiment of the power switch according to the invention that the open corner of the first and the third extinguishing section wall is formed.

Furthermore, in order to guarantee the unhindered entry of the arc into the quenching section, the quenching section walls are arranged so that the contact bridge is in the open corner as viewed in the longitudinal direction. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the contact bridge is limited in the longitudinal direction of a contact bridge edge and that seen in the longitudinal direction, the contact bridge edge between the first and the second extinguishing section wall is arranged.

In addition, in order to guarantee the unhindered entry of the arc into the quenching section, the quenching section walls are arranged so that the contact bridge is located in the widthwise direction within the open corner. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the contact bridge is limited in the width direction of a contact bridge side edge and that seen in the width direction, the contact bridge side edge between the third and the fourth extinguishing section wall is arranged.

Finally, in order to guarantee the unimpeded entry of the arc into the extinguishing section or the Arc already arise in the extinguishing section, the extinguishing section walls arranged so that the contact bridge is partially arranged in the extinguishing section. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the contact bridge protrudes through the open corner into the extinguishing section.

Since the arc is deflected by a permanent magnet always in the same direction at a given current direction, the deflection of the arc in the erase section can already be guaranteed in this case, when the contact bridge protrudes into the extinguishing section only with a contact bridge corner. It is therefore provided in a particularly preferred embodiment of the power switch according to the invention that the contact bridge projects with a contact bridge corner through the open corner into the extinguishing section, wherein the contact bridge corner is formed by the contact bridge edge and the contact bridge side edge.

Preferably, the deflection of the arc is effected by a permanent magnet, which is arranged in a pocket of the contact body. Opposite existing power switches thus results in a contact body, which has smaller switching chambers due to the necessary accommodation for permanent magnets. Otherwise, only the jumpers are adapted to the reduced switching chambers, so that all other parts can be taken over by the existing power switches.

Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the contact body has at least one pocket for receiving a permanent magnet to deflect the arc into the extinguishing section, wherein the at least one Bag is formed separately from the at least one switching chamber. "Separated" means that there is no connection between the pocket and the interrupter chamber. In particular, it can thus come to no contact between the arc and the permanent magnet, so that damage to the permanent magnet can be avoided by the arc. Only the magnetic field lines of the permanent magnet reach out of the pocket into the switching chamber, so that the arc is deflected into the extinguishing section.

In order to be able to have the permanent magnet act as well as possible on the arc, it is placed as close as possible to the switching path. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the at least one pocket extends parallel to the switching path.

Since the Lorentz force results as a cross product of the velocity vector of the ionized particles in the arc with the magnetic field, it must be ensured for an effective deflection of the arc that the magnetic field lines in any case do not run exactly parallel to the switching path. To achieve this, e.g. a bar magnet can be used, the poles are arranged transversely to the switching path, so that the magnetic field lines are transverse to the switching path. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that in the at least one pocket, a permanent magnet is arranged, wherein the poles are arranged along a direction transverse to the switching path.

If the poles of the permanent magnet are arranged such that the arc is deflected into the extinguishing section for a given current direction, this will generally not be the case with the direction of the current reversed. This because, in the case of a reverse current direction, the Lorentz force points in the opposite direction. That is, the arrangement of the poles of the permanent magnet is not correct for this situation. In order to allow a deflection of the arc in the erase section in the reverse current direction, the arrangement of the poles of the permanent magnet would have to be different. In order to allow a completely correct deflection of the arc into the extinguishing section, the arrangement of the poles of the permanent magnets would have to be exactly the opposite, ie the polarity would have to be reversed.

A solution to this problem can be achieved in bipolar switching. It should be noted that, in accordance with national safety regulations, unipolar ("unipolar") switching may be inadmissible, which makes it particularly attractive to use two-pole current switches. For the two-pole switching in each case a switching chamber pair is provided which consists of two switching chambers according to the invention, preferably with a common contact bridge.

