EP0951038B1 - Arcing contact arrangement - Google Patents

Description

Technical area

The invention relates to a burnup circuit arrangement especially for circuit breakers, as used in power plants, Substations and other facilities of the Electric power supply for switching on and off of Operating and overcurrents are used.

State of the art

From EP-B-0 177 714 is a generic Abbrandschaltanordnung known, in which the first Contact piece as a contact tulip with several longer, over the Scope of the same distributed parallel contact fingers is trained. It has been shown that such Arrangement at high currents is susceptible to damage, since the contact fingers at a small distance parallel currents lead and therefore very strong by electromagnetic forces be pulled against each other. This can be to bending and Turn off the contact fingers lead. Also the friction forces between the contact pin and contact fingers can be very achieve high values, so that large driving forces needed are and strong abrasion at the switching pin and the Contact fingers occurs.

Presentation of the invention

The invention is based on the object To provide burn-off switching arrangement in which the Switching pieces are not mechanically strong even at high currents overloaded and no excessive contact pressure arises.

This is achieved by the features of claim 1. By they will ensure that the current paths through the Contact elements not close to each other are guided in parallel, but from the contact zone from quickly diverge and possibly later in greater Distance parallel, so no oversized Forces act on the contact elements. The attractions on the other hand, they do not need to be completely stopped, they On the contrary, by appropriate leadership of the Rungs are set to contribute to the necessary contact pressure between the contact elements and the Make switching pin and preferably the Kontaktabhebekräfte just about compensate.

Brief description of the drawings

Fig. 1

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer ersten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 2

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer zweiten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 3

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer dritten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 4

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer vierten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 5

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer fünften Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 6

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer sechsten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 7

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer siebten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung,

Fig. 8a

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer achten Ausführungsform der Erfindung, links in der Einschaltstellung,rechts kurz vor Erreichen der Einschaltstellung,

Fig. 8b

eine axiale Draufsicht auf einen Teil der Abbrandschaltanordnung nach Fig. 8a,

Fig. 8c

einen Schnitt längs C-C in Fig. 8b,

Fig. 9

einen axialen Längsschnitt durch eine Abbrandschaltanordnung gemäss einer neunten Ausführungsform der Erfindung, links in Einschalt-, rechts in Ausschaltstellung.

In the drawings, several embodiments are shown, which serve only to illustrate the invention. Show it

Fig. 1

an axial longitudinal section through a Abbrandschaltanordnung according to a first embodiment of the invention, left in on, right in off position,

Fig. 2

an axial longitudinal section through a Abbrandschaltanordnung according to a second embodiment of the invention, left in on, right in off position,

Fig. 3

an axial longitudinal section through a Abbrandschaltanordnung according to a third embodiment of the invention, left in on, right in off position,

Fig. 4

an axial longitudinal section through a Abbrandschaltanordnung according to a fourth embodiment of the invention, left in on, right in the off position,

Fig. 5

an axial longitudinal section through a Abbrandschaltanordnung according to a fifth embodiment of the invention, left in on, right in off position,

Fig. 6

an axial longitudinal section through a Abbrandschaltanordnung according to a sixth embodiment of the invention, left in on, right in the off position,

Fig. 7

an axial longitudinal section through a Abbrandschaltanordnung according to a seventh embodiment of the invention, left in on, right in off position,

Fig. 8a

an axial longitudinal section through a Abbrandschaltanordnung according to an eighth embodiment of the invention, left in the closed position, right shortly before reaching the closed position,

Fig. 8b

8 is an axial plan view of a portion of the burn-off circuit arrangement according to FIG. 8a;

Fig. 8c

a section along CC in Fig. 8b,

Fig. 9

an axial longitudinal section through a Abbrandschaltanordnung according to a ninth embodiment of the invention, left in on, right in the off position.

Ways to carry out the invention

The Abbrandschaltanordnung shown in Fig. 1 according to A first embodiment of the invention is a Switching axis 1 formed approximately rotationally symmetrical. Along the switching axis 1 is a switching pin 2 with a Tip 3 made of burn-resistant material such. B. WCu, Graphite, CFC, graphite / Cu or CFC / Cu between the left shown switch-on position and shown on the right Off position by means of a not shown Shift drive displaceable. A first contact piece comprises a wreath arranged around the switching axis 1, radially against the same directed contact elements, which as elongated contact fingers 4 are formed, which at their Ends wear burners 5 made of burn-resistant material.

