RU2830668C2 - Switching device for conducting high continuous currents and very high short-circuit currents - Google Patents

Abstract

FIELD: electrical communication equipment.

SUBSTANCE: invention relates to switching device (1) for conducting high continuous currents and very high short-circuit currents. Switching device (1) comprises at least two contact points (9, 10), wherein each contact point comprises movable contact (11) and fixed contact (12), wherein one of contacts (12) of each contact point (9, 10) is formed in socket (13), and other contact (11) of each contact point (9, 10) is formed on pin (14), which is configured to be placed in socket (13), seat (13), and movable contacts (11) of both contact points (9, 10) are made in the form of a common component; one of contacts (12) in at least one of contact points (9, 10) has ribs (26) so that in said contact point (9, 10) a plurality of contact points is defined, ribs are made as a separate component in the form of contact plates, wherein said component is located on the corresponding contact of each contact point, and the contact plates are made in the form of high-current contact strip (27), which contains elastic bearing strip (30), having two boundary edges (28) and containing a plurality of contact bridges (29), which extend across boundary edges (28) and are connected to boundary edges (28); contact parts (31) are riveted on contact bridges (29).

EFFECT: prevention of contacts welding.

12 cl, 5 dwg

Description

The present invention relates to a switching device for conducting high continuous currents and very high short-circuit currents.

A contact device for high continuous current loads is already known from DE 66 08 223 U, wherein continuous currents amount to 2000 A and more. The contact device comprises a fixed contact part and a cylindrical switching pin. The fixed contact part is arranged on the contact housing so as to be movable and is connected to an element which, when current passes through the contact device, heats up and expands or contracts, and thereby either moves, rotates or tilts the fixed contact part from its initial position. During such movement of the fixed contact part, sliding occurs between the contact surfaces in contact, which destroys the oxide shell, which prevents the current from passing and reduces the contact resistance.

US 4,039,786 shows an ultra-fast operating switch with a pin or rod-shaped movable contact lever. The contact lever is guided with the possibility of movement in a tubular guide. The contact lever can be moved by means of a drive rod connected to the relay and can be brought into interaction with a fixed contact. The fixed contact is in the form of a sleeve and has a plurality of parallel flexible fingers located at its end facing the contact lever, in which the rounded end of the contact lever can be accommodated. The tubular guide is connected to an external connecting cable by means of a metal plate, wherein the fixed contact is connected to an external clamp.

DE 718 554 A discloses a gas-insulated switchgear or an electrical switch with arc quenching by a flowing medium under pressure. The switch comprises a moving contact in the form of a pin, which can be brought into interaction with a fixed contact. In addition, the moving contact is directed into an intermediate contact and is connected to a collective contact. In the closed position of the switch, the moving contact passes through the intermediate contact and is accommodated in the fixed contact. When the switch is open, the moving contact is pulled in and directed only into the collective contact.

EP 2 525 455 A1 describes a gas-insulated switchgear with a disconnector integrated in the busbar. The disconnector integrated in the busbar comprises a pin-shaped moving contact which is directed into a moving lateral contact section. The moving contact can be moved by means of a lever element and brought into interaction with a fixed lateral contact section. This represents an electrically connected or closed state. The moving contact can be pulled out of the fixed lateral contact section again in such a way that the disconnector is in an electrically disconnected state.

US 2016/0035501 A1 also discloses a gas-insulated power switching device comprising a fixed electrode and a movable electrode located opposite each other in a container filled with an insulating gas; and a rod-shaped movable conductor electrically connecting the fixed electrode and the movable electrode. The fixed electrode and the movable electrode have a contactor through which current flows to the movable conductor. The fixed electrode and the movable electrode have annular sliding elements, wherein the annular sliding elements are located on both sides of the contactor.

It is known that switching devices may have insufficient short-circuit strength. After a short circuit, such devices are often destroyed and therefore unusable and must be replaced.

The object of the present invention is therefore to provide a switching device which avoids the problems known from the prior art and which, in particular in the unseparated state, i.e. in the contact state, can conduct high continuous currents and even higher short-term currents without welding.