In order to solve the problem of the correct arrangement of the poles or the polarity for both possible current directions, a permanent magnet pair is provided, which consists of two permanent magnets, the poles are arranged differently, preferably gegengleich same or oriented. That the permanent magnets of the permanent magnet pair preferably have an opposite polarity. The permanent magnet pair is arranged in a pocket pair. That the one permanent magnet is arranged in a pocket, which belongs to a switching chamber of the switching chamber pair, the other permanent magnet in another pocket, which belongs to the other switching chamber of the switching chamber pair.

In both switching chambers of the switching chamber pair form arcs when the contact is interrupted. By now the poles the permanent magnets are arranged differently, regardless of the current direction in one of the two switching chambers of the switching chamber pair of arc is pressed or deflected in the extinguishing section, whereas in the other switching chamber of the switching chamber pair, a deflection of the local arc in another, preferably opposite direction. Accordingly, in one of the two switching chambers of the switching chamber pair, an inventive extinguishing of the arc. The thus obtained interruption of the contact in a switching chamber of the switching chamber pair prevents unacceptable loading of the components in the other switching chamber of the switching chamber pair. In the opposite direction of the current correct deflection of the arc - and thus the reliable interruption of the contact - in the other switching chamber of the switching chamber pair takes place. Accordingly, it is provided in a preferred embodiment of the power switch according to the invention that at least one switching chamber pair is provided for two-pole switching, which consists of two switching chambers, preferably with a common contact bridge, that a pair of pockets is provided, which consists of one pocket to each switching chamber of the Switching chamber pair consists, and that a permanent magnet pair is provided, which consists of a respective permanent magnet disposed in each pocket of the pocket pair, and that the poles of the one permanent magnet of the permanent magnet pair are arranged differently than the poles of the other permanent magnet of the permanent magnet pair.

In order to realize a particularly simple form of another arrangement of the poles of a permanent magnet of the permanent magnet pair relative to the arrangement of the poles of the other permanent magnet of the permanent magnet pair, it is provided in a preferred embodiment of the power switch according to the invention that the poles of the one Permanent magnets of the permanent magnet pair are arranged equal to the poles of the other permanent magnet of the permanent magnet pair. This corresponds to an opposite polarity of the two permanent magnets.

For a particularly simple and cost-effective design for the production, it is provided in a preferred embodiment of the power switch according to the invention that the two switching chambers of the switching chamber pair and the two pockets of the pair of pockets seen in the longitudinal direction one behind the other, preferably mirrored about a mirror plane normal to the longitudinal direction are. In this case, the permanent magnets of the permanent magnet pair must be inserted only with opposite polarity in the pockets of the pocket pair, which is from the production point of view, an easy step to be performed.

The switching chamber may have a first switching chamber region, which is designed as a recess of the contact body. In the longitudinal direction, this first switching chamber region is delimited by a first region wall, wherein the first region wall is arranged behind the contact bridge as viewed in the longitudinal direction. Furthermore, the first chamber area is separated from the extinguishing section by means of a web. The web forms an extinguishing section wall into which the arc can be deflected. That is, the web provides a large-area contact between the arc and the wall of the extinguishing section. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the switching chamber has a recess formed as the contact body, first switching chamber region which is bounded in the longitudinal direction by a first region wall, and that between the first switching chamber region and the extinguishing section from a trained contact body Footbridge is arranged.

The switching chamber is designed asymmetrically, the extinguishing section is greater than the first switching chamber area fails to create enough space for the arc or its deflection and extension. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the extinguishing section in the width direction and / or in the longitudinal direction has larger dimensions than the first switching chamber area.

In order to facilitate the arc entry into the extinguishing section, it is provided in a particularly preferred embodiment of the power switch according to the invention that the web has a cross-section which widens in the longitudinal direction V-shaped.

As I said, with a given current direction, the deflection of the arc can be guaranteed by the permanent magnet in the extinguishing section already when the contact bridge projects only with the contact bridge corner in the extinguishing section. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the web is arranged centrally to the extension of the contact bridge in the width direction, preferably centrally to the extension of the contact portion of the contact bridge in the width direction.

