EP0982748B1 - Switch assembly and process for producing same - Google Patents

Description

The invention relates to a switching arrangement, in particular for Circuit breakers, such as those in power plants, substations and other electrical energy supply facilities for and switching off operating and overcurrents as well as a process for their production.

State of the art

Generic switching arrangements are known in which especially parts of contact pieces on which the Base points of the arc that forms when switching lie, made of particularly erosion-resistant material. Such material is usually made by sintering one Mixture of metal powders, e.g. B. tungsten as high melting point and copper as lower melting point Component manufactured. This sintered material is pretty difficult to process. Above all, it is extremely brittle and can only be formed using machining processes. It is also not weldable in the usual way and can with other materials only by means of proportionality complicated procedures can be connected as by Back casting with copper, friction welding, Flash butt welding or electron beam welding or by soldering, which, however, is a proportionate connection low strength or removable by a Screw connection, which however is a complicated machining requires. The installation of fire-resistant parts or Cladding is therefore generally expensive.

Because the erosion-resistant material is practically not deformable is the possibilities of shaping one Base body, which with a burn-resistant Cladding to be provided is very limited. Because of the Brittleness of the material it is also not possible flexible parts with a fire-resistant cladding Mistake. For these reasons, one is usually satisfied with it, e.g. B. tips of switching pins, burn rings and similarly simple parts made of fire-resistant material use. Other parts of the arc room and on the same Subsequent areas, which also the one at a Are exposed to hot gases remain unprotected.

From the patent application EP 0 800 191 A2 one as Circuit breakers named generic switching arrangement known, which has an arc room and two fixed Has switching pieces. The two contact pieces are in the Switch-on position via a bridging contact with each other connected, in the off position they are apart Cut. Become part of the surfaces of the arc room made of fire-resistant material.

From patent application EP 0 428 740 A1 is a erosion-resistant contact material known, which successively in several layers on a contact body is applied. This contact material shows comparatively low melting points so that for circuit breakers, for use in the medium and high voltage range are provided, cannot be used or can only be used to a limited extent.

Presentation of the invention

The invention has for its object a Specify generic switching arrangement that is simple How to manufacture and a process for their Production. This task is characterized by the characteristics of the Claim 1 and claim 22 solved.

The advantages achieved by the invention are next to the facilitated manufacture of the switching arrangement, in particular of their fire-resistant parts, especially in that the possibility of fire-resistant protective layers attached, is significantly expanded. So can protective layers according to the invention on almost any molded parts, with variable thickness and self Composition can be applied. Thanks to their bigger ones Protective layers can also be flexible on flexible, in particular attached elastically deformable parts become essential without losing their flexibility would be affected or the risk of cracking in the protective layer would exist.

Due to the possibility of largely any surface erosion-resistant protective layers according to the local Applying requirements becomes essential Restrictions on the formation of circuit arrangements, in particular the contact pieces are eliminated and can Executions that are otherwise or only implemented would be of limited practical use. The freedom of action in Switch design is significantly expanded.

Brief description of the drawings

Fig. 1

einen axialen Längsschnitt durch einen Leistungsschalter mit erfindungsgemässen Schaltanordnungen, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 2a

vergrössert einen axialen Längsschnitt durch eine Abbrandschaltanordnung des Leistungsschalters nach Fig. 1,

Fig. 2b

vergrössert und leicht abgewandelt ein Detail aus der Abbrandschaltanordnung nach Fig. 2a,

Fig. 3a

schematisch und vergrössert einen Ausschnitt aus einer Nennstromschaltanordnung des Leistungsschalters nach Fig. 1 radial von aussen, in Einschaltstellung

Fig. 3b

in kleinerem Massstab einen Schnitt längs B-B in Fig. 3a,

Fig. 3c

vergrössert einen Ausschnitt aus Fig. 3b,

Fig. 4a

einen axialen Längsschnitt durch eine weitere erfindungsgemässe Schaltanordnung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 4b

vergrössert einen axialen Längsschnitt durch einen Teil der Abbrandschaltanordnung nach Fig. 4a, entsprechend einem Schnitt längs B-B in Fig. 4c,

