EP3224852A1 - Switching device having a drive for functional switching and a high-speed circuit breaker for breaking a current path in the switching device - Google Patents

Abstract

The invention relates to a switching device for the on-off switching of a current passing through a current path, having at least one fixed contact (11, 12) and at least one movable contact (14, 15), wherein the movable contact can be moved relative to the fixed contact for making or breaking the current path (10), and a drive (1) for the functional movement of a jumper (17) between a contact-making position and a contact-breaking position, wherein in the contact-making position with the fixed contact the movable contact (14, 15) makes the current path, and having a high-speed circuit breaker (2) for breaking the current path in the event of a short circuit or overload, wherein the armature (4) of the high-speed circuit breaker (2) is rigidly coupled to the movable contact (14, 15).

Description

 Switching device with a drive for operational switching and with a quick release for disconnecting a current path in the switching device

The invention relates to a switching device for switching on and off of a current through a current path, with at least one fixed contact and at least one moving contact, wherein the moving contact for closing and separating the current path relative to the fixed contact is movable with a drive for operationally moving a jumper between a Closed position and an open position, wherein the moving contact in the closed position with the fixed contact closes the current path, and with a quick release for disconnecting the current path in the event of a short circuit or overload.

Such switching devices with corresponding, usually electromagnetic drives are used for example in motor starters. These should be suitable for the operational switching of a load, switching off an overload and switching off in the event of a short circuit. Basically, two separate switching devices, namely a motor protection switch can be used as a circuit breaker and a contactor as a load switch to achieve this functionality. As an alternative, motor starters are known in which the switching and protective function is integrated in a switching device. As a rule, they have a hand-operated, mechanical switch lock. The publication WO 2014/023326 AI a switching device or a drive for a switching device for a compact and remotely controllable motor starter is described with the operational switching of the load, switching off the overload and shutting off short circuits with only one device to be realized , The problem with switching off short circuits is the need to open the closed contacts very quickly and permanently, so that a safe extinguishing of the arc is ensured, and a re-ignition of the arc and welding of the contacts can be avoided. The drive has for this purpose a bipolar electromagnetic drive unit with a movable armature and two stationary magnetic coils for reversible movement of the armature between two permanent magnetically stabilized anchor layers, wherein by selective Excitation of the first magnetic coil, a moving contact is movable into the closed position and by selective energization of the second magnetic coil of the moving contact within a permissible for a short circuit in the current path Maximalabschaltzeit in the open position is movable.

Electromagnetic actuators that are used for switching on and off, have the disadvantage that they have a comparatively large, moving mass, which is necessary for the switch-on. Due to the inertia, however, such a drive has a correspondingly long turn-off time. The switch-off times that can be achieved in this way may be too long to safely switch off a short circuit.

An object of this invention is to provide a switching device for turning on and off a current through a current path with a quick release for disconnecting the current path, with which the switching off of an overload and the switching off of short circuits, regardless of a turn-off time of the drive for operational switching, fast and safe feasible and which allows a compact, space-saving design.

The object is solved by the subject of the main claim. In the dependent claims preferred embodiments and advantageous developments are given.

The switching device according to the invention for switching on and off a current through a current path has at least one fixed contact and at least one moving contact, wherein the moving contact for closing and separating the current path relative to the fixed contact is movable. Such a contact system may have a single contact pair. It is preferably carried out in a double-interrupting manner, wherein two moving contacts are connected in particular via a moving contact carrier in order to be movable relative to two fixed contacts of the current path. In the following, the terms moving contact and fixed contact will be used without going into the possibility of an embodiment with a double-break contact system, since this is familiar to the person skilled in the art. In this respect, a moving contact carrier with two moving contacts is covered by the term moving contact. The switching device according to the invention further comprises a drive for operationally moving a switching bridge between a closed position and an open position, the moving contact in the closed position with the fixed contact closes the current path, so that the drive is also generally referred to as a drive for operational switching of the switching device.

Furthermore, the switching device according to the invention on a quick release for disconnecting the current path in the event of a short circuit or overload. Both the drive for operational switching of the switching device, as well as the drive of the quick release are preferably electromagnetic drives.

According to the invention, it is provided that the moving contact is movably guided along the switching bridge between a first stop and a second stop and is rigidly coupled to an armature of the quick release.