Since the web is formed by the contact body, the contact body can be made in one piece. In order to optimize the extinguishing effect by gas release upon contact of the arc with a quenching section wall, the contact body is made of a highly gassing material, preferably made of a polyamide. Thus, in particular hydrogen is released upon contact of the arc with a deletion section wall, which due to its specific heat capacity leads to an efficient cooling and thus to a rapid quenching of the arc. Accordingly, it is at a particularly preferred embodiment of the power switch according to the invention provided that the contact body is made in one piece and made of a polyamide.

In a particularly preferred embodiment of the, preferably equipped with a permanent magnet, power switch is provided as pressure relief of the switching chamber at least one exhaust port. In this case, the at least one blow-out opening connects the interrupter chamber with a terminal space located behind it in the longitudinal direction, into which a terminal connected to the contact piece protrudes. The terminal in turn serves to fix and connect a conductor on or with the contact piece.

Through the exhaust port, a pressure equalization between the switching chamber and terminal space can be done. This also helps to extinguish the arc more quickly by blowing it out. It is therefore provided in a particularly preferred embodiment of the power switch according to the invention that the contact body further comprises at least one terminal space, seen in the longitudinal direction behind the at least one switching chamber, and that at least one exhaust opening is provided, the at least one switching chamber with the at least connects a terminal space.

With regard to the size and positioning of the at least one exhaust opening in the width direction and height direction, there are no fundamental restrictions. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that in the width direction and / or in the height direction, the extension of the at least one exhaust opening is less than or equal to the extension of the at least one switching chamber.

In particular, the first switching chamber area, the land and the bridge offer themselves for positioning the exhaust opening Extinguishing section on. Therefore, it is provided in a particularly preferred embodiment of the power switch according to the invention that the at least one exhaust opening in the first area wall and / or in the second extinguishing section wall, which is arranged in the longitudinal direction behind the first extinguishing section wall, and / or arranged in the web.

A limited expansion of the exhaust opening in the height direction promotes a nozzle effect, which contributes to the blowing out of the arc. This nozzle effect can also be increased by a chamfer facing the exhaust opening. It is therefore provided in a particularly preferred embodiment of the power switch according to the invention, the first area wall and / or the second extinguishing section wall and / or the web has a chamfer pointing towards the at least one exhaust opening.

In a further particularly preferred embodiment variant, the chamfer extends over the entire extent of the at least one exhaust opening in the width direction.

In terms of manufacturing technology, the arrangement of the exhaust opening as the termination of the contact body in the height direction is particularly favorable. Accordingly, in a particularly preferred embodiment of the power switch according to the invention, it is provided that the at least one blow-off opening delimits the first area wall and / or the second deletion section wall and / or the web in the height direction.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail with reference to an embodiment. The drawings are exemplary and are intended to illustrate the inventive idea, but in no way restrict it or even reproduce it.

Fig. 1

einen Kontaktkörper eines bekannten Stromschalters in einer Schnittansicht normal auf eine Schaltstrecke

Fig. 2

einen Kontaktkörper eines erfindungsgemäßen Stromschalters in einer Schnittansicht normal auf eine Schaltstrecke

Fig. 3

einen Kontaktkörper eines erfindungsgemäßen Stromschalters in einer Schnittansicht gemäß der Schnittlinie A-A in Fig. 2

Fig. 4

einen Kontaktkörper eines erfindungsgemäßen Stromschalters in einer Schnittansicht gemäß der Schnittlinie B-B in Fig. 2

Fig. 5

einen aufgeschnittenen Stromschalter mit mehreren Schaltkammern in axonometrischer Ansicht, wobei Schnittebenen C und D gekennzeichnet sind

Fig. 6

einen aufgeschnittenen Stromschalter mit mehreren Schaltkammern in axonometrischer Ansicht, wobei eine Schnittebene E gekennzeichnet ist

Fig. 7

in einer Schnittansicht analog zu Fig. 2 zwei Schaltkammern eines erfindungsgemäßen Stromschalters zum zweipoligen Schalten mit einer speziellen Anordnung von Permanentmagneten

Fig. 8

eine vergrößerte Ansicht des Details G in Fig. 7

Showing:

Fig. 1

a contact body of a known power switch in a sectional view normal to a switching path

Fig. 2

a contact body of a power switch according to the invention in a sectional view normal to a switching path

