EP2095387B1 - Double break installation switchgear - Google Patents

Description

The invention relates to an installation switching device with a double interruption according to the preamble of claim 1.

Generic installation switching devices, such as motor protection switch, have at least one Polstrompfad, comprising two fixed contacts and two arranged on a movable contact bridge movable contact pieces through which a pole switch with two contacts and double interruption is formed. The contact bridge is acted upon by a pusher in the opening direction and by a contact pressure spring in the closing direction.

Next include generic installation switching devices, such as in DE 195 40 972 A1 discloses an electromagnetic release whose armature strikes the contact bridge in the opening direction when a short-circuit current occurs in the Polstrompfad both via the pusher, as well as the Verklinkungsstelle a switching mechanism unlocks, so that the switching mechanism via a knuckle the contact bridge permanently against the force of the contact pressure spring acts opening ,

Immediately after the strike of the contact bridge and thus the interruption of the short-circuit current in the Polstrompfad the electrodynamic recoil of the electromagnetic release collapses and the contact bridge is acted upon by the force of the contact pressure spring toward its closed position.

Due to the greater mechanical inertia of the switching mechanism, compared with that of the system comprising the armature and the pusher, the active lever for the permanent keeping open of the contacts by the switching mechanism of the pusher movement hurries after.

Under unfavorable conditions, it may happen that the contacts have already been closed again by the contact pressure spring, before the switch lock can cause a permanent opening via the active lever and the pusher. One then speaks of the occurrence of a contact bounce, which is undesirable.

It is therefore an object of the present invention to provide a generic service switching device with improved dynamic behavior in the short-circuit current interruption while avoiding contact bounce.

The object is achieved by a generic service switching device with the characterizing features of claim 1.

According to the invention, therefore, the pusher comprises a slider and a striker, which are arranged substantially displaceable in the direction of movement of the contact bridge relative to this and relative to each other, wherein the arrangement of slide, striker, contact bridge, active lever and armature is arranged so that in case of short circuit, the anchor over the striker the contact bridge opens in the opening direction, the slider lags the striker before the active lever holds the contact bridge against the contact pressure force permanently in the open position on the slide.

The pusher according to the invention is thus designed in two pieces. This makes it possible that a first part of the pusher, namely the striker pin can be accelerated very quickly by the anchor in the event of short circuit due to its small mass and thus very quickly hits the contact bridge.

If the contact bridge has been opened and thus the short-circuit current is interrupted, the force effect of the armature ends on the striker. The contact bridge is now pressed by the force of the contact pressure spring in the closing direction.

The inventively as the second part of the pusher the striker lagging slider can slow this countermovement of the contact bridge, so that the contact bridge is prevented from closing the contacts before the active lever, in the due to the greater mechanical inertia of the switch latch the striker still lags, Finally, the contact bridge is permanently held in the open position via the slide.

Thus, by the service switching device according to the invention a very quick impact of the contact bridge in the event of short circuit while preventing the Kontakttprellens is achieved.

According to a particularly advantageous embodiment, the contact bridge is guided displaceably in a first opening of the slider in its direction of movement.

Very advantageous is a further embodiment in which the striker pin is slidably guided in a second opening of the slider in the direction of movement of the contact bridge. The leadership of the striker pin in the second opening of the slide is advantageously dimensioned so that the striker pin in its opening direction of the contact bridge due to an existing frictional force between striker and slider entrains this in the opening direction lagging.

According to an advantageous further embodiment, the slider in the first opening has a first shoulder, which forms an upper stop for the contact bridge. This ensures a very compact structure. If the slider strikes in its opening direction of the contact bridge in its stroke following the striker pin, then the opposite action of the contact bridge in the closing direction is slowed down by the first shoulder acting as an upper stop.

Advantageously, the slider has on its outer side a second shoulder, which forms a point of application for the active lever.