Fig. 4c

einen Schnitt längs C-C in Fig. 4b,

Fig. 5a

einen axialen Längsschnitt durch eine weitere erfindungsgemässe Schaltanordnung in Einschaltstellung,

Fig. 5b

die Schaltanordnung von Fig. 5a in Ausschaltstellung,

Fig. 5c

vergrössert einen axialen Längsschnitt durch einen Teil der Abbrandschaltanordnung nach Fig. 5a, 5b, entsprechend einem Schnitt längs C-C in Fig. 5d und

Fig. 5d

einen Schnitt längs D-D in Fig. 5c.

The invention is explained in more detail below with reference to drawings, which only show exemplary embodiments. Show it

Fig. 1

3 shows an axial longitudinal section through a circuit breaker with switching arrangements according to the invention, left in the on position, right in the open position,

Fig. 2a

1 enlarges an axial longitudinal section through an erosion switching arrangement of the circuit breaker according to FIG. 1,

Fig. 2b

enlarged and slightly modified a detail from the erosion switching arrangement according to FIG. 2a,

Fig. 3a

schematically and enlarged a section of a rated current switching arrangement of the circuit breaker according to FIG. 1 radially from the outside, in the closed position

Fig. 3b

on a smaller scale a section along BB in Fig. 3a,

Fig. 3c

enlarges a detail from FIG. 3b,

Fig. 4a

3 shows an axial longitudinal section through a further switching arrangement according to the invention, on the left in the on position, on the right in the off position,

Fig. 4b

4a, corresponds to a section along BB in FIG. 4c,

Fig. 4c

3 shows a section along CC in FIG. 4b,

Fig. 5a

3 shows an axial longitudinal section through a further switching arrangement according to the invention in the switched-on position,

Fig. 5b

5a in the off position,

Fig. 5c

5a, 5b, corresponding to a section along CC in FIGS. 5d and

Fig. 5d

a section along DD in Fig. 5c.

Ways of Carrying Out the Invention

The left in Fig. 1 in the on position, right in Circuit breaker shown in the open position, which z. B. can be used as a generator switch Housing 1 on that around a switching axis 2 essentially is rotationally symmetrical with an upper housing part 3 and a lower housing part 4, both made of metal, which by a cylindrical middle housing part 5 made of insulating Material are connected. The housing parts 3, 4 are each with the opposite live connections of the Circuit breaker connected.

At the level of the middle housing part 5 there is an outside Rated current switching arrangement arranged, each on the upper housing part 3 and lower housing part 4 subsequent, spaced apart in the axial direction revolving fixed nominal current contacts, an upper one fixed nominal current contact 6 and a lower one includes fixed current contact 7 and a Movable nominal current contact 8 with in the circumferential direction successive, in the on position each Distance between the fixed nominal current contacts 6, 7 bridging contact fingers. The mobile Current contact 8 is with a not shown Switching drive connected, through which it is in axial Direction between the switch-on position, in which he the Gap between the upper fixed nominal current contact 6 and bridges the lower fixed nominal current contact 7 and the switch-off position, in which it is from the upper fixed nominal current contact 6 is spaced, is movable.

The upper housing part 3 is through a horizontal partition 9 completed down. It carries the fixed part a burn-up switching arrangement 10. In a central opening the partition 9 is a contact tulip as the first switching piece 11 attached with several in the circumferential direction successive, diagonally down and against the Switching axis 2 directed, separated by slots elastic contact fingers. The contact tulip 11 opposite is a nozzle 12 surrounding the switching axis 2 made of electrical insulating material arranged in the shape of a funnel constricting upwards. In an im lower housing part 4 arranged slide guide 13, which also establishes a good electrical connection as a second switching piece axially by means of the switching drive movable switching pin 14 mounted in the Switch-on position protrudes into the contact tulip 11 and from it Contact fingers is touched on the outside. The same will happen slightly elastically deformed so that it is a relatively high contact pressure on the switching pin 14 exercise. The sliding guide 13 is on a partition 15 anchored, which the lower housing part 4 upwards concludes. In a central opening of the partition 15 the nozzle 12 is attached.