Fig. 3

a contact body of a power switch according to the invention in a sectional view along the section line AA in Fig. 2

Fig. 4

a contact body of a power switch according to the invention in a sectional view along the section line BB in Fig. 2

Fig. 5

a cut-open power switch with several switching chambers in axonometric view, wherein cutting planes C and D are marked

Fig. 6

a cut-open power switch with several switching chambers in axonometric view, wherein a sectional plane E is marked

Fig. 7

in a sectional view analogous to Fig. 2 two switching chambers of a current switch according to the invention for two-pole switching with a special arrangement of permanent magnets

Fig. 8

an enlarged view of the detail G in Fig. 7

WAYS FOR CARRYING OUT THE INVENTION

In Fig. 1 is a section through a contact body 2 of a known power switch shown. The contact body 2 has a switching chamber 4, in which a contact bridge 1 is arranged with a contact portion 7. The contact portion 7 is in Fig. 1 Rectangular and extends like the contact bridge 1 along a longitudinal direction 13 and a width direction 14. It should be noted, however, that of course other, in particular round shapes of the contact portion 7 are possible. The switching chamber 4 has a width X in the width direction 14, typically 8 mm to 9 mm.

More is in Fig. 1 to see an arc 3, along a switching path 18 (see. Fig. 3 ) between the contact portion 7 and the contact portion 8 of a contact piece 6, when the two contact portions 7, 8 are separated from each other under tension or load. Metal vapor formation of molten material of the contact portions 7, 8 and a subsequent dielectric breakdown occurs, with ionized metal vapor particles moving in accordance with the voltage applied to the contact portions 7, 8.

Finally, seen in the longitudinal direction 13 behind the switching chamber 4, a terminal space 26 is arranged. In the terminal space 26 protrudes a terminal 31 (see. Fig. 3 ), which is connected to the contact piece 6. The terminal 31 is used for fixing and connecting a conductor 33 on or with the contact piece 6, for which purpose a clamping screw 32 is used in the illustrated embodiment.

The in Fig. 1 shown section is substantially normal to said switching path 18; the sectional view of Fig. 3 shows a section through a current switch according to the invention according to the section line AA in Fig. 2 , where the Arrows indicate the line of sight. It is in Fig. 3 Also, a contact cover 28 recognizable, which can be pushed onto the contact body 2 and the contact piece 6 fixed by clamping.

Particularly with direct currents, depending on the strength of the current, destruction of the contact sections 7, 8 or even fires may occur if the arc 3 is not extinguished in time. In order to achieve the extinction of the arc 3, is in the in Fig. 2 shown embodiment of the contact body 2 of a power switch according to the invention, the switching chamber 4 executed asymmetrically. In this case, the switching chamber 4 is subdivided into a first switching chamber region 11 and an extinguishing section 12. The first switching chamber region 11 is bounded in the longitudinal direction 13 by a first region wall 30. Between the first switching chamber region 11 and the extinguishing section 12, the contact body 2 forms a web 10.

In addition, the in Fig. 2 shown contact body 2 a closed pocket 9, in which a permanent magnet 5 is arranged, the poles are preferably aligned in a direction normal to the switching path 18.

In order to use as many parts of the known power switch for the power switch according to the invention, the outer dimensions of the contact body 2 in Fig. 2 the same as those of the known contact body 2 in Fig. 1 , As in the contact body 2 of the Fig. 2 also the pocket 9 is accommodated for the permanent magnet 5, the extension of the switching chamber 4 in the width direction 14 is smaller - typically by 2 mm to 3 mm - than the width X of the known switching chamber 4 in Fig. 1 for better comparison also in Fig. 2 is drawn. Accordingly, the extension of the contact bridge 1 in the width direction 14 in Contact body 2 of the power switch according to the invention lower than that of the contact bridge 1 in Fig. 1 ,

In the switching chamber 4 of the power switch according to the invention, the web 10 is centered with respect to the extension of the contact bridge 1 in the width direction 14 or with respect to the extension of the contact portion 7 in the width direction 14, but also an off-center arrangement is conceivable. In the width direction 14, the contact bridge 1 is bounded by a contact bridge side edge 19, in the longitudinal direction 13 of a contact bridge edge 15. The contact bridge edge 15 and the contact bridge side edge 19 form a contact bridge corner 24, which projects into the extinguishing section 12.