The contact fingers 4 together form an approximately annular contact part, wherein the against the Switching axis 1 directed contact surfaces of Abbrandköpfe. 5 one in the closed position on the outside of the Switch pin 2 present adjacent contact zone. from Abbrandkopf 5 apart, each contact finger 4 is in one piece with a bent by about 90 ° in the switch-on, so with the contact finger 4 a right angle including web 6 of hochleitendem spring elastic Material produced and fixed to a housing part 7 anchored over which the bridge 6 with a first electric Connection is connected. The switching pin 2 forms against it a second contact piece, the z. B. via a flexible Cable or a sliding tulip with a second electrical Connection is connected.

In an opening of the housing part 7 is a support body. 8 fastened from electrically insulating material whose cylinder jacket-shaped outer side forms a support surface 9, at the webs 6 rest in the off position. In the Switching position, however, are the contact fingers 4 through the Contact the Abbrandköpfe 5 with the peripheral surface of the Switch pin 2 deflected radially outwards under elastic deformation of the webs 6, which of the Support surface 9 are lifted. The initial deflection can because of the high elasticity of the webs 6 pretty much be chosen large, so that a large burn-up reserve for Available. In the middle, the support body 8 has a Open on which a surrounding the switching axis 1 nozzle 10 forms, in which in the closed position, the top of the third of the switching pin 2 protrudes.

Commutes in the course of an elimination of the current of one not shown rated current switching arrangement on the Abbrandschaltanordnung, so the current flows in the connection the contact zone in the radial direction through the contact fingers 4. Only at a greater distance R from the switching axis 1 he becomes deflected in one to the same parallel direction and flows through a distance L through the parallel webs. 6

The radially outwardly directed parts of the current paths in The contact fingers 4 practice a relatively low electromagnetic force on each other and also the Action of passing through the switching pin 2 Section of the rung to the same can be neglected become. The subsequent parallel current paths through the Webs 6 attract each other, but is the radial Component of attraction because of the relatively large Distance to the switching axis 1 is not so great that Damage or excessive pressure of the contact fingers 4 against the switching pin 2, the excessive abrasion of the Abbrandköpfe 5 and obstructions of the switching pin movement to Could have a consequence, to be feared.

The distance R of the web 6 from the switching axis 1 and the Length L of the same can be set on the contrary so that the mutual attraction of the contact fingers 4 in the typically expected currents due to the elastic deflection of the contact fingers 4 of the same against the switching pin 2 exerted contact pressure desired way amplified and in particular the between these parts have effective contact lift forces approximately compensated. Such compensation remains above all Fluctuations in the current received, since Contact lift forces and attractions in the same way depend on the same. In the further movement of the Schaltstiftes 2 will be the same from the wreath of Contact fingers 4 pulled and the burn-off heads 5 of the same move against the switching axis 1 until the webs 6 at the Support surface 9 abut. Further radial movement of Contact finger 4 against the switching axis 1 under the influence the mutual attraction of the current paths through the bridges 6 is thus prevented.

Between the Abbrandköpfen 5 and the top 3 of the Switch pin 2 is formed as soon as the latter from the wreath the contact finger 4 is pulled, an arc 11. He will z. B. blown by means not shown blow piston, wherein the gas flows through the nozzle 10, so that he next zero crossing is cleared.

The Abbrandschaltanordnung shown in FIG A second embodiment of the invention corresponds to what the first contact piece, completely the first Embodiment. However, the second contact piece comprises in addition to the switching pin 2, a consumable contact arrangement, which in turn corresponds exactly to the first contact piece with Contact fingers 4 'with Abbrandköpfen 5', in the Closed position with its a second contact zone forming inner surfaces against the peripheral surface of the Press switch pin 2, wherein the contact fingers 4 'turn at webs 6 'angled about 90 ° and connect the same and a housing part 7 'with the second electrical connection are connected, so that the Contact finger 4 'at the same time the function of a sliding tulip perceive. The webs 6 'are in the off position in turn on a support surface 9 ', which from the outside a support body 8 'is formed, which at the same time a the switching axis 1 surrounding nozzle 10 'forms.

When switching off commuted as soon as the switch pin 2 is pulled out of the ring of contact fingers 4 ', the Arc 11 from its tip 3 on the Abbrandköpfe 5 ' the contact finger 4 ', so that he then between the same and the erosion heads 5 of the contact fingers 4 of the first Contact piece burns. At the blowing of the arc 11 the gas flows through both nozzles 10, 10 ', which is his rapid deletion favored.