In the off position, the switching pin 14 is down drawn so that its tip is below the nozzle 12. Is between the contact tulip 11 and the switching pin 14 then an arc room 16, in which when switched off there is an arc 17 between said switching elements has trained. The arc room 16 is one contiguous annular heating volume 18 surround the with it through the contact tulip 11 from the nozzle 12 separating gap, the circumferential blow slot 19th forms, is connected. The heating volume 18 is through on the outside a peripheral wall 20 made of insulating material completed. On the partition 15, several, for. B. four distributed over the circumference blowing cylinder 21 from Switchable actuatable blow piston 22 arranged, the each connected to the heating volume 18 via blowing channels 23 are. In the mouths of the blowing channels 23 in the heating volume 18 check valves 24 are installed.

The movable nominal current contact 8 and the switch pin 14 pulled down. The mobile Rated current contact 8 is fixed from the top Rated current contact 6 separated so that the current from the Rated current switching arrangement on the erosion switching arrangement commutated. When the switching pin 14 is separated from the Contact tulip 11, the arc 17 is then drawn, which, when the switching pin 14 has reached the switch-off position, through the nozzle 12, the contact tulip 11 with the tip of the Switch pin 14 connects. By the arc 17 outgoing heat and the pumping action of the blowing cylinder 21, whose piston 22 together with the switching pin 14 down were moved, a high pressure builds up in the heating volume 18 on which a strong flow of extinguishing gas through the Contact tulip 11 and the nozzle 12 generated and the arc 17 clears at a subsequent current zero crossing.

The contact tulip 11 (Fig. 2a) as the first contact of the Burn-up switching arrangement consists of individual contact fingers 25, which surround the switching axis 2. They are minor elastically deformable and their tips are in the Switch-on position through contact with switching pin 14 slightly deflected outwards, which is sufficient Ensures contact pressure. The contact tulip 11 has one Base body 26 made of copper or another suitable Material on whose surface in the area of the contact finger 25 lies behind the surface according to the final dimension and which in said area a fire-resistant protective layer 27 which fills up the difference to the final dimension. The The protective layer 27 is produced by the other well-known techniques of the technical field Plasma spraying. Their composition can largely be that of correspond to conventional erosion-resistant material.

The switching pin 14, the second contact piece of the Burn-up switching arrangement, consists of a z. B. from a Copper alloy or other known for the purpose suitable material produced base body 28, the Surface at the tip and in the adjoining one The area behind the surface is the final dimension by a turn on the base body 28 Protective layer 29 applied by plasma spraying becomes. The protective layer 29 forms at the top of the Switch pin 14 a relatively massive cap and ends in a slightly thinner coat. According to Fig. 2a the jacket extends over the contact area, which in the switched-on position by the contact fingers 25 the contact tulip 11 is touched.

In Fig. 2b is a slightly different version of the Protective layer 29 shown, according to which it before this Contact area ceases. Because the conductivity of the Protective layer 29 is less than that of base body 28, the contact resistance is lower and the Commutation of the current on the erosion switching arrangement facilitated. Since in the present described Abbrandschaltanordnung the contact tulip 11 at the Switching off of hot gases is recommended it, its protective layer at least on the front area and stretch the inside. When switching pin 14 are the areas slightly further behind the top on the other hand, little burden and generally do not require anyone Protective layer. In switching arrangements in which the rear parts of both contact blocks located in the front areas are not the protective layers are conceivable not to extend on both sides to the contact area and thereby further reduce the contact resistance.

The formation of the protective layers 27, 29 can after Extent and thickness very precisely on the resulting from the Load on the switching elements resulting requirements can be set. In general, it is sufficient that Separation areas of the contact pieces, on which they are located in the Disconnect disconnection from each other and where first Form arc base points, as well as each other in the Switch-off position opposite front areas, between to which the arc burns and which burns through Radiation and hot gases are particularly heavy, to be provided with protective layers. However, it is quite possible and possibly useful, other parts of the Arcing space such as wall sections by means of Plasma-sprayed, erosion-resistant protective layer protect from gases heated by the arc.