The extinguishing section 12 has both in the longitudinal direction 13 and in the width direction 14 larger dimensions than the first switching chamber area 11. In this case, the deletion section 12 is delimited in the longitudinal direction 13 by a first deletion section wall 16 and a second deletion section wall 17. In the width direction 14, the deletion section is delimited by a third deletion section wall 20, which is also part of the web 10, and by a fourth deletion section wall 21.

Seen in the width direction 14, the first switching chamber region 11 is arranged downstream of the pocket 9 for the permanent magnet 5, and the extinguishing section 12 is arranged after the first switching chamber region 11 or after the web 10.

The first erase portion wall 16 abuts with the fourth erase portion wall 21, thereby forming a closed corner 22. In the same way, the fourth extinguishing section wall 21 with the second extinguishing section wall 17 and the second extinguishing section wall 17 with the third extinguishing section wall 20 form closed corners 22. Since only the imaginary extensions of the first erase portion wall 16 and the third erase portion wall 20 touch each other, not but the erase portion walls 16, 20 itself, an open corner 23 is formed by the first erase portion wall 16 and the third erase portion wall 20. Through this open corner 23, the contact bridge 1 projects with the contact bridge corner 24 into the extinguishing section 12.

This arrangement favors the deflection of the arc 3 in the erasing section 12. The distraction or widening of the length of the arc 3 is due to the Lorentz force acting on in the magnetic field of the permanent magnet 5 moving, ionized particles in the arc 3. Provided a given ("correct") current direction and thus movement direction of the ionized particles, the arc 3, as in Fig. 2 drawn, pushed into the deletion section 12. Due to the larger dimensioning of the extinguishing section 12 compared to the first switching chamber region 11, a correspondingly large length extension or deflection of the arc 3 in the extinguishing section 12 can be achieved.

In addition, the arc 3 in the erase portion 12 may come into contact with at least one of the erase portion walls 16, 17, 20, 21. Here, gas is split off from the material of the extinguishing section walls 16, 17, 20, 21 or the contact body 2, whereby the arc 3 is cooled and its rapid extinction is promoted. The gas delivery is dependent on the converted in the arc 3 power. In order to favor the gas delivery, there is the contact body 2, which is made in one piece with the web 10 and the extinguishing section walls 16, 17, 20, 21, of highly gassing material, preferably of a polyamide. If the arc 3 hits this material, mainly hydrogen is released.

The extent of the web 10 in the width direction 14 increases with the longitudinal direction 13, ie the web 10 widens in the longitudinal direction 13 in a V-shape. The V-shape facilitates that Arc 3, the shrinkage in the asymmetric extinguishing portion 12 of the switching chamber. 4

Basically, it should be noted that the extinction of the arc 3 by the interaction of permanent magnet 5 and extinguishing section 12 in the power switch of the invention even at low currents safely and almost independent of operation works.

If the current switch is used for switching rather weak alternating currents, the use of a permanent magnet 5 can be dispensed with in order to save costs, since in this case the arc 3 goes out at the next zero crossing of the current.

Only in a particularly preferred embodiment of, preferably equipped with a permanent magnet 5, power switch is provided as a pressure relief of the switching chamber 4 at least one exhaust port 27. The at least one exhaust opening 27 in this case connects the switching chamber 4 with the terminal space 26 located behind it, so that a pressure equalization between the switching chamber 4 and the terminal space 26 can take place. This in turn helps to extinguish the arc 3 more quickly by blowing it out. With regard to the size and positioning of the at least one exhaust opening 27 in the width direction 14 and a height direction 25 which is parallel to the switching path 18 and points from the contact bridge 1 to the contact piece 6, there are no fundamental restrictions.