Further advantageously, the arrangement of striker, slide and contact bridge is dimensioned so that the mass of the slider is equal to or greater than the sum of the masses of striker and contact bridge. This results in the advantage that the force of the return spring on the contact bridge is smaller than the force acting on the contact bridge due to the genetic energy of the striker pin when opening.

Even more advantageous is an embodiment in which the slide in the first, the contact bridge leading opening has a third paragraph, which forms a lower stop for the contact bridge. At the third paragraph takes the contact bridge at its impact movement in the opening direction, the slider initially a piece in the opening direction and thereby supports the pursuit pin lagging movement in the opening direction. If after the collapse of the electrodynamic Rebound of the electromagnetic release, the contact bridge due to the force of the contact pressure spring moves in the opposite direction in the closing direction, so in the embodiment just described, the slider has advanced even further in the opening direction and meets with his first paragraph even earlier on the contact bridge, creating an even more effective braking the opposite closing movement of the contact bridge is done.

Reference to the drawings, in which three embodiments of the invention are shown, the invention and further advantageous embodiments and improvements of the invention will be explained and described in detail.

Figur 1a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker in der Ruhestellung,

Figur 1b:

eine Schnittansicht des erfindungsgemäßen Drückers gemäß Figur 1 a in der Ruhestellung,

Figur 2a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker kurz nach Auftreten eines Kurzschlussstromes,

Figur 2b:

eine Schnittansicht des erfindungsgemäßen Drückers gemäß Figur 2a,

Figur 3a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker bei maximaler Auslenkung der Kontaktbrücke in Öffnungsrichtung,

Figur 3b:

eine Schnittansicht des erfindungsgemäßen Drückers gemäß Figur 3a,

Figur 4a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker bei gegenläufiger Bewegung der Kontaktbrücke und des Schiebers,

Figur 4b:

eine Schnittansicht des erfindungsgemäßen Drückers gemäß Figur 4a,

Figur 5a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker bei Beginn der Wirkung des Schaltschlosses auf den Wirkhebel,

Figur 5b:

eine Schnittansicht des erfindungsgemäßen Drückers in der Position gemäß Figur 5a,

Figur 6a:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker bei dauerhafter Öffnung durch das Schaltschloss über den Wirkhebel,

Figur 6b:

eine Schnittansicht des erfindungsgemäßen Drückers in der Position gemäß Figur 6a,

Figur 7:

eine Schnittansicht eines erfindungsgemäßen Drückers gemäß einer weiteren Ausführungsform, sowie

Figur 8:

eine Schnittansicht eines erfindungsgemäßen Drückers gemäß einer dritten Ausführungsform.

Show it:

FIG. 1a

a functional diagram of a service switching device according to the invention with a pusher according to the invention in the rest position,

FIG. 1b

a sectional view of the pusher according to the invention FIG. 1 a at rest,

FIG. 2a:

a functional diagram of a service switching device according to the invention with a pusher according to the invention shortly after the occurrence of a short-circuit current,

FIG. 2b:

a sectional view of the pusher according to the invention FIG. 2a .

FIG. 3a:

a functional diagram of a service switching device according to the invention with a pusher according to the invention with maximum deflection of the contact bridge in the opening direction,

FIG. 3b:

a sectional view of the pusher according to the invention FIG. 3a .

FIG. 4a

a functional diagram of a service switching device according to the invention with a pusher according to the invention with opposite movement of the contact bridge and the slider,

FIG. 4b:

a sectional view of the pusher according to the invention FIG. 4a .

FIG. 5a

a functional diagram of a service switching device according to the invention with a pusher according to the invention at the beginning of the action of the switching mechanism on the active lever,

FIG. 5b:

a sectional view of the trigger according to the invention in the position according to FIG. 5a .

FIG. 6a:

a functional diagram of an installation switching device according to the invention with a handle according to the invention in permanent opening through the switch lock on the active lever,

FIG. 6b:

a sectional view of the trigger according to the invention in the position according to FIG. 6a .