An advantage of the switching device according to the invention is that the moving contact movably guided along the switching bridge can be separated from the fixed contact in the closed position of the switching bridge in the event of a short circuit by the quick release. The person skilled in the art knows that, in the event of a short circuit, the lifting of the moving contacts is generally initially caused by the electrodynamic lifting forces and the quick release preferably prevents the moving contacts from falling back and further removes them from the fixed contacts. This exploitation of the known electrodynamic lift-off forces when switching off short-circuit currents is not necessarily described here in connection with the triggering of the quick release. The rigid coupling between the quick release and the moving contact provides, moreover, advantageous for accelerated release of the quick release, as an air gap in the quick release is so already reduced due to the electrodynamic lift. Furthermore, the rigid coupling allows resetting the permanently open after a trip moving contact with a simultaneously advantageously space-saving design and / or arrangement of the quick release and / or the drive for operational switching.

According to a preferred embodiment, it is provided that the armature of the quick release is biased by means of an impression spring, so that the moving contact through the impression spring is biased in the direction of the first stop of the switching bridge. Particularly preferably, it is provided that the impression spring of the armature simultaneously acts as a contact pressure spring of the moving contact. In the closed position of the switching bridge of biased in the direction of the first stop moving contact with the fixed contact closes the current path, so that the impression spring of the armature simultaneously acts as a contact pressure spring of the moving contact. A separate contact pressure spring is thereby advantageously saved.

In the closed position of the switching bridge is further preferred moves the biased in the direction of the first stop moving contact at a short circuit or overload by the quick release against the first stop opposite to the contact bridge arranged second stop moves, so that the current path is disconnected. In the event of a short circuit, the first lifting of the moving contacts is generally caused by the electrodynamic lifting forces before the quick release prevents the moving contact from falling back and moving it further in the direction of the second stop.

According to a further preferred embodiment, provision is made for a holding device to be provided on the switching bridge in order to hold the moving contact, which is separated by the quick release, against the second stop. An advantage of this embodiment is that even with a reduction of the excitation current of the quick release due to the deletion process, the current path remains disconnected. A falling back of the moving contact, a reignition of the arc or even a welding of the moving contact with the fixed contact can be advantageously avoided.

The holding device preferably has a permanent magnetic system to keep the moving contact after triggering the quick release with a magnetic force against a spring force of the impression spring on the second stop, wherein an amount of magnetic force is greater than an amount of spring force. Since the moving contact is brought by the quick release in direct contact with the second stop, the magnetic force of the holding device can advantageously act without air gap on the moving contact. Preferably, the at least one moving contact is arranged on a moving contact carrier made of a magnetically conductive material, in particular attached thereto. Particularly preferably, it is provided that the moving contact carrier made of a clad material with a first layer of a copper material and a second layer of a Iron material exists.

According to a further preferred embodiment, it is provided that resetting of the moving contact takes place after a triggering of the quick release by a switch-off operation of the drive for the operational movement of the switching bridge. This saves a separate mechanism for resetting the quick release after a trip.

For this purpose, a counter-stop preferably limits the range of movement of the moving contact in a switch-off of the drive, wherein the moving contact reaches the counter-attack only after a previous triggering of the quick release, so after disconnecting the current path through the quick release. In normal operation, without triggering the quick release by a short circuit or overload, the counter stop does not affect the movement of the moving contact. Particularly preferred forms a core of the quick release with the anchor counter-attack. The movement of the moving contact is thus limited in particular by the fixed contact on the one hand and, after triggering the quick release, by the counter-stop on the other hand to a range of motion. After a release of the quick release, the open position of the switching bridge is achieved due to the counter-attack only after previous release of the moving contact of the holder. For this purpose, a greater resultant force than the holding force of the holding device is necessary. This resulting force is composed of a force of the contact pressure spring and a force of the drive for operationally moving the switching bridge together. The force of the drive to operate the switching bridge is usually provided by an impression spring. The invention will be explained in more detail by means of embodiments with reference to the accompanying drawings. The embodiments are merely exemplary and do not limit the general inventive concept.

Show it

Figure 1 is a schematic representation of a switching device according to the invention; Figure 2 is a detailed view of a portion of an embodiment of the switching device of Figure 1 in an off state;

Figures 3A and 3B are detailed views of portions of the embodiment of Figure 2 in an on state;

Figures 4A and 4B are detailed views of portions of the embodiment of Figure 2 in a separated by the triggered quick release state; a detailed view of a portion of the embodiment of Figure 2 in a state of resetting the quick release.

1 shows a simplified schematic representation of the switching device according to the invention is shown with an exemplary structure. The switching device for switching on and off of a current through a current path 10 has for this purpose two fixed contacts 1 1, 12 which cooperate with two moving contacts 14, 15 on a moving contact carrier 16 for closing and separating the current path 10. An electromagnetic drive 1 is used for operationally moving a switching bridge 17 between a closed position and an open position, wherein the Bewegkontaktträger 16 is guided by the switching bridge 17, which will be discussed in more detail in connection with the following figures. A quick release 2 for disconnecting the current path 10 in the event of a short circuit or overload is also shown only schematically, the exact structure and the functions will be described below with reference to the other figures. The shutting down of shorts requires a very fast and permanent separation of the moving contacts 14, 15 of the fixed contacts 11, 12. In short-circuit currents, the elimination is done by the quick release 2, wherein a first lifting of the moving contacts 14, 15 is caused by electrodynamic lifting forces. By separating the moving contacts 14, 15 of the fixed contacts 11, 12 arcs arise, which are each passed into extinguishing systems 21.