Fig. 4 shows a section along the section line BB in Fig. 2 , where the arrows indicate the direction of view. In this sectional view, two exhaust ports 27 can be seen, one in the first area wall 30 of the first switching chamber area 11 and one in the second erasing section wall 17 of the erasing section 12, see also Fig. 3 , The two exhaust openings 27 limit the first area wall 30 and the second extinguishing section wall 17 in the vertical direction 25. Alternatively, for example, a single exhaust opening 27 is conceivable, which extends over the entire extent of the switching chamber 4 in the width direction 14 and in addition to the two in Fig. 4 recognizable exhaust openings 27 and an opening in the web 10 is formed.

The limited extent of the exhaust openings 27 in the height direction 25 promotes a nozzle effect, which contributes to the blowing out of the arc 3. This nozzle effect can also be increased by pointing to the exhaust openings 27 bevels 29. Correspondingly, in the first area wall 30 and in the second deletion section wall 17 seen in the height direction 25 bevels 29 are arranged in front of the respective outlet opening 27. In the exemplary embodiment shown, the chamfers 29 each extend over the entire extent of the exhaust openings 27 in the width direction 14.

In the sectional view of Fig. 3 the course of the chamfers 29 in the longitudinal direction 13 is particularly well visible. The second extinguishing section wall 17 extends according to the dotted line and tapers by means of the chamfer 29 along the height direction 25 and in the longitudinal direction 13 until the second extinguishing section wall 17 is finally delimited by the exhaust opening 27.

Fig. 5 shows an axonometric view of a cut-open power switch for two-pole switching with a total of eight switching chambers 4. On the contact body 2 is pushed against the height direction 25 of the contact cover 28, which closes the switching chambers 4 in the vertical direction 25. In the Fig. 5 marked sectional plane C corresponds to the sectional view of Fig. 2 , in the Fig. 5 marked sectional plane D of the sectional view of Fig. 3 , Finally shows Fig. 6 another axonometric view of the power switch off Fig. 5 , where a sectional plane E which is the sectional view of Fig. 4 equivalent.

Fig. 7 shows in a sectional view analogous to Fig. 2 two switching chambers 4, 4 'of a switching chamber pair of a current switch according to the invention for two-pole switching, wherein the two switching chambers 4, 4' have a common contact bridge 1. For switching chamber pair a pair of pockets is provided, consisting of pockets 9, 9 ', each of which is associated with one of the two switching chambers 4, 4' of the switching chamber pair. The two switching chambers 4, 4 'of the switching chamber pair and the two pockets 9, 9' of the pocket pair are mutually mirrored about a mirror plane 37, which is normal to the longitudinal direction 13, arranged. That is, the two switching chambers 4, 4 'of the switching chamber pair and the two pockets 9, 9' of the pocket pair are arranged one behind the other in the longitudinal direction 13. The pocket pair accommodates a permanent magnet pair, which consists of permanent magnets 5, 5 '.

In the pocket 9, the permanent magnet 5 can be seen, the poles are arranged in the plane and looking normal to the longitudinal direction 13 in a row. In the pocket 9 ', a permanent magnet 5' is arranged, whose poles are arranged exactly opposite. That the permanent magnet 5 'has opposite polarity to the permanent magnet 5.

Fig. 7 shows the situation with interruption of a direct current current 34. The arc 3, in the switching chamber 4 between the contact portion 7 of the contact bridge 1 and the contact portion 8 of the contact piece 8 (see. Fig. 3 ), points to the drawing plane of Fig. 7 , For the current direction 34 is a correct polarity of the permanent magnet 5 before, and it comes in the switching chamber 4 to a deflection 35 of the arc 3 in the extinguishing section 12th To illustrate the occurrence of the deflection of the arc in the erase section 12, shows Fig. 8 an enlarged view of the detail G in Fig. 7 in which field lines of the magnetic field of the permanent magnet 5 are drawn. Further, the magnetic flux density vector B is drawn at a point of the contact portion 7 and the vector of Lorentz force F resulting from the cross product of B with a plane vector velocity vector v of ionized particles of the arc 3 at that point.