FIG. 7:

a sectional view of a pusher according to the invention according to a further embodiment, and

FIG. 8:

a sectional view of a trigger according to the invention according to a third embodiment.

In the FIGS. 1 to 8 each identical or equivalent elements or assemblies are each denoted by the same reference numerals.

The FIG. 1 shows an inventive switching device 1 with a Polstrompfad 2 between an input terminal 3 and an output terminal 4. It could for example be a Polstrompfad a three-pole motor protection switch, the other two Polstrompfade are constructed accordingly.

The pole current path 2 comprises two fixed contact pieces 5, 6 and two movable contact pieces 8, 9 arranged on a movable contact bridge 7, through which a contact point 10 with double interruption is formed. The contact bridge 7 is acted upon by a contact pressure spring 11 in the closing direction, see directional arrow S. By a pusher 12 which engages the contact pressure spring 11 opposite side of the contact bridge 7, this can be applied in the opening direction, see direction arrow O.

The Polstrompfad 2 also includes a thermal release 113 and an electromagnetic release 13 with an armature which in the case of occurring in the Polstrompfad 2 short-circuit current due to an electrodynamic recoil on the pusher 12, the contact bridge 7 in the opening direction, indicated by the action line 1.4. At the same time, the armature of the electromagnetic release 13 acts in the event of a short circuit on a switching mechanism 15 and unlocks the Verklinkungsstelle, indicated by the action line 16, so that the switching mechanism 15 in the unlatched state via a knuckle 17, indicated by the action line 18, the pusher 12 permanently in Opening direction of the contact bridge 7 acted upon.

The function of the thermal release 113, which also acts in the case of an overcurrent on the switching mechanism 15, indicated by the action line 114, is known in principle and not the subject of the present invention. The thermal release 113 is shown here only for the sake of completeness.

In the mechanical system comprising the switching mechanism 15 and the active lever 17 may be, for example, a toggle lever system with a two-stage latch. The active lever 17 is designed as a double arm lever whose first, acted upon by the switching mechanism 15 lever arm 171 and the second, cooperating with the pusher 12 lever arm 172 form an obtuse angle with each other and is rotatably mounted in a stationary axis of rotation 173, whereby the active lever 17 as a lever acts.

The mechanical system just described has a certain mechanical inertia, which after unlatching a certain amount of time, for example 2 to 5 ms, passes before the active lever 17 hits the pusher 12 to apply this permanently in the opening direction.

In contrast, the time to direct strike of the contact bridge 7 by the armature of the electromagnetic release 13 is much shorter, it is for example only 1 ms.

This could, if no further action is taken, happen that the contact bridge 7 already pressed back by the restoring force of the contact pressure spring 11 back to its original position in the closed position and the contact point 10 is closed again before even the active lever 17 with the free end of his second arm 171, the pusher and thus the contact bridge 7 can act permanently in the open position.

The measures according to the invention, which are taken to prevent this, are described below.

The pusher 12 is designed in two parts. It comprises a slider 19 and a striking pin 20. As in the sectional view of Figure 1 b can be seen, the pusher 12 is an elongate member having approximately a cylindrical or cuboidal basic shape.

In a first, slot-like opening 21 in the slide 19, which is open down to the narrow side of the slider 19 out, the contact bridge 7 is slidably guided in its closing or in its opening direction.

The striker 20 is also movably guided in the closing or opening direction of the contact bridge 7 in a second, channel-like opening 22 in the slide 19. It projects beyond the slide 19 in the direction of the point of the impact anchor.

In the first opening 21 of the slider 19, a first shoulder 23 is formed, which serves as an upper stop for the contact bridge 7. On the outside of the slider 19, a second shoulder 24 is formed, which serves as a point of attack for the active lever 17.

