EP0951038A1 - Arcing contact arrangement - Google Patents

Abstract

Contact fingers (4) encircle the switching axis (1). They extend from an inner edge forming the contact zone, widening outwardly, and include an angle of at least 45 degrees with the switching axis.

Description

Technical field

The invention relates to an erosion switching arrangement especially for circuit breakers like those in power plants, Substations and other facilities of the Electrical energy supply for switching on and off Operating and overcurrents are used.

State of the art

From EP-B-0 177 714 is a generic Burn-up switching arrangement is 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 prone to damage, because the contact fingers have parallel currents at a short distance lead and therefore very strong by electromagnetic forces pulled against each other. This can lead to bending and Unscrew the contact fingers. The frictional forces too between switching pin and contact fingers can be very achieve high values so that large driving forces are necessary are and strong abrasion on the switching pin and Contact fingers occur.

Presentation of the invention

The invention has for its object a Specify burn-up switching arrangement in which the Switching elements mechanically not even at high currents be overloaded and there is no excessive contact pressure.

This is achieved by the features of claim 1. By the same ensures that the current paths through the Contact elements not close to each other are guided in parallel, but quickly from the contact zone diverge and possibly larger Distance be run parallel so that none are oversized Forces act on the contact elements. The attractions on the other hand, do not need to be completely prevented, they on the contrary, by appropriate management of the Current paths are set to contribute to the necessary contact pressure between the contact elements and the Make switching pin and preferably the contact lifting forces 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 exemplary embodiments are shown, which only serve to explain the invention. Show it

Fig. 1

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

Fig. 2

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

Fig. 3

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

Fig. 4

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

Fig. 5

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

Fig. 6

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

Fig. 7

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

Fig. 8a

3 shows an axial longitudinal section through an erosion switching arrangement according to an eighth embodiment of the invention, on the left in the switch-on position, on the right shortly before reaching the switch-on position,

Fig. 8b

FIG. 8a shows an axial top view of part of the erosion switching arrangement according to FIG. 8a,

Fig. 8c

7 shows a section along CC in FIG. 8b,

Fig. 9

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

Ways of Carrying Out the Invention

1 according to a first embodiment of the invention is a Switch axis 1 is approximately rotationally symmetrical. Along the switching axis 1 is a switching pin 2 with a Tip 3 made of fire-resistant material such. B. WCu, Graphite, CFC, Graphite / Cu or CFC / Cu between the left shown switch-on position and the one shown on the right Switch-off position by means of a not shown Shift actuator slidable. A first contact piece comprises a ring of arranged around the switching axis 1, radially directed against the same contact elements as elongated contact fingers 4 are formed, which on their Wear ends of erosion heads 5 made of erosion-resistant material.

The contact fingers 4 together form an approximately circular contact part, the against the Switch axis 1 directed contact surfaces of the erosion heads 5 one in the on position on the outside of the Represent switching pin 2 adjacent contact zone. From Abbrandkopf 5 apart from each contact finger 4 is in one piece with a 90 ° turn in the switch-on direction, so with the contact finger 4 a right angle including web 6 made of highly conductive spring-elastic Material made and fixed to a housing part 7 anchored, via which the web 6 with a first electrical Connection is connected. The switching pin 2 forms against it a second contact piece, the z. B. via a flexible Line or a sliding bell with a second electrical Connection is connected.

A support body 8 is located in an opening of the housing part 7 attached from electrically insulating material, the cylindrical outer surface forms a support surface 9, on which the webs 6 rest in the off position. In the On the other hand, the contact fingers 4 by the Contact of the erosion heads 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 be quite because of the high elasticity of the webs 6 be chosen large, so that a large burn-up reserve for Available. In the middle, the support body 8 has a Opening, which is a nozzle surrounding the switching axis 1 10 forms, in which the tip 3 in the switched-on position of the switching pin 2 protrudes.

Commutates the current from one during a shutdown Not shown current switching arrangement on the Burn-up switching arrangement, the current then flows on the contact zone in the radial direction through the contact fingers 4. It is only at a greater distance R from the switching axis 1 deflected in a direction parallel to the same and flows over a distance L through the parallel webs 6.

The radially outward parts of the current paths in the contact fingers 4 practice a relatively small electromagnetic force on each other and also the Action of the through the switching pin 2 Portions of the current path on them can be neglected become. The subsequent parallel current paths through the Bars 6 attract each other, but the radial one Component of attraction because of the relatively large Distance to switching axis 1 is not so great that Damage or excessive pressure on the contact fingers 4 against the switching pin 2, the excessive abrasion of the Burning heads 5 and obstructions to the switching pin movement Could have consequences.