According to the current direction 34, an arc 3 'in the switching chamber 4' out of the plane. For the current direction 34 is therefore a wrong polarity of the permanent magnet 5 'before, so that the arc 3', which originates in the switching chamber 4 'of a contact portion 7' of the switching bridge 1, not in a quenching section 12 'of the switching chamber 4' deflected or is pressed. Instead, there is a deflection 36 of the arc 3 'in a first switching chamber region 11' of the switching chamber 4 ', wherein between the first switching chamber region 11' and the extinguishing section 12 'is formed by a contact body 2 web 10' is arranged. However, since a deletion of the arc 3 in the erasing portion 12 of the switching chamber 4 and thus a reliable interruption of the contact occurs in the switching chamber 4, there is no overloading or damage to the components in the switching chamber 4 '.

LIST OF REFERENCE NUMBERS

1

Contact bridge

2

Contact body

3

Electric arc

4

switching chamber

5

permanent magnet

6

contact piece

7

Contact section of the contact bridge

8th

Contact section of the contact piece

9

Bag for the permanent magnet

10

web

11

First switching chamber area

12

erasing section

13

longitudinal direction

14

width direction

15

Contact bridge edge

16

First deletion section wall

17

Second extinguishing section wall

18

contact gap

19

Contact Bridge side edge

20

Third deletion section wall

21

Fourth deletion section wall

22

Closed corner

23

Open corner

24

Contact Bridge corner

25

height direction

26

terminal space

27

exhaust vent

28

Contact cover

29

bevel

30

First area wall

31

clamp

32

clamping screw

33

ladder

34

current direction

35

Deflection of the arc with correct polarity of the permanent magnet

36

Deflection of the arc with wrong polarity of the permanent magnet

37

mirror plane

3 '

Arc in the switching chamber of a switching chamber pair

4 '

Switching chamber of a switching chamber pair

5 '

Permanent magnet of a permanent magnet pair

7 '

Contact section in the switching chamber of a switching chamber pair

9 '

Bag of a bag pair

10 '

Bar in a switching chamber of a switching chamber pair

11 '

First switching chamber area of a switching chamber of a switching chamber pair

12 '

Extinguishing section of a switching chamber of a switching chamber pair

X

Width of the switching chamber of a known power switch

v

Velocity vector of an ionized particle of the arc

B

Magnetic flux density

F

Lorentz force

Claims (23)