The structure of an embodiment of the switching device according to the invention is explained in more detail below with reference to Figures 2, 3A and 3B. FIG. 2 shows a detailed illustration of a partial region of the switching device in an off state, and FIGS. 3A and 3B show detailed illustrations of partial regions of the switching device in an on state. Of the electromagnetic drive 1 for operationally moving a switching bridge 17 is simplistic only a drive armature 1 is shown, which is biased by an unillustrated impression spring in the direction of a position shown in Figure 2 and at a switch-on by a magnetic coil, not shown in the direction of 3A is moved position shown. The construction of a corresponding contactor drive 1 is well known to those skilled in the art.

The drive 1 is provided for operationally moving the switching bridge 5 between a closed position and an open position, wherein the switching bridge 17 is shown in Figure 2 in the open position, in which the moving contacts 14, 15 are arranged away from the fixed contacts 11, 12, the Rung 10 is disconnected. The moving contacts 14, 15 are arranged at opposite ends of the moving contact carrier 16, which in turn is movably guided along the switching bridge 17 between a first stop 18 and a second stop 19. With the switching bridge 17 in the open position according to Figure 2 are the moving contacts 14, 15, and the connecting Bewegkontaktträger 16, to the first stop 18 of the switching bridge 17, thereby closing the current path 10 is prevented. The moving contacts 14, 15 are biased by a contact pressure spring 5 against the first stop 18, which will be discussed in more detail later in connection with the description of the quick release 2. In a switch-on of the electromagnetic drive 1 is activated and moves the switching bridge 17 in its closed position, which is shown in Figure 3A. The movement of the switching bridge 17 causes a contacting of the moving contacts 14, 15 with the fixed contacts 11, 12, so that the current path 10 is closed. The biased by the contact pressure spring 5 Bewegkontaktträger 16 is no longer at the first stop 18 of the switching bridge 17 at. An operational switch-off is carried out accordingly by the drive 1 is deactivated, so that the unillustrated impression spring of the drive 1, the switching bridge 17 moves back into the open position. The first stop 18 of the switching bridge 17 takes the arranged on the Bewegkontaktträger 16 moving contacts 14, 15 with and separates them from the fixed contacts 11, 12. The resulting Arcs are, as described in connection with Figure 1, performed in corresponding extinguishing systems 21.

The quick release 2 is arranged opposite the drive 1 for operational switching, so that the current path 10 runs between the drive 1 and the quick release 2. As a result, a particularly compact design of the switching device can be realized. The quick release 2 for disconnecting the current path 10 in the event of a short circuit or overload has a core 9, a yoke 3, an armature 4 and a magnet coil 7. The armature 4 is connected via a rigid coupling 8 with the moving contacts 14, 15 on the moving contact carrier 16. This makes it possible for the quick release 2 to disconnect the current path 10, while the switching bridge 17 is in the closed position according to FIG. 3A. The contact pressure spring 5, which biases the moving contacts 14, 15 against the first stop 18 of the switching bridge 17, or against the fixed contacts 11, 12, simultaneously represents the impression spring 5 for the armature 4 of the quick release 2. The spring force is applied via the armature and the rigid connection 8 transmitted to the Bewegkontaktträger 16 with the Bewegkontakten 14, 15.

In FIG. 3B, the switching bridge 17 is shown enlarged in the closed position according to FIG. 3A. Here it can be seen that the moving contact carrier 16 is guided between the first stop 18 and the second stop 19 along the switching bridge 17. When the current path 10 is closed, the movement of the Bewegkontaktträgers 16 in the direction of the closed position is limited by the voltage applied to the fixed contacts 11, 12 moving contacts 14, 15, while the first stop 18 is further moved by the drive 1, so that a gap between the first Stop 18 on the switching bridge 17 and the moving contact carrier 16 is formed.