The distance R of the web 6 from the switching axis 1 and On the contrary, the length L of the same can be set that the mutual attraction of the contact fingers 4 in the Current levels to be expected due to the elastic deflection of the contact fingers 4 of the same contact pressure exerted against the switching pin 2 desired way reinforced and especially the between these parts effective contact lifting forces compensated. Such compensation remains above all Fluctuations in amperage received because Contact lifting and attraction forces in the same way depend on the same. With the further movement of the Switch pin 2 is the same from the wreath of Contact fingers 4 pulled and the erosion heads 5 of the same move against the switching axis 1 until the webs 6 on the Support surface 9 bear. Further radial movement of the Contact finger 4 against the switching axis 1 under the influence the mutual attraction of the current paths through the bridges 6 is prevented.

Between the erosion heads 5 and the tip 3 of the Switch pin 2 arises as soon as the latter out of the wreath the contact finger 4 is drawn, an arc 11. It will e.g. B. by means of blow pistons, not shown, wherein the gas flows out through the nozzle 10 so that it is at next current zero crossing is deleted.

The burn-up switching arrangement shown in FIG. 2 according to a second embodiment of the invention corresponds to what the first contact piece concerns completely the first Embodiment. However, the second contact piece comprises in addition to switching pin 2, an erosion contact arrangement, which in turn corresponds exactly to the first contact Contact fingers 4 'with erosion heads 5' which in the Switch on position with a second contact zone forming inner surfaces against the peripheral surface of the Press the switching pin 2, the contact fingers 4 'in turn Connect to webs 6 'angled by approx. 90 ° and over the same and a housing part 7 'with the second electrical connection are connected so that the Contact finger 4 'also functions as a sliding tulip perceive. The webs 6 'are in the off position again on a support surface 9 'from the outside a support body 8 'is formed, which is also a forms the switching axis 1 surrounding nozzle 10 '.

When switching off, commutates as soon as switching pin 2 the contact finger 4 'is drawn from the ring, the Arc 11 from its tip 3 to the erosion heads 5 ' the contact finger 4 ', so that it then between the same and the erosion heads 5 of the contact fingers 4 of the first Contact piece burns. When blowing the arc 11 the gas flows through both nozzles 10, 10 ', which is its favored rapid deletion.

The erosion switching arrangement according to that in FIG. 3 illustrated third embodiment of the invention otherwise corresponds completely to that according to the second Embodiment, but the contact fingers 4, 4 'are each Burning rings 12, 12 'prescribed. They form parts of pot-shaped shields 13, 13 'which, with the webs 6 or 6 'connected in an electrically conductive manner, in each case the rest Surround parts of the contact pieces and completely shield them. When switched off, the arc 11 commutates rapidly the erosion heads 5 of the contact fingers 4 on the erosion ring 12, while it from the tip 3 of the switching pin 2 in essentially commutates on the erosion ring 12 ', which the Burning of the contact fingers 4, 4 'is reduced and thus theirs Lifespan increased.

4 according to corresponds to a fourth embodiment of the invention in their basic structure of that after the first Embodiment, but the contact fingers 4, from which the first contact piece is made so that it aligns with the switching axis 1 seen in the switch-on direction an angle Include α of approx. 65 °. Except for the comparatively long erosion heads 5, made of resilient highly conductive material, are straight and right up to that Housing part 7 guided and anchored to the same, so that they together form an approximately funnel-shaped contact part.

Here, too, the fact that the current paths rapidly diverge from the contact zone, ie the inner sides of the erosion heads 5 touching the switching pin 2, 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 extension and the radius R _{0 of} the switching pin 2 and the length L' of the axial component of its extension so that it does not damage the contact fingers, excessive abrasion of the erosion heads 5 or obstructions leads the switching pin movement, but makes a contribution to the application of sufficient contact pressure, in particular a compensation of the contact lifting forces. In this case, the support body 8 forms a support surface 9 in the shape of a truncated cone, which lies at a distance below the contact fingers 4 and limits their mobility against the switching axis 1. The course of a switch-off corresponds to that described in connection with the erosion switching arrangement according to the first embodiment of the invention.

In a burn-up switching arrangement shown in FIG. 5 according to a fifth embodiment of the invention the basic structure corresponds to that of the Burn-up switching arrangement according to the first embodiment of the Invention. Instead of contact fingers are however as Contact elements contact pieces 4 "provided preferably exactly radially displaceable in corresponding radial recesses 14 open against the switching axis 1 a retaining ring 15 surrounding the same are stored, which is attached to the housing part 7 and the same with the first electrical connection electrically connected and which also forms the nozzle 10. The retaining ring 15 is otherwise solid and consists of electrical conductive material. On the inside and also on the inside the switch-off position against the counter-switch Switch pin 2 facing side, it is with a panel 16 made of fire-resistant material.