The circuit breaker's rated current switching arrangement according to 1 comprises the upper fixed nominal current contact 6 as the first contact and the movable nominal current contact 8 as a second contact. The latter has (Fig. 3a, b) several hundred over the scope of the nominal current switching arrangement distributed parallel contact fingers, which in groups of several contact fingers grouped together via one Pressure spring 30 on an axially displaceable carrier ring 31 are stored. It follows several groups of Contact fingers 32 each a group of slightly longer Power fingers 33. The upper fixed current contact 6 is designed as a contact ring 34 on the outside thereof the contact fingers 32 and the power fingers 33 in the Switch on position.

The power fingers 33 again consist (see FIG. 3c) a base body 35 which on the contact ring 34 facing a crust-resistant protective layer 36 has, which in turn by means of plasma spraying is applied. The same applies to the contact ring 34, a protective layer 37 on its switch-off edge has, which is slightly pulled up on the outside is. The contact ring 34 is located above the protective layer 37 a silver-plated contact zone 38, which in the Switch-on position not only by the power fingers 33, but also from the somewhat shorter contact fingers 32, which are also silver-plated is touched. The Rated current switching arrangement has a very high Continuous current carrying capacity and a very low one Contact resistance.

When switching off, the contact fingers are released first 32 from the contact ring 34, whereupon the current on the Power finger 33 commutates. If this also from Contact ring 34 are disconnected, it comes before the current completely commutated to the erosion switching arrangement, for Arcing between the separation areas at the ends the power finger 33 and on the edge of the contact ring 34, the protective layers 36 and 37 ensure that the burns up within narrow limits.

The following are two more examples of Burn-up switching arrangements are shown, in which of the special possibilities opened up by the invention Use is made. In particular, they include Switching elements used for the purpose of electromagnetic Forces to increase contact pressure are shaped and complex z. T. are flexible, but with a Burn-resistant largely corresponding to requirements Protective layer are provided. They specifically point out Switch pins on with one each at the top then a protective layer on the outside having resistant section, which in two or more parallel or anti-parallel partial conductors disintegrate.

The left in Fig. 4a in the on position, right in Switched off position shown second inventive Embodiment of a burn-up switching arrangement of a Circuit breaker, which, for. B. in the circuit breaker Fig. 1 in place of that and shown in Fig. 2a, b first embodiment of an inventive Abbrandschaltanordnung can occur - the corresponding Parts are therefore designated with the same reference symbols -, points in turn around a switching axis 2 rotationally symmetrical housing made of insulating material annular heating volume 18, which is a first switching piece, which is connected to the first electrical connection and surrounds a second contact piece. The first contact is the first attached to the underside of the partition 9 Switch ring 39 formed, the second contact piece as Switch pin 14. The first switching ring 39 at a distance opposite is one on the top of the partition 15 attached second switching ring 40 arranged such that arranged between them concentrically to the switching axis 2 Switching rings is an arc room 16, which with the Heating volume 18 via a circumferential blow slot 19 connected is.

The switching pin 14 is further down from a sliding bell 41 surround which, like the second switching ring 40 with the second electrical connection is connected. The Switch pin 14 has a central mandrel 42 trained carrier, in the tip of a cap 43 erosion-resistant material is screwed in, which is a sleeve 44 made of highly conductive, resilient material, in particular clamps a ring 45 at the front end thereof. Of the Ring 45 goes to a group of eight on the same level Switch pin 14 arranged, separated by slots elongated contact fingers 46, which, the mandrel 42 approximately surrounding parallel, protrude to the rear. The mandrel 42 is from the cap 43 to beyond the ends of the contact fingers 46 surrounded by an insulating sleeve 47 with which a thicker insulating ring 48 overlaps.