The problem is solved by means of the features of independent claim 1, according to which a switching device for conducting high continuous currents and very high short-circuit currents has a solution to the said problem in accordance with the present invention, if the switching device comprises at least two contact points, wherein each contact point comprises a movable contact and a fixed contact, wherein one of the contacts of each contact point is formed in a socket, and the other contact of each contact point is formed on a pin, which is designed with the possibility of being placed in the said socket, and the movable contacts of both contact points are made in the form of a common component, wherein one of both contacts in at least one of the contact points has ribs in such a way that a plurality of contact points are defined at the said contact point, the ribs are made as a separate component in the form of contact plates, which is located on the corresponding contact of each contact point, and the contact plates are made in the form of a high-current contact strip, which contains an elastic support strip, having two boundary edges and a plurality of contact bridges, passing across the boundary edges and connected to boundary edges, while the contact parts are riveted onto the contact bridges.

This solution according to the present invention provides the switching device with the possibility of conducting high continuous currents and even higher short-term currents in the contact state without welding the contacts at the contact points. At the same time, only small forces are required for actuation.

In this case, high continuous currents are understood to mean operating currents of up to 1000 A. High or even higher short-term currents are in the range of up to 30 kA. Due to the fact that the contact points are designed as plug-in contacts, whereby each contact point comprises a socket and a pin that can be placed in the socket, and thus contact is ensured over the entire circumference of the pin and the socket that accommodates the pin, it can be ensured that electromagnetic repelling forces that occur at high currents, for example at short-circuit currents, do not lead to the opening of the contacts. Also, jitter effects that can lead to welding of the contacts are avoided. The durability of the switching device during a short circuit is increased, and the conduction of high continuous currents is ensured. By having one of the two contacts at least at one of the contact points have ribs, the transition resistance is reduced and welding of the contact points is avoided, and the possibility of safe conduction of high continuous currents of up to 1000 A and short-circuit currents of up to 30 kA is ensured. In a simple configuration, this can be achieved by implementing the ribs as a separate component in the form of contact plates, which are arranged in the corresponding contact of each contact point. The contact plates are preferably designed as a ring-shaped strip or sleeve, i.e. as a high-current contact strip, which can either be simply inserted into the pin or inserted into the socket. This thus ensures a simple design, with the spring force being geometrically located in the ring-shaped arranged contact plates.

Preferably, the sockets and the at least one pin are aligned coaxially with each other. In a simple configuration, the sockets and the at least one pin have a cylindrical shape. This allows for the contacts to be easily inserted into each other. However, other cross-sectional shapes of the socket and the pin are of course possible, provided that the contact points can be simply inserted into each other and disconnected, thus being closed and opened.

Preferred embodiments of the present invention are the subject of the additional claims.

In a preferred embodiment of the present invention, it can be provided that the fixed contact of each of said at least two contact points is formed in one socket each, and the movable contacts of said at least two contact points are formed on a common pin. Thus, during switching, the common pin is moved into the sockets or out of the sockets. This ensures a simple and stable configuration.

In particular, at least one third contact point can then be provided, which comprises a fixed contact formed in the form of a socket and a movable contact, wherein the movable contact of the third contact point is also formed on a common pin. This ensures a simple connection of at least three circuits.

According to another particularly preferred embodiment of the present invention, it can be provided that the pin is accommodated in at least one of the sockets in each switching position. In the open position, the pin is then accommodated in at least one socket, in the closed position in at least two sockets. In this way, increased stability is achieved.

According to another particularly preferred embodiment of the present invention, it can be provided that the support strip is made of spring steel and the contact parts are made of copper. The support strip made of spring steel, preferably stainless spring steel, has a high mechanical strength and excellent relaxation resistance and thus ensures mechanical strength and contact force. The contact parts made of highly conductive copper ensure a high current-carrying capacity.

According to another embodiment, it can be provided that one of the two contacts comprises two sets of ribs arranged next to each other at least in one of the contact locations in the longitudinal direction of the sockets and the pin. This parallel connection, so that the arrangement of several rib regions next to each other can further increase the current-carrying capacity of the switching device.