The consumable switching arrangement according to the in Fig. 3rd illustrated third embodiment of the invention otherwise corresponds otherwise completely to that according to the second Embodiment, but are the contact fingers 4, 4 'respectively Abbrandringe 12, 12 'assigned. They form parts of cup-shaped shields 13, 13 ', which, with the webs. 6 or 6 'electrically connected, in each case the others Surround parts of the contact pieces and completely shield. When switched off, the arc 11 commutates rapidly from the erosion heads 5 of the contact fingers 4 on the Abbrandring 12, while from the top 3 of the switch pin 2 in essentially on the Abbrandring 12 'commutated, which the Burning of the contact fingers 4, 4 'is reduced and thus their Lifespan increased.

The Abbrandschaltanordnung shown in Fig. 4 according A fourth embodiment of the invention corresponds to FIG their basic structure of those after the first one Embodiment, but are the contact fingers 4, from which the first contact piece is aligned so that it with the switching axis 1 viewed in the switching direction an angle Include α of about 65 °. They exist, with the exception of relatively long Abbrandköpfe 5, made of elastic highly conductive material, are straight and right up to the Housing part 7 out and anchored to the same, so that they together form an approximately funnel-shaped contact part.

Here too, the fact that the current paths from the contact zone, ie the inner sides of the burn-off heads 5 which touch the contact pin 2 are rapidly diverging, reduces the mutual attraction of the contact fingers 4. It can in turn be adjusted over the length R 'of the radial component of its extent and the radius R _{0 of} the switch pin 2 and the length L' of the axial component of their extent so that they do not damage the contact fingers, excessive wear of Abbrandköpfe 5 or disabilities the switching pin movement leads, but makes a contribution to the application of a sufficient contact pressure, in particular a compensation of Kontaktabhebekräfte. The support body 8 forms in this case a truncated cone-shaped support surface 9, which lies at a distance below the contact fingers 4 and limits their mobility against the switching axis 1. The course of an elimination corresponds to that described in connection with the Abbrandschaltanordnung according to the first embodiment of the invention.

In a burnup circuit arrangement shown in FIG according to a fifth embodiment of the invention The basic structure again corresponds to that of the Abbrandschaltanordnung according to the first embodiment of the Invention. Instead of contact fingers are however as Contact elements contact pieces 4 "provided, the preferably exactly radially displaceable in corresponding radial, open against the switching axis 1 recesses 14th a same surrounding retaining ring 15 are stored, which is attached to the housing part 7 and above the same with the electrically connected first electrical connection is and which also forms the nozzle 10. The retaining ring 15 is otherwise solid and made of electrical conductive material. On the inside and also on the in the switch off position against the counter piece, the Shift pin 2 directed side he is with a fairing 16 made of burn-resistant material.

The contact pieces 4 "project only with at least theirs front ends burn-resistant tips 17 by corresponding openings in the panel 16 while same one stop for front shoulders of her make wider body 18. The electrical contact with the Retaining ring 15 is made by contact blades 19. By means of a pressing against his back Spring element, namely a coil spring 21, which on a the recess 14 final outer panel 20 of the Retainers 15 is supported, the contact piece 4 " each with a radially acting against the switching axis 1 Force applied.

Again, the current paths are from the contact zone, d. H. the the switching pin 2 touching the front ends of the tips 17th the contact pieces 4 "out radially outwards, so that the electromagnetic forces that they make against each other exercise, no significant influence on the contact pressure have, with the contact pieces 4 "against the peripheral surface of the switch pin 2. The required contact pressure is applied by the coil spring 21. When switching off commutes between the top 3 of the shift pin 2 and the tips 17 of the contacts 4 "drawn arc 11th immediately from the latter on the panel 16, whose ausschaltseitiger end so the function of the Contact pieces 4 "upstream Abbrandrings met.

The Abbrandschaltanordnung shown in Fig. 6 according to a sixth embodiment of the invention are largely as described above, but are the Recesses 14 formed continuously and the body 18th the contact pieces 4 "so long that they something about the Outside of the retaining ring 15 protrude. As a spring element is in each case a leaf spring 22 is provided, which against the Rear of the contact piece 4 "presses.