Power switch, preferably DC power switch, comprising a contact body (2) with at least one switching chamber (4), in which a contact portion (7) of a contact bridge (1) extending along one of the contact bridge (1) in the at least one switching chamber ( 4) pointing longitudinal direction (13) and a transverse to the longitudinal direction (13) extending width direction (14), and a contact portion (8) of a contact piece (6) are arranged, wherein when opening a switching path (18) parallel to a extending from the contact bridge (1) to the contact piece (6) height direction (25), between the contact portions (7, 8) of the contact bridge (1) and the contact piece (6) under load an arc (3) is formed, characterized in that the at least one switching chamber (4) has an extinguishing section (12) in which the arc (3) is deflectable, that the extinguishing section (12) in the longitudinal direction (13) of a first extinguishing section wall (16) and a the second erasing portion wall (17) is limited so that the erasing portion (12) is bounded in the width direction (14) by a third erasing portion wall (20) and a fourth erasing portion wall (21), and that the first (16), second (17), third (20) and fourth erase section wall (21) form three closed corners (22) and an open corner (23). A power switch according to claim 1, characterized in that the open corner (23) is formed by the first (16) and third erase section wall (20). Power switch according to one of claims 1 to 2, characterized in that the contact bridge (1) in the longitudinal direction (13) of a contact bridge edge (15) is limited and that in the longitudinal direction (13) seen the contact bridge edge (15) between the first (16) and the second extinguishing section wall (17) is arranged. Power switch according to one of claims 1 to 3, characterized in that the contact bridge (1) in the width direction (14) by a contact bridge side edge (19) is limited and that seen in the width direction (14), the contact bridge side edge (19) between the third (20) and the fourth erase portion wall (21). Power switch according to one of Claims 1 to 4, characterized in that the contact bridge (1) projects through the open corner (23) into the extinguishing section (12). Power switch according to claim 5, characterized in that the contact bridge (1) projects with a contact bridge corner (24) through the open corner (23) into the extinguishing section (12), wherein the contact bridge corner (24) through the contact bridge edge (15) and the Contact bridge side edge (19) is formed. Power switch according to one of claims 1 to 6, characterized in that the contact body (2) at least one pocket (9) for receiving a permanent magnet (5) to deflect the arc (3) into the extinguishing section (12), wherein the at least one pocket (9) is formed separately from the at least one switching chamber (4). Power switch according to one of claims 1 to 7, characterized in that the at least one pocket (9) extends parallel to the switching path (18). Power switch according to one of claims 1 to 8, characterized in that in the at least one pocket (9) a permanent magnet (5) is arranged, wherein the poles are arranged along a direction transverse to the switching path (18). Power switch according to one of claims 1 to 9, characterized in that the at least one switching chamber (4) has a recess of the contact body (2) running, first switching chamber region (11) in the longitudinal direction (13) of a first area wall (30) is limited, and that between the first switching chamber region (11) and the extinguishing section (12) from the contact body (2) formed web (10) is arranged. Power switch according to claim 10, characterized in that the extinguishing section (12) in the width direction (14) and / or in the longitudinal direction (13) has larger dimensions than the first switching chamber region (11). Power switch according to one of claims 10 to 11, characterized in that the web (10) has a cross section which widens in the longitudinal direction (13) V-shaped. Current switch according to one of claims 10 to 12, characterized in that the web (10) in the width direction (14), preferably centrally to the extension of the contact portion (7) of the contact bridge (1) in the width direction (14) centrally to the extension of the contact bridge (1) in the width direction (14 ) is arranged. Power switch according to one of claims 1 to 13, characterized in that the contact body (2) is made in one piece and made of a polyamide. Power switch according to one of claims 1 to 14, characterized in that the contact body (2) further comprises at least one terminal space (26), which is arranged in the longitudinal direction (13) behind the at least one switching chamber (4), and that at least one exhaust opening (27) is provided, which connects the at least one switching chamber (4) with the at least one terminal space (26). Power switch according to claim 15, characterized in that in the width direction (14) and / or in the height direction (25), the extension of the at least one exhaust opening (27) is less than or equal to the extent of the at least one switching chamber (4). Power switch according to one of claims 15 to 16, characterized in that the at least one blow-off opening (27) in the first area wall (30) and / or in the second extinguishing section wall (17), seen in the longitudinal direction (13) behind the first extinguishing section wall ( 16) is arranged, and / or in the web (10) is arranged. Power switch according to one of Claims 15 to 17, characterized in that the first area wall (30) and / or the second extinguishing section wall (17) and / or the web (10) has a bevel (29) pointing towards the at least one exhaust opening (27). having. Power switch according to claim 18, characterized in that the chamfer (29) extends over the entire extent of the at least one exhaust opening (27) in the width direction (14). Power switch according to one of claims 15 to 19, characterized in that the at least one exhaust opening (27), the first area wall (30) and / or the second deletion section wall (17) and / or the web (10) in the height direction (25) limited. Power switch according to one of claims 7 to 20, characterized in that for bipolar switching at least one switching chamber pair is provided, which consists of two switching chambers (4, 4 '), preferably with a common contact bridge (1), that a pocket pair is provided which consists in each case of a pocket (9, 9 ') to each switching chamber (4, 4') of the switching chamber pair, and that a pair of permanent magnets is provided, each consisting of a permanent magnet (5, 5 ') arranged in each pocket (9 9' ) of the pocket pair, and that the poles of one permanent magnet (5) of the permanent magnet pair are arranged differently than the poles of the other permanent magnet (5 ') of the permanent magnet pair. Power switch according to claim 21, characterized in that the poles of one permanent magnet (5) of the permanent magnet pair are arranged opposite to the poles of the other permanent magnet (5 ') of the permanent magnet pair. Power switch according to one of claims 21 to 22, characterized in that the two switching chambers (4, 4 ') of the switching chamber pair and the two pockets (9, 9') of the pocket pair in the longitudinal direction (13) seen one behind the other, preferably to a normal on the Mirrored longitudinal plane (13) mirror plane (37) mirrored, are arranged.

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