In order to increase the stability of the switching device, it may be provided that the pin has a central hole extending in the longitudinal direction of the pin, which is in interaction with the centering bolt.

Further increase in the stability of the switching device can be achieved by placing each of the sockets in a single block.

According to another embodiment, it can be provided that each of the integral blocks has an electrically conductive connection to the connecting terminal. In this way, a simple connection is possible.

In order to ensure safe and stable direction of said at least one movable pin, it can be provided that the pin is designed with the possibility of movement by means of at least one cylinder, preferably by means of two cylinders.

In order to cover a wide range of applications, it can be envisaged that the switching device is designed as a normally open contact or as a normally closed contact, or as a changeover contact. This is made possible by the different variants of the switching axis.

According to a further particularly preferred embodiment of the present invention, it is provided that the switching device is designed as a manual disconnector. Preferably, the switching device is designed as a manual disconnector for safe galvanic separation of the battery/voltage source and the load in the event of maintenance on battery-powered trains. In the operating state, thus in the closed state, the manual disconnector can conduct all currents that occur, thus operating currents of up to 1000 A and short-term currents of 30 kA.

An embodiment of the present invention is explained in more detail below with reference to the drawings, in which:

Fig. 1 shows an exploded view of a switching device in accordance with the present invention;

Fig. 2 shows a perspective view of the switching device in accordance with the present invention of Fig. 1 in the contact state;

Fig. 3 shows a perspective view of the switching device according to the present invention of Fig. 1 in a disconnected state;

Fig. 4 shows an exploded view of a fixed contact of the switching device according to the present invention of Fig. 1; and

Fig. 5 shows an exploded view of the movable contact of the switching device according to the present invention of Fig. 1.

In the following explanations, identical parts are designated by identical reference signs. If a figure contains reference signs that are not described in more detail in the corresponding description of the figure, reference is made to the preceding or following description of the figures.

Fig. 1 shows an exploded view of a switching device 1 according to the present invention. The switching device 1 comprises a housing 2 with two side walls 3, 4, two end walls 5, 6, a support plate 7 and a cover 8. In the housing 2, two contact places 9, 10 are formed. Each of the two contact places 9, 10 comprises a movable contact 11 and a fixed contact 12. In the embodiment shown in Fig. 1, each of the two fixed contacts 12 is formed in the form of a socket 13 or in it. The sockets 13 are made cylindrical. Each of the sockets 13 is placed in a solid block 15. Each of the blocks 15 has an electrically conductive connection with a connecting terminal 16. In the rear side wall 3 according to Fig. 1, a groove 17 is formed through which one of the connecting terminals 16 is directed outward. Similarly, in the cover 8 an additional groove 18 is formed, through which the second of the connecting terminals 16 is directed outward.

The movable contacts 12 are formed on the pin 14, which can be placed in the sockets 13. The pin 14 is also cylindrical and is designed in such a way that it can be inserted into the sockets 13 and removed from them. Thus, the sockets 13 and the pin 14 are arranged coaxially with each other. In order to ensure the possibility of moving the pin 14 relative to the sockets 13 - and, thus, opening and closing the contact places 9, 10 - the pin 14 is guided with the possibility of movement by means of two cylinders 19, which are mounted with the possibility of sliding on one of the end walls 5 of the switching device 1. The two cylinders 19 are connected to the switching mechanism 21. The cylinders 19 move with the help of this switching mechanism 21 and transmit the switching movement to the movable pin 14 with the movable contacts 11 formed on it.

On the other end surface 6 of the switching device 1, a centering bolt 20 is attached. The centering bolt 20 is also coaxial with the sockets 13 and the pin 14. The pin 14 has a central longitudinal hole in which the centering bolt 20 is placed, and thus contributes to the safe guidance of the pin 14.