The Abbrandschaltanordnung shown in Fig. 7 according to a seventh embodiment of the invention again the one described above, but are the Contact pieces 4 "of constant diameter and each guided in sliding guides 23, which in the Recesses 14 are attached. Also, the electric Contact with the retaining ring 15 here in each case via a flexible Band 24 made of highly conductive material, one of which End with the back of the contact piece 4 "electric conductively connected, in particular welded, while the other end with the retaining ring 15 electrically conductive connected is.

According to one shown in Fig. 8a-c eighth Embodiment of the invention is the first contact piece as rigid first switching ring 25 made of burn-resistant material formed, which is fixed in the housing and the same also electrically conductive with the first electrical Connection is connected. The second contact piece comprises a switching pin 2, the, via a in Ausschaltetrichtung limited compressible cup spring package 26 supported, axially slidably mounted on a holder 27 which by a not shown switching drive along the Switching axis 1 can be moved, and a contact part, as a circular disk 28 of highly conductive elastic material, z. B. CuBe or CuCrZr is trained. It has a continuous outer ring 29 on, which is bolted to the housing part 7 and six through from the central opening to the outer ring 29 continuous radial slots 30 separate sectors 31 as Contact elements. Each of the sectors 31 of the circular disk 28 carries on its inner edge of a burn-resistant Material existing sector 32 of a second switching ring 33. About the housing part 7 of the outer ring 29, with the second electrical connection electrically conductively connected.

The switching pin 2 has, compared to its tip to about the Distance between the first switching ring 25 and the second Switching ring 33 offset in Ausschichttrichtung, a circumferential Shoulder 34 on. In the closed position is the top of the switching pin 2, from the compressed cup spring package 26th with a sufficient contact pressure applied to the Front of the first switching ring 25 all around, while the Shoulder 34 against a contact zone on the second switching ring 33rd presses and the sectors 32 of the same under elastic Deformation of the sectors 31 of the annular disc 28 axially in Switching direction slightly deflects, so that through the elastic restoring forces of the sectors 31 also here sufficient contact pressure is given.

Because of the substantially radial direction of the partial streams through the sectors 31 occur on the annular disk 28th no electromagnetic forces that are essential could affect the contact pressure. In the area of first contact piece exists because of the rigid design of the first Schaltrings 25 anyway no danger of Deformations or other damage by electromagnetic forces.

When you turn off between the first switching ring 25 and the tip of the switching pin 2 pulled an arc. As soon as the tip of the switching pin 2 the second switching ring 33 happens, the arc base jumps from the former on the latter over. The now the first switching ring 25 and the second switching ring 33 connecting arc becomes laterally Blow over, taking the gas through the two switching rings escapes.

The burnup circuit arrangement shown schematically in FIG. 9 according to a ninth embodiment of the invention is formed similar to the above-described.

However, here is the first contact piece as the inner Rand ago slotted first annular disc 35 highly conductive resilient material formed. Of the Switch pin 2 is rigidly on a not shown by a shift drive along the shift axis 1 slidably Attached bracket and a sliding tulip 36 with the second electrical connection electrically conductively connected. The elastic restoring force of the first annular disc 35, the inner edge 37 of burn-resistant material a in the switch-on axially in the switch-on easily forms a deflected contact zone, provides a sufficient Contact pressure safe. The second contact piece comprises a the second electrical connection electrically conductive connected rigid second annular disc 38 burn-resistant material whose internal diameter only is slightly larger than the diameter of the Schaltstiftes 2. It acts as Abbrandring, on the Turn off the one arc base point of the switch pin 2 skips.

LIST OF REFERENCE NUMBERS

1

switching axis

2

switch Probe

3

Tip of the switching pin 2

4, 4 '

contact fingers

4 '

contacts

5, 5 '

Abbrandköpfe

6, 6 '

Stege

7, 7 '

housing parts

8, 8 '

support body

9, 9 '

support surfaces

10, 10 '

jet

11

Electric arc

12, 12 '

Abbrandringe

13, 13 '

shields

14

recesses

15

retaining ring

16

Fairing of the retaining ring 15

17

Tip of the contact piece 4 "

18

Body of contact piece 4 "

19

Multilams

20

Outer wall of the retaining ring 15

21

coil springs

22

leaf springs

23

sliding guides

24

tape

25

first switching ring

26

Belleville spring assembly

27

bracket

28

Annular disk

29

Outer ring of the annular disc 28

30

Slits in annular disk 28

31

Sector of the annular disc 28

32

Sectors of the second switching ring 33

33

second switching ring

34

Shoulder of the switching pin 2

35

first circular disk

36

sliding tulip

37

Inner edge of the first annular disc 35th

38

second circular disk

Claims (20)