In the on position they touch just before the ends the contact finger 46 lying contact surfaces 49 the Inside of the first switching ring 39. The switching pin 14 largely fills its opening, as does that of the second switching rings 40, in which the insulating ring 48 lies. The current path runs from the first switching ring 39 the contact surfaces 49 into the contact fingers 46 and through the same to the ring 45 and further through the mandrel 42 and over the sliding bell 41. The one surrounded by the contact fingers 46 the foremost part of the mandrel 42 forms a partial conductor, the one to the currents in the also partial conductor forming contact fingers 46 with which he through the ring 45th electrically connected, anti-parallel current wearing. Because of the electromagnetic Repulsion between the mandrel 42 and the contact fingers 46 the latter are spread apart and their contact surfaces 49 pressed against the inside of the first switching ring 39. The thus generated contact forces, as well as those of them opposite contact lifting forces, the stronger, ever greater the amperage is what is amperage independent Force compensation.

Moves during the first phase of the opening movement that is in contact with the first switching ring 39 Area of the switching pin 14 against the cap 43 so that the length of the anti-parallel current paths is proportional decreases rapidly and with them the contact forces. If the Switching pin 14 is pulled out of the first switching ring 39, forms between the latter and the cap 43 Electric arc. When the cap 43 has the second switching ring 40 happens, the arc base jumps up from the same over this, so that the arc then between the first Switch ring 39 and the second switch ring 40 burns. He will blow out of the heating volume 18 and at one following zero crossing of the current deleted.

The first switching ring 39, the second switching ring 40 and the Cap 43 consist of simple, rigid parts acts from solid, in a known manner by sintering manufactured fire-resistant material. However, you could also, similar to the tip of the switching pin according to Fig. 2b, each from a base body from z. B. one Copper alloy exist, the one by plasma spraying applied protective layer made of fire-resistant material wearing.

The more complicated shaped flexible sleeve 44 is anyway again made up of a base body 50 and one of them Protective layer 51 forming the outer surface erosion-resistant material caused by plasma spraying the base body 50 was applied. The base body 50 consists of an elastic material of good Conductivity. The protective layer 51 is sufficient flexible to the elastic deformations to which the Contact fingers 46 are subjected to follow. That's the way it is possible, not only the particularly stressed parts like that Tip of the switching pin 14, the first switching ring 39 and the second switching ring 40, on which Form arc base points to protect, but the entire outside of one of the cap 43, the sleeve 44 and the inner front part of the mandrel 42 is formed resistant portion of the switching pin 14 by escaping hot gases is also heavily loaded.

In the third shown in Figures 5a-d Embodiment according to the invention Burn-up switching arrangement, which is the second of the rest Embodiment corresponds, the attraction between parallel flows to apply the required Contact forces exploited. The switching pin 14 instructs two the end of the carrier, which in turn is designed as a mandrel 42 adjoining elastically flexible parallel extensions 52a, b which are separated by a slot 53. On his Each of the extensions 52a, b has a contact piece 54a at the end or 54b with a contact surface 49 for contacting the Inner surface of the first switching ring 39 with which he is connected via a connecting piece 55a or 55b in such a way that each of the contact pieces 54a, b is opposite to the respective one Extension 52a or 52b with respect to a switching pin axis, which coincides with the switching axis 2, offset by 180 ° is. The connectors 55a, b are short, one half-gear screw sections formed.

The contact pieces 54a, 54b are separated from each other by a Continuation 53 'of the slot 53 separately. Taken together, they have a polygonal cross-section, in the example a twelve-sided one on. The first contact piece 54a runs into the hemispherical tip of the switching pin 14. Of this Apart from the difference, they each correspond to one Extension 52a or 52b, a connecting piece 55a or 55b and a contact piece 54a or 54b existing parts of the Switch pin 14, which is made in one piece with the mandrel 42 are made of highly conductive, resilient material, Completely.