Fig. 2 shows a top view of the switching device 1 in the contact state in perspective. The switching mechanism 21 is in the retracted position. This means that the cylinders 19 are maximally retracted into the housing 2 of the switching device 1 and have brought the movable pin 14 or the two movable contacts 11 formed thereon into interaction with both seats 13, which form the fixed contacts 12. In this way, the movable pin 14 is in interaction with both seats 13, both contact places 9, 10 are closed, and the switching device 1 is in the operating state. Due to the configuration of the contact places 9, 10, which is further described below, all currents that arise, i.e. operating currents of up to 1000 A and short-term currents of up to 30 kA, can be conducted.

Fig. 3 shows a top view of the switching device 1 in a disconnected state in perspective. In the disconnected state, the switching mechanism 21 is in the maximally extended position. This means that the cylinders 19 are maximally extended from the housing 2 of the switching device 1. In this way, the movable pin 14 is pulled out of one of the sockets 13 shown on the left in Fig. 3. In this way, the contact point 10 is open. At the other contact point 9, the movable pin 14 is still in interaction with the socket 13. In Fig. 3, the centering pin 20 is also shown, towards which the movable pin 14 is directed.

Fig. 4 shows an exploded view of a part of the switching device 1 according to Fig. 1, namely the configuration or arrangement of the fixed contacts 12 in the switching device 1. The arrangement of the fixed contacts 12 in both contact locations 9, 10 is identical, but rotated by 90° relative to each other in the switching device 1. The fastening of each of the fixed contacts 12 comprises a solid block 15, in which a central opening 22 is formed. In the central opening 22, in each case, one of the sockets 13 is placed. The sockets 13 are held in the solid blocks 15 via connecting terminals 16 and a retaining plate 23. The connection between the solid block 15, the retaining plate 23 and the connecting terminals 16 is preferably made by means of fastening means, such as screws 24, shown in Fig. 4.

Each of the sockets 13 has ribs 26 on its inner side 25, thus on the side that comes into contact with the movable pin 14, and on which the corresponding fixed contact 12 is formed. Thanks to the ribs, a plurality of specific contact points are formed in each of the contact places 9, 10. In this way, the current to be transmitted is distributed over a plurality of contact points so that at a contact point only a portion of the total current is to be transmitted to the counter contact. In this way, the contact resistance is reduced.

In the case shown in Fig. 4, a high-current contact strip 27 in the form of a sleeve, which forms ribs 26, is arranged in the socket 13. The high-current contact strip 27 comprises an elastic supporting strip 30 with two boundary edges 28 and a plurality of contact bridges 29, which extend perpendicularly to the boundary edges 28. A contact part 31 is riveted onto each of the contact bridges 29. The supporting strip 30 is preferably made of spring steel, in particular of stainless spring steel, wherein the contact parts 31 are made of copper. The contact parts 31, made of copper, have a high heat-absorbing capacity, which makes it possible to achieve a very high short-circuit current carrying capacity. The spring force required at the contact points is geometrically retained in the annular high-current contact strip, thus arranged with a uniform radial distribution.

It is also possible to make the ribs in the form of contact plates. Furthermore, it is also possible to form the ribs on the movable contacts, thus on the movable pin. In this case, bushings made of a high-current contact strip can be applied to the pin, as described above, in which contact bridges and thus also contact parts are formed on the outside of the bushing. In addition, it is also possible to form two or more sets of ribs arranged parallel to each other in the direction of the longitudinal axis of the pin or sockets at each contact location. This can be achieved by arranging two or more high-current contact strips in the form of a bushing next to each other parallel in the direction of the longitudinal axis L of the pin or sockets.

Fig. 5 shows an exploded view of an additional part of the switching device 1 according to Fig. 1, namely the movable pin 14 with the cylinders 19 connected to it. The cylinders 19 are connected to the movable pin 14 by means of a retaining plate 32. The connection between the cylinders 19, the retaining plate 32 and the movable pin 14 is preferably also made by means of screw connections. The movable pin 14 has a central opening 33, which extends in the longitudinal direction L of the pin 14 and, therefore, also in the longitudinal direction L of the sockets 13. The centering pin 20 (see Fig. 3) can be placed in the central opening 33. The movable contacts 11 are formed on the pin 14.

Preferably, the switching device 1 is designed as a manual disconnector for safe galvanic separation of the battery/voltage source and the load in the event of maintenance on battery-powered trains, which can conduct all currents that occur, i.e. operating currents up to 1000 A and short-term currents of 30 kA, in the operating state when the disconnector is closed.