The function of the arrangement according to the invention when a short-circuit current occurs will now be explained below. If a short circuit current occurs, see FIG. 2a Thus, due to the electrodynamic recoil of the electromagnetic actuator 13, its armature beats on the striker pin 20 of the pusher 12, indicated by the pulse arrow I in FIG FIG. 2a , The striking pin 20 is accelerated in the opening direction O down, taking the contact bridge 7 in the opening direction O. As a result, the movable contact pieces are 8.9 separated from the fixed contact pieces 5.6 and the double pad 10 is opened. Due to the inertia, the downward movement of the striker pin 20 continues, even if the armature returns after breaking the short-circuit current when the contact point 10 is open again in its rest position. The FIG. 3a shows this state in which the contact bridge 7, driven by the striker 20, had reached its maximum deflection in the opening direction O. The contact pressure spring 11 is completely compressed.

Due to a low sliding frictional force between the striker 20 and the slider 19 in the interior of the second opening 22 of the slider 19 is taken by the striker 20 in the opening direction O the striker 20 lagging.

If the maximum deflection of the contact bridge 7 is reached in the opening direction O, this is due to the restoring force of the contact pressure spring 11 again upwards in the closing direction S applied and moved, see FIG. 4a , For a certain time, therefore, an opposite movement of the contact bridge 7 upwards and the slider 19 downwards takes place. When the slider 19 meets with its first paragraph 23 on the approaching contact bridge 7, so initially slows the upward movement of the contact bridge 7, but then after a short delay the contact bridge 7 the slider 19 on its further upward movement in the closing direction on the first paragraph 23 takes. This situation is in the FIGS. 5a and 5b shown.

In the FIG. 5a is that time detected in which the inertia delay of the mechanical system consisting of the switching mechanism 15 and the active lever 17 is completed and designed as a toggle lever 17 is rotated by the switching mechanism 15, indicated by the action arrow K, clockwise. The contact point 10 is still open.

Upon further upward movement in the closing direction S, the slider 19 hits with its second paragraph 24 on the rotating further clockwise active lever 17. The switching mechanism 15 is unlatched, and holds - indicated by the arrow K - the active lever 17 permanently in such a position that he holds on the second paragraph 24 the slider 19 so far in the opening direction O that the contact point 10 remains permanently open. A contact bounce has obviously not occurred.

The opening of the contact bridge 7 through the armature of the electromagnetic release 13 takes place in the manner described above, preferably with small and medium short-circuit currents. At high short-circuit currents, approximately greater than 1 to 2 kA, the opening is located via an electrodynamic repulsion between the fixed and movable contact pieces 5.6; 8,9 instead. It is also called an opening by electrodynamic repulsion between the contact pieces. This opening by e-lektrodynamisch repelling takes place faster than the opening through the anchor, since no mechanically moving intermediate parts, such as the anchor represents involved and therefore no inertia-related time delay occurs. In this case, the armature initially trails the contact bridge. Prevention of premature closing of the pad occurs after the initial rapid opening due to the electrodynamic repulsion, but then in the subsequent time exactly as described above.

The FIG. 7 shows a further embodiment of a slide 19a according to the invention. In this case, the first opening 21 is closed at the bottom by a web 25. The range of movement of the contact bridge 7 is thus limited in the first opening 21 between acting as the upper stop first shoulder 23 and the web 25. The advantageous effect of the web 25 is that during the downward movement of the striker pin 20, this acts as a lower stop and the slider 19 actively takes down in the opening direction. He supported by the trailing entrainment of the slider 19 down in the opening direction O by the striker 20th

Another variant shows the FIG. 8 , There are instead of a continuous web in the first opening 21 at the open end of two paragraphs 26 each with bevelled side surfaces 27 attached. The entrainment of the slide 19 through the contact bridge 7 takes place via the inclined surfaces 27th

Overall, the service switching device according to the invention thus comprises two moving systems. The first moving subsystem comprises the striker 20 and the contact bridge 7, to the second moving subsystem includes the slider 19. The two moving subsystems must be dimensioned so that the force of the contact pressure spring 11 on the contact bridge 7 is smaller than the force that the Striker 20 learns due to the kinetic energy communicated to him from the armature of the electromagnetic actuator 13 by the impact. For this purpose, the mass of the slider 19 must be greater or at least equal to the sum of the masses of the striker pin 20 and the contact bridge. 7