In the switch-on position shown in FIG. 5a, in which the contact pieces 54a, b by contact with the first switching ring 39 pressed slightly against each other and the Extensions 55a, b are spread apart accordingly, see above that the contact surfaces 49 already by elastic Restoring forces against the inside of the first switching ring 39 are pressed, the current path runs over this and through the contact surfaces 49 into the contact pieces 54a, b the same and the connecting pieces 55a, b, the extensions 52a, b and a section of the mandrel 42 and further over the Sliding tulip 41. The second switching ring 40 touches the Switch pin 14 is not. The two are relatively long Extensions 52a, b carry parallel currents and are thereby drawn together. The ones associated with them opposite contact pieces 54a, b offset by 180 ° thereby pushed apart and their contact surfaces 49 thereby pushing harder against the inside of the first Switch rings 39. Due to the polygonal cross section of the It touches the switching pin 14 in the area of the contact surfaces 49 the first switching ring 39 always in at least four places.

Shortly after the switch-off movement begins, touch the Contact pieces 54a, b also the second switching ring 40 and partially close the current path described above short. This also reduces the electromagnetic Attraction between extensions 52a and 52b and likewise those caused by it Contact forces. The further withdrawal of the switching pin 14 will not hindered by excessive friction. If the tip of the switching pin 14 from the opening of the first Switching rings 39 is pulled, forms between them Share an arc. If the tip of the switching pin 14 then the opening of the second switching ring 40 happens the arc commutates on it. Then it burns between the first switching ring 39 and the second switching ring 40 and is blown from the heating volume 18 and at one following current zero crossing deleted.

The first switching ring 39 and the second also exist here Switch ring 40 in a conventional manner from solid sintered erosion-resistant material. The switching pin 14 however, again consists of a base body 56 highly conductive elastic material in the range of the connectors 55a, b and those connected to them Contact pieces 54a, b formed in two partial conductors decaying resistant section through Plasma-sprayed, erosion-resistant protective layer 57 carries. It is in the range of through the Arc base particularly heavily loaded tip of the Switch pin 14 relatively thick and to the Outer surfaces of the contact pieces 54a, b and Connecting pieces 55a, b are made somewhat thinner. It is also conceivable, the hemispherical tip of the switching pin as a cap made of solid, sintered in a conventional manner fire-resistant material. In any case the entire outside of the complex shaped resistant Section of the switching pin 14 on which a part of escaping hot gases from which Surface of the erosion-resistant protective layer 57 is formed.

Because the application of a fire-resistant protective layer is significantly facilitated by the invention, it is practical, not only parts of switching pieces, but also others by the hot that arises when switching off Protect parts exposed to gases. So the circulating Wall surfaces of the adjoining the burn-off rings 39, 40 widening exhaust openings also from through Protective layers 58, 59 produced on plasma spraying Base bodies 60, 61 of the partitions 9, 15 are formed.

For the application of a more burn-resistant Protective layer used on a base body Plasma spraying is characterized by a high electric field a suitable plasma gas generates a plasma in which introduced a powder mixture by means of a conveying gas becomes. The powder mixture is liquefied and together with the gas through the electric field against the body accelerated and sprayed onto its surface where it forms a layer that quickly solidifies. to Plasma spraying is avoided by oxidation preferably carried out under vacuum.

The protective layers produced in this way have a Burn-up resistance to that of conventional ones manufactured fire-resistant parts is not inferior. she are also relatively flexible, so that any Deformations of the base body are not hindered. The Thickness of the layer applied by plasma spraying precisely and variably adjustable. Postprocessing by Machining is therefore usually only minor Extent especially for setting the Surface properties required. Most of all, it is often relevant, the surface roughness by grinding or Reduce polishing. Removing bigger ones Material volumes e.g. B. by milling is also possible, however mostly not necessary.