Depending on the configuration of the switching axis, the switching device can also be designed as a normally open contact or a changeover contact. It is therefore also possible for the switching device to have three or more contact points. In this case, it is possible to connect several switching circuits. Then, preferably, several sockets are arranged one after the other in the housing of the switching device. The sockets are aligned coaxially with each other and form fixed contacts. All moving contacts are formed on a common moving pin. The moving pin is also aligned coaxially with the sockets and can connect several sockets or all the sockets.

Preferably, the switching device does not require any switching capacity and is used for no-load switching.

List of reference designations

1 switching device

2nd building

3 side wall

4 side wall

5 end wall

6 end wall

7 support plate

8 cover

9th place of contact

10th place of contact

11 movable contact

12 fixed contact

13 nest

14 pin

15 solid block

16 connecting terminal

17 groove

18 groove

19 cylinder

20 centering bolt

21 switching mechanism

22 center hole

23 retaining plate

24 screw

25 inner side of the nest

26 ribs

27 high current contact strip

28 boundary edges

29 pin jumpers

30 bearing strip

31 contact details

32 retaining plate

33 hole

L longitudinal direction

Claims (15)

1. A switching device (1) for conducting high continuous currents and very high short-circuit currents, having at least two contact points (9, 10), wherein each contact point comprises a movable contact (11) and a fixed contact (12), wherein one of the contacts (12) of each contact point (9, 10) is formed in a socket (13), and the other contact (11) of each contact point (9, 10) is formed on a pin (14), which is designed with the possibility of being placed in a socket (13), and the movable contacts (11) of both contact points (9, 10) are made in the form of a common component; wherein one of the contacts (12) at least in one of the contact locations (9, 10) has ribs (26) in such a way that in the said contact location (9, 10) a plurality of contact points are defined, the ribs are made as a separate component in the form of contact plates, wherein the said component is located on the corresponding contact of each contact location, and the contact plates are made in the form of a high-current contact strip (27), which contains an elastic support strip (30) having two boundary edges (28) and containing a plurality of contact jumpers (29) that extend across the boundary edges (28) and are connected to the boundary edges (28), in this case, the contact parts (31) are riveted onto the contact jumpers (29). 2. The switching device (1) according to claim 1, characterized in that the fixed contact (12) of each of the said at least two contact locations (9, 10) is formed in the corresponding socket (13), and the movable contacts (11) of the said at least two contact locations (9, 10) are formed on a common pin (14). 3. A switching device according to claim 2, characterized in that at least one third contact point is provided, containing a fixed contact made in the form of a socket, and a movable contact, wherein the movable contact of the third contact point is also formed on a common pin. 4. A switching device (1) according to one of the preceding claims, characterized in that the pin (14) is placed in at least one of the sockets (13) in each switching position. 5. The switching device (1) according to claim 1, characterized in that the supporting strip (30) is made of spring steel, and the contact parts (31) are made of copper. 6. A switching device (1) according to one of paragraphs 1-5, characterized in that one of the two contacts has two ribs located next to each other in at least one of the contact points in the longitudinal direction of the sockets and the pin. 7. A switching device (1) according to one of the preceding paragraphs, characterized in that the pin (14) has a central hole (33) which extends in the longitudinal direction of the pin (14) and is in interaction with the centering bolt (20). 8. A switching device (1) according to one of paragraphs 2-7, characterized in that each of the sockets (13) is located in a solid block (15). 9. The switching device (1) according to item 8, characterized in that each of the integral blocks (15) has an electrically conductive connection to the connecting terminal (16). 10. A switching device (1) according to one of paragraphs 2-9, characterized in that the pin (14) is designed with the possibility of movement by means of at least one, preferably two cylinders (19). 11. A switching device (1) according to one of the preceding claims, in which the switching device is designed as a normally open contact, or as a normally closed contact, or as a changeover contact. 12. A switching device (1) according to one of the preceding claims, in which the switching device is designed as a manual disconnector.

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