LIST OF REFERENCE NUMBERS

1

Service switching device

2

pole current path

3

input terminal

4

output terminal

5, 6

Fixed contact pieces

7

Mobile contact bridge

8, 9

Movable contact pieces

10

contact point

11

Contact pressure spring

12

handle

13

Electromagnetic release

14

line of action

15

switch lock

16

line of action

17

active lever

18

line of action

19

pusher

20

striker

21

First opening

22

Second opening

23

First paragraph

24

Second paragraph

25

web

26

paragraph

27

Beveled side surfaces

113

Thermal release

114

line of action

171

First lever arm

172

Second lever arm

173

axis of rotation

Claims (9)

1. Installation switching device (1) having at least one pole current path (2), comprising two stationary contact pieces (5, 6) and two moving contact pieces (8, 9) which are arranged on a moving contact bridge (7), by means of which a double-break pole switch with two contacts is formed, with the contact bridge (7) being acted on by a pusher (12) in the opening direction (0) and by a contact compression spring (11) in the closing direction (S), having an electromagnetic release (13) whose impact armature, in the event of a short circuit, not only strikes the contact bridge (7) in the opening direction (0) via the pusher (12) but also unlatches the latching point of a switch latch (15) such that the switch latch (15) permanently acts on the contact bridge (7) in the opening sense, against the force of the contact compression spring (11), via an operating lever (17) which acts on the pusher (12), with the pusher (12) comprising a slide (19) and a striking pin (20) which are arranged such that they can move relative to the contact bridge (7) and relative to one another essentially in the movement direction of the contact bridge (7), characterized in that the arrangement comprising the slide (19), the striking pin (20), the contact bridge (7), the operating lever (17) and the armature is designed such that, in the event of a short circuit, the armature strikes the contact bridge (7) via the striking pin (20) in the opening direction (0), with the slide (19) lagging behind the striking pin (20) in the opening direction as a result of a mechanical interaction which is present between the striking pin (20) and the slide (19) before the operating lever (17) permanently holds the contact bridge (7) in the open position via the slide (19) against the contact pressure force.
2. Installation switching device (1) according to Claim 1, characterized in that the contact bridge (7) is guided in a first opening (21) of the slide (19) such that it can move in its movement direction.
3. Installation switching device (1) according to one of the preceding claims, characterized in that the striking pin (20) is guided in a second opening (22) of the slide (19) such that it can move in the movement direction of the contact bridge (7).
4. Installation switching device (1) according to Claim 3, characterized in that the slide (19) has a first step (23) in the first opening (21), which step (23) forms an upper stop for the contact bridge (7).
5. Installation switching device (1) according to Claim 4, characterized in that the slide (19) has a second step (24) on its outside, which step (24) forms a point of action for the operating lever (17).
6. Installation switching device (1) according to Claim 5, wherein the arrangement comprising the striking pin (20), the slide (19) and the contact bridge (7) is designed such that the mass of the slide (19) is equal to or greater than the sum of the masses of the striking pin (20) and contact bridge (7).
7. Installation switching device (1) according to Claim 5, characterized in that the slide (19) has a third step (26) in the first opening (21), which step (26) forms a lower stop for the contact bridge (7).
8. Installation switching device (1) according to Claim 5, characterized in that the slide (19) has a web (25) at the free end of the first opening (21), which web (25) covers the opening and forms a lower stop for the contact bridge (7).
9. Installation switching device (1) according to one of the preceding claims, characterized in that, in the event of high short-circuit currents, the contact bridge (7) is opened by electrodynamic propulsion between the stationary contact pieces (5, 6) and the moving contact pieces (8, 9), and the impact armature lags behind the contact bridge (7).

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