As for the composition of the powder mixture, which for the production of the erosion-resistant protective layer on the Base body is used in each case and then the Composite corresponds to the same, there are many Possibilities. It can largely depend on the respective Needs to be matched. Usually you will like with known sintered erosion-resistant materials provide a mix that is good Burn-off resistance a high-melting component and a lower melting component, which by evaporation to Cooling contributes, contains. In most cases, a Proportion of refractory metals with a melting point of at least 2,000 ° C such as W, Mo or Ir of at least 10% (wt.), Preferably at least 50% (wt.) Favorable, while as lower melting materials with a Melting point below 2,000 ° C Cu, Ag, Ti, Fe can be used can. It has proven itself very well as with conventional sintered erosion resistant material a mixture of Tungsten and copper, especially with approx. 80% (wt.) Or 20% (wt.). Other copper alloys, especially with Mo are cheap.

Many materials are also used for the base body Question that will be chosen depending on requirements, like Cu, Ag, Fe, steel, Al or if high conductivity and at the same time Elasticity of the material is required, also flexible Copper alloy such as CuBe, CuCr or CuCrZr.

LIST OF REFERENCE NUMBERS

1

casing

2

switching axis

3

upper housing part

4

lower housing part

5

middle housing part

6

Upper fixed nominal current contact

7

lower fixed nominal current contact

8th

Movable nominal current contact

9

partition wall

10

consumable

11

Contact tulip

12

jet

13

slide

14

switch Probe

15

partition wall

16

Arcing area

17

Electric arc

18

heating volume

19

blow slot

20

wall

21

puffer cylinder

22

puffer

23

blow

24

check valve

25

contact fingers

26

Basic body of the contact tulip 11

27

Protective layer of the contact tulip 11

28

Basic body of the switching pin 14

29

Protective layer of the switching pin 14

30

pressing spring

31

support ring

32

contact fingers

33

performance finger

34

contact ring

35

Basic body of the power finger 33

36

Protective layer of the power finger 33

37

Protective layer of the contact ring 34

38

Contact zone of the contact ring 34

39

first switching ring

40

second switching ring

41

sliding tulip

42

mandrel

43

cap

44

shell

45

ring

46

contact fingers

47

insulating sleeve

48

insulating ring

49

Contact surfaces of the contact fingers 46

50

Basic body of the sleeve 44

51

Protective layer of the sleeve 44

52a, b

projections

53

Slot between the extensions 52a, 52b

53 '

Slot between the contact pieces 54a, 54b

54a, b

contacts

55a, b

connectors

56

Basic body of the switching pin 14

57

Protective layer of the switching pin 14

58

Protective layer of the partition 9

59

Protective layer of the partition 15

60

Basic body of the partition 9

61

Basic body of the partition 15

Claims (22)

1. Switching arrangement having at least one arcing chamber (16) and at least one first switching contact and a second switching contact, which are arranged in the said arcing chamber in such a manner that they can move with respect to one another between a switched-on position, in which they are in contact with one another, and a switched-off position, in which they are isolated from one another, at least part of the surfaces in the arcing chamber (16) being formed by material which is resistant to contact erosion, characterized

   in that at least some of the material which is resistant to contact erosion is present in the form of a protective layer (27, 29, 36, 37, 51, 57, 58, 59) which has been applied to a base body (26, 28, 35, 50, 56, 60, 61) by plasma spraying,

   in that the protective layer (27, 29, 36, 37, 51, 57, 58, 59) contains at least one high-melting component with a melting point of at least 2000°C,

   in that the protective layer (27, 29, 36, 37, 51, 57, 58, 59) contains at least one lower-melting component with a melting point of below 2000°C.
2. Switching arrangement according to Claim 1, characterized

   in that at least the isolating areas of the first switching contact and of the second switching contact, at which the first switching contact and the second switching contact are isolated from one another when the arrangement moves from the switched-on position to the switched-off position, each have a protective layer, (27, 29, 36, 37, 51, 57).
3. Switching arrangement according to Claim 1 or 2, characterized

   in that at least the front area of at least the first switching contact or of the second switching contact, which front area, in the switched-off position, faces toward the respective opposite switching contact, has a protective layer (27, 29, 36, 37, 57).
4. Switching arrangement according to Claim 2 or 3, characterized

   in that the contact area of at least the first switching contact or the second switching contact, which contact area, in the switched-on position, is in contact with the opposite switching contact, does not have the protective layer (29).
5. Switching arrangement according to one of Claims 1 to 4, characterized