The contact pieces 4 "only protrude at least on their front ends of erosion-resistant tips 17 through corresponding openings in the panel 16, while the same a stop for the front shoulders of her form wider body 18. The electrical contact with the Retaining ring 15 is made by contact lamellae 19. By means of a pushing against its back Spring element, namely a spiral spring 21 which on a the outer lining 20 closing the recess 14 of the Holding rings 15 is supported, the contact piece is 4 " each with a radially acting against the switching axis 1 Force applied.

Again, the current paths from the contact zone, i.e. H. the the front ends of the tips 17 touching the switching pin 2 the contact pieces 4 "led radially outwards, so that the electromagnetic forces that they have against each other exert no significant influence on the contact pressure with which the contact pieces 4 "against the peripheral surface of switch pin 2. The required contact pressure is applied by the spiral spring 21. When switching off commutates between the tip 3 of the switching pin 2 and the arcs 11 drawn from the tips 17 of the contact pieces 4 " immediately from the latter to the fairing 16, whose end area on the switch-off side thus the function of a Contact pieces 4 "upstream erosion ring met.

6 according to corresponds to a sixth embodiment of the invention largely that described above, but are the Recesses 14 formed continuously and the body 18th of the contact pieces 4 "so long that they are slightly above the Protrude outside the retaining ring 15. As a spring element a leaf spring 22 is provided, which against the Back of the contact piece 4 "presses.

7 according to corresponds 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 slide guides 23 which in the Recesses 14 are attached. Also the electrical one Contact with the retaining ring 15 here via a flexible Band 24 made of highly conductive material, one of which End with the back of the contact piece 4 "electrical is conductively connected, in particular welded, while the other end with the retaining ring 15 is electrically conductive connected is.

According to an eighth shown in Fig. 8a-c Embodiment of the invention is the first contact piece as rigid first switching ring 25 made of erosion-resistant material trained, which is fixed in the housing and over the same also electrically conductive with the first electrical Connection is connected. The second contact piece comprises a switching pin 2, which, in a switch-off direction supported limited compressible disc spring package 26, is axially slidably attached to a bracket 27 which by a switching drive, not shown, along the Switch axis 1 can be moved, as well as a contact part, that as an annular disc 28 made of highly conductive resilient material, e.g. B. CuBe or CuCrZr is trained. It has a continuous outer ring 29 on, which is screwed to the housing part 7 and six through from the central opening to the outer ring 29 through radial slots 30 separate sectors 31 as Contact elements. Each of the sectors 31 of the circular disc 28 carries on its inner edge a made of fire-resistant Material existing sector 32 of a second switching ring 33. Via the housing part 7 is the outer ring 29 with which second electrical connection electrically connected.

The switching pin 2 has, compared to its tip by about Distance between the first switching ring 25 and the second Switch ring 33 offset in the switch-off direction, a rotating one Shoulder 34 on. The top is in the ON position of the switching pin 2, from the compressed disc spring package 26 with sufficient contact pressure at which Front of the first switching ring 25 all around, while the Shoulder 34 against a contact zone on the second switching ring 33 presses and the sectors 32 of the same under elastic Deformation of the sectors 31 of the circular disk 28 axially in Switching direction deflects slightly, so that through the elastic restoring forces of the sectors 31 also here there is sufficient contact pressure.

Because of the essentially radial direction of the partial flows through the sectors 31 on the circular 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 switching rings 25 anyway no risk of Deformation or other damage from electromagnetic forces.

When switching off between the first switching ring 25 and an arc is drawn from the tip of the switching pin 2. 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 about. The now the first switching ring 25 and the second switching ring 33 connecting arc is laterally blow the gas through the two switch rings escapes.

The burn-up switching arrangement shown schematically in FIG. 9 according to a ninth embodiment of the invention is similar to the one described above.

However, here is the first switching piece as from the inside Edge slotted first circular washer 35 highly conductive resilient material. Of the Switch pin 2 is rigid on a not shown a shift actuator displaceable along the shift axis 1 Bracket attached and a sliding tulip 36 with the second electrical connection electrically connected. The elastic restoring force of the first circular disc 35, the inner edge 37 of a fire-resistant material easy in the switch-on position axially in the switch-on direction deflected contact zone provides a sufficient Contact pressure safe. The second switching piece includes one with the second electrical connection is electrically conductive connected rigid second circular washer 38 erosion-resistant material whose inner diameter only is slightly larger than the diameter of the Switch pin 2. It acts as a burn ring, on the Switch off the one arc base point from switching pin 2 skips.