1. Consumable switching arrangement having, in a housing, a first contact member, which is connected at least in one closed position to a first electric terminal, and a second contact member, which is connected at least in the closed position to a second electric terminal and which comprises a contact pin (2) which can be changed over relative to the first contact member along a switching axis (1) by means of a switching drive between the closed position, in which the first contact member touches the contact pin (2) so that the consumable switching arrangement closes a current path between the first electric terminal and the second electric terminal, and an open position, in which the contact pin (2) is spaced apart from the first contact member, and having at least one contact part which belongs to one of the contact members and which touches the contact pin (2) in the closed position with a contact zone surrounding the switching axis, characterized in that the contact part surrounds the switching axis (1) like a wreath and, starting from an inner edge which forms the contact zone, widens in such a way that it encloses an angle of at least 45° with the switching axis (1)
2. Consumable switching arrangement according to Claim 1, characterized in that the angle between the switching axis (1) and the contact part is at least 60°.
3. Consumable switching arrangement according to Claim 2, characterized in that the contact part is directed outwards from the switching axis (1) at least approximately radially.
4. Consumable switching arrangement according to one of Claims 1 to 3, characterized in that, in the closed position, the contact zone is elastically deflected under the action of the contact pin (2).
5. Consumable switching arrangement according to one of Claims 1 to 4, characterized in that the contact part comprises a plurality of contact elements directed at least approximately rectilinearly towards the switching axis (1).
6. Consumable switching arrangement according to Claim 5, characterized in that each contact element is constructed as an elongated contact finger (4, 4').
7. Consumable switching arrangement according to one of Claims 4 to 6, characterized in that, in the closed position, the contact zone is deflected essentially radially and touches the contact pin (2) on its circumferential surface.
8. Consumable switching arrangement according to Claims 6 and 7, characterized in that each contact finger (4, 4') adjoins at an angle a web (6, 6') which is made from a flexible, in particular springy electrically conducting material, which forms at least a part of the electrically conducting connection between the contact finger (4, 4') and the corresponding electric terminal.
9. Consumable switching arrangement according to Claim 8, characterized in that the web (6, 6') is permanently anchored in each case at least approximately parallel to the switching axis (1) and at its end averted from the contact finger (4, 4').
10. Consumable switching arrangement according to Claims 6 and 7, characterized in that each contact finger (4) is at least approximately straight, consists at least over a part of its length of a flexible, in particular springy material, and is permanently anchored at its end averted from the switching axis (1).
11. Consumable switching arrangement according to Claim 10, characterized in that each contact finger (4) is directed obliquely towards the switching axis (1).
12. Consumable switching arrangement according to one of Claims 8 to 11, characterized in that, in the open position, the web (6) and/or the contact finger (4, 4') bears against an outwardly pointing supporting surface (9, 9').
13. Consumable switching arrangement according to Claim 7, characterized in that the contact elements are constructed as contact pieces (4") mounted in a radially displaceable fashion in a holder surrounding the contact pin (2) in the closed position.
14. Consumable switching arrangement according to Claim 13, characterized in that the holder is constructed as a holding ring (15) surrounding the switching axis (1) and has, for the purpose of holding the contact pieces (4"), radial cutouts (14) which are open at least towards the switching axis (1).
15. Consumable switching arrangement according to one of Claims 4 to 6, characterized in that, in the closed position, the contact zone is deflected essentially axially and touches the contact pin (2) at an impact surface pointing essentially in the closing direction.
16. Consumable switching arrangement according to Claim 15, characterized in that the contact elements comprise sectors (31), separated by slits (30), of a circular disc (28) made from springy material, at whose inner edge the contact zone is arranged.
17. Consumable switching arrangement according to Claim 16, characterized in that the slits (30) run radially.
18. Consumable switching arrangement according to Claim 16 or 17, characterized in that the circular disc (28) comprises a closed outer ring (29).
19. Consumable switching arrangement according to one of Claims 15 to 18, characterized in that the impact surface is formed by a circumferential shoulder (34) of the contact pin.
20. Consumable switching arrangement according to one of Claims 15 to 18, characterized in that the impact surface is formed by the tip (3) of the contact pin (2).

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