   in that it is designed as an arcing switch arrangement, the first switching contact of which is designed as a switching pin (14) which can be displaced along a switching axis (2) and the tip of which has a protective layer (29, 57).
6. Switching arrangement according to Claim 5, characterized

   in that at least part of the outside of a resistant section of the switching pin (14), which section adjoins the tip of the switching pin (14), is likewise formed by a protective layer (29, 51, 57).
7. Switching arrangement according to Claim 6, characterized

   in that the resistant section of the switching pin (14) comprises at least two separate, parallel or antiparallel conductor elements, at least one of which forms part of the outside which is covered by a protective layer (51, 57).
8. Switching arrangement according to Claim 7, characterized

   in that the conductor elements are designed as contact fingers (46) which in the area of the tip of the switching pin (14) are attached to a central support, project freely towards the rear and surround the support.
9. Switching arrangement according to Claim 7, characterized

   in that the conductor elements adjoin extensions (52a, 52b) which project parallel to one another and towards the front, and comprise connection pieces (55a, 55b), which form approximately half a thread turn, and adjoining contact pieces (54a, 54b).
10. Switching arrangement according to one of Claims 5 to 9, characterized

    in that the second switching contact is designed as a tulip contact (11) with a plurality of contact fingers (25) which surround the switching axis (2) and at least the tips of which each have a protective layer (27).
11. Switching arrangement according to Claim 10, characterized

    in that the contact fingers (25) each have a protective layer (27) at least on their insides.
12. Switching arrangement according to one of Claims 1 to 4, characterized

    in that it is designed as a rated-current switching arrangement, the second switching contact of which comprises a ring of contact fingers which can be displaced along a switching axis (2), surround the said axis and at least some of which are designed as power-switch fingers (33), the tips of which each have a protective layer (36) in the side facing towards the first switching contact.
13. Switching arrangement according to Claim 12, characterized

    in that the second switching piece is designed as a contact ring (34) which surrounds the switching axis (2) and, at its switched-off-side edge, has a protective layer (37) at least at the areas which interact with the power-switch fingers (33).
14. Switching arrangement according to one of Claims 1 to 13, characterized

    in that at least one wall surface which delimits the arcing chamber (16) or an area which is connected to the latter is formed by a protective layer (58, 59).
15. Switching arrangement according to Claim 1, characterized

    in that the high-melting component is present to an extent of at least 10% (by weight), in particular at least 50% (by weight).
16. Switching arrangement according to Claim 15, characterized

    in that the high-melting component essentially comprises at least one of the following materials: W, Mo, Ir.
17. Switching arrangement according to Claim 18, characterized

    in that the lower-melting component contains at least one of the following materials: Cu, Ag, Ti, Fe.
18. Switching arrangement according to one of Claims 1 to 19, characterized

    in that the base body (26, 50, 56) comprises a flexible, in particular elastically deformable material.
19. Switching arrangement according to one of Claims 1 to 18, characterized

    in that the base body (26, 28, 35, 50, 56, 60, 61) essentially comprises at least one of the following materials: Cu, Ag, Fe, steel, Al, CuBe, CuCr, CuCrZr.
20. Method for producing a switching arrangement according to one of Claims 1 to 19, characterized

    in that a base body (26, 28, 35, 50, 56, 60, 61) for at least one component of the switching arrangement is produced, at least a partial area of the surface of which base body is set back with respect to the final dimension of the surface, and a protective layer (27, 29, 36, 37, 51, 57, 58, 59) which is resistant to contact erosion is applied to the partial area by means of plasma spraying, which protective layer fills the difference with respect to the final dimension of the surface.
21. Method according to Claim 20, characterized

    in that the plasma spraying is carried out in vacuum.
22. Method according to Claim 20 or 21, characterized

    in that the protective layer (27, 29, 36, 37, 51, 57, 58, 59) is machined further after plasma spraying, in particular by milling, grinding or polishing.

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