Reference list

1

Shift axis

2nd

Switching pin

3rd

Tip of the switching pin 2

4, 4 '

Contact finger

4 "

Contact pieces

5, 5 '

Burn heads

6, 6 '

Walkways

7, 7 '

Housing parts

8, 8 '

Support body

9, 9 '

Support surfaces

10, 10 '

Nozzles

11

Electric arc

12, 12 '

Burn rings

13, 13 '

Shields

14

Recesses

15

Retaining ring

16

Covering the retaining ring 15

17th

Tip of contact 4 "

18th

4 "Contact Body

19th

Contact blades

20th

Outer wall of the retaining ring 15

21

Coil springs

22

Leaf springs

23

Sliding guides

24th

tape

25th

first switching ring

26

Disc spring package

27

bracket

28

Circular washer

29

Outer ring of circular disk 28

30th

Slits in circular disk 28

31

Sectors of the circular disk 28

32

Sectors of the second switching ring 33

33

second switching ring

34

Shoulder of the switch pin 2

35

first circular disc

36

Sliding tulip

37

Inner edge of the first circular washer 35

38

second circular disc

Claims (20)

Burn-up switching arrangement with, in a housing, a first contact piece which is connected to a first electrical connection in at least one switch-on position and a second contact piece which is connected to a second electrical connection at least in the switch-on position and which comprises a switch pin (2) which by means of a switching drive along a switching axis (1) relative to the first switching element between the switch-on position, in which the first switching element touches the switching pin (2), so that the erosion switching arrangement closes a current path between the first electrical connection and the second electrical connection and a switch-off position, in which the switching pin (2) is spaced from the first switching piece, can be changed over, with at least one contact part which belongs to one of the switching pieces and which contacts the switching pin (2) with a contact zone surrounding the switching axis in the switched-on position, thereby ge indicates that the contact part surrounds the switching axis (1) like a ring and, starting from an inner edge which forms the contact zone, expands in such a way that it encloses an angle of at least 45 ° with the switching axis (1). Burn-up switching arrangement according to claim 1, characterized in that the angle between the switching axis (1) and the contact part is at least 60 °. Burn-up switching arrangement according to Claim 3, characterized in that the contact part is directed outwards at least approximately radially from the switching axis (1). Burn-up switching arrangement according to one of claims 1 to 3, characterized in that the contact zone in the switched-on position is elastically deflected under the action of the switching pin (2). Burn-up switching arrangement according to one of claims 1 to 4, characterized in that the contact part consists of a plurality of at least approximately straight contact elements directed against the switching axis (1). Burn-up switching arrangement according to claim 5, characterized in that each contact element is designed as an elongated contact finger (4, 4 '). Burn-up switching arrangement according to one of Claims 4 to 6, characterized in that the contact zone is deflected essentially radially in the switched-on position and touches the switching pin (2) on its peripheral surface. Burn-up switching arrangement according to claims 6 and 7, characterized in that each contact finger (4, 4 ') on a web (6, 6') made of flexible, in particular spring-elastic, electrically conductive material, which at least part of the electrically conductive connection between the contact finger ( 4, 4 ') and the corresponding electrical connection, angled. Burn-up switching arrangement according to Claim 8, characterized in that the web (6, 6 ') is firmly anchored at least approximately parallel to the switching axis (1) and at its end remote from the contact finger (4, 4'). Burn-up switching arrangement according to claims 6 and 7, characterized in that each contact finger (4) is at least approximately straight, consists of flexible, in particular spring-elastic material over at least part of its length and is firmly anchored at its end facing away from the switching axis (1). Burn-up switching arrangement according to claim 10, characterized in that each contact finger (4) is directed obliquely against the switching axis (1). Burn-up switching arrangement according to one of Claims 8 to 11, characterized in that the web (6) or the contact finger (4, 4 ') bears against an outwardly facing support surface (9, 9') in the switched-off position. Burn-up arrangement according to Claim 7, characterized in that the contact elements are each designed as radially displaceable contact pieces (4 ") mounted in a holder surrounding the switching pin (2) in the switched-on position. Burn-up switching arrangement according to claim 13, characterized in that the holder is designed as a retaining ring (15) surrounding the switching axis (1) with at least radial recesses (14) open towards the switching axis (1) for receiving the contact pieces (4 "). Burn-up switching arrangement according to one of Claims 4 to 6, characterized in that the contact zone is essentially axially deflected in the switch-on position and touches the switch pin (2) on an abutment surface pointing essentially against the switch-on direction. Burn-up switching arrangement according to Claim 15, characterized in that the contact elements comprise sectors (31), separated by slots (30), of an annular disc (28) made of resilient material, on the inner edge of which the contact zone is arranged. Burn-up switching arrangement according to claim 16, characterized in that the slots (30) run radially. Burn-up switching arrangement according to claim 16 or 17, characterized in that the annular disc (28) comprises a closed outer ring (29). Burn-up switching arrangement according to one of claims 15 to 18, characterized in that the abutting surface is formed by a circumferential shoulder (34) of the switching pin. Burn-up switching arrangement according to one of claims 15 to 18, characterized in that the abutting surface is formed by the tip (3) of the switching pin (2).

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