At the second stop 19, a holding device 20 is provided to hold the separated by the quick release 2 moving contacts 14, 15 to the second stop 19. The triggering of the quick release 2 will be further explained below with reference to FIGS. 4A and 4B. A current flowing through the magnetic coil 7 tripping causes the triggering of the quick release 2, so that the armature 4 is attracted and the moving contacts 14, 15 are moved on the moving contact carrier 16 of the fixed contacts 11, 12 via the rigid connection 8. The switching bridge 17 is still in the closed position, the However rung 10 is disconnected by the triggered quick release 2. This means that the moving contacts 14, 15 are no longer in contact with the fixed contacts 11, 12, since they have been separated from the armature 4 on the moving contact carrier 16 via the rigid connection 8. The actual loosening of the moving contacts 14, 15 takes place as a rule by the action of electrodynamic lifting forces, before the quick release 2, the moving contacts 14, 15 away from the fixed contacts 11, 12 away, to avoid reignition of the switching arc or welding of the contacts.

The moving contacts 14, 15 on the Bewegkontaktträger 16 are after triggering on the second stop 19 of the switching bridge 17, as can be seen in particular in the enlarged view of Figure 4B. By separating the current path 10 and deriving the resulting arcs between the Bewegkontakten 14, 15 and the fixed contacts 11, 12 in corresponding extinguishing systems 21 (see Figure 1), the excitation current decreases through the magnetic coil 7, so that the impression spring 5 of the armature. 4 the moving contacts 14, 15 could move back in the direction of the fixed contacts 11, 12. In order to prevent this, in the illustrated embodiments, the holding device 20 is provided on the second stop 19 of the switching bridge 17, which prevents a loosening of the moving contacts 14, 15 with the Bewegkontaktträger 16 of the stop 19. As a holding device 20 is used in the illustrated embodiment, a permanent magnet system whose magnetic force is sufficient to hold the voltage applied to the stop 19 Bewegkontaktträger 16 against the pressure of the impression spring 5. As a result, a safe switching off of short-circuit currents is ensured and a reignition of the switching arc or welding of the contacts is avoided. The moving contact carrier 16 is in particular made of a magnetically conductive material, preferably of a plated material with a first layer 22 of a copper material and a second layer 23 of a ferrous material.

Another advantage of the switching device according to the invention is that the triggered quick release 2 can be particularly easy to reset to its initial state by the drive 1, the switching bridge 17 moves from the closed position to the open position. The reset operation of the quick release 2, which is shown in Figure 5, thus takes place advantageously by a switch-off, as has been previously described in connection with Figures 2, 3A and 3B. To reset the quick release 2 For example, the moving contacts 14, 15 on the moving contact carrier 16 must be released from the second stop 19 with the holding device 20. For this purpose, the movement of the moving contacts 14, 15 is limited to the Bewegkontaktträger 16 in the direction of the open position of the switching bridge 17 by a counter-stop 6, which is arranged so that the open position of the switching bridge 17 is not yet reached. The counter-stop 6 causes a release of the Bewegkontaktträgers 16 of the second stop 19, so that the switching bridge 17 can reach the open position again. The effect of the counter-stop 6 is given only after triggering the quick release 2, since the Bewegkontaktträger is held only in this case by the holding device 20 to the second stop 19.

In the figure 5 exactly the position of the switching bridge 17 is shown, in which the moving contacts 14, 15 have reached their defined by the stop 6 end position. The stop 6 is realized in the illustrated embodiment in the form of a core 9 of the quick release 2, to which the armature 4 abuts. However, the stop 6 can also be realized in other ways, for example by a separate stop outside the switching bridge 17 against which the moving contact carrier 16 is moved. The switching bridge 17 has not yet reached its open position (see FIG. 2) in the position shown in FIG. 5, so that the drive 1 moves the switching bridge 17 still further into the open position, as a result of which the moving contacts 14, 15 on the moving contact carrier 16 over the rigid connection 8 and the armature 4 are separated from the second stop 19 with the holding device 20, since the additional force through the drive 1 together with the force of the impression spring 5 exceeds the magnetic force of the holding device 20. Thereafter, the switching device again reaches the position shown in the figure 1 with the switching bridge 17 in the open position and the Bewegkontakten 14, 15, which are biased by the contact pressure spring 5 against the first stop 18 of the switching bridge 17. The switching device is thus ready for another switch-on. LIST OF REFERENCE NUMBERS

1 drive for operational switching of the switching device

2 quick release

 3 yoke of the quick release

 4 anchors

 5 impression spring and contact pressure spring

 6 counter-attack

 7 magnetic coil

 8 rigid coupling

 9 Core of the quick release

 10 current path

 11 fixed contact

 12 fixed contact

 14 moving contact

 15 moving contact

 16 moving contact carrier

 17 switching bridge

 18 First stop

 19 Second stop

 20 holding device

 21 extinguishing system for electric arc

 22 First shift

 23 Second shift

Claims

claims 1. Switching device for switching on and off of a current through a current path, with at least one fixed contact (11, 12) and at least one moving contact (14, 15), wherein the moving contact for closing and separating the current path (10) relative to the fixed contact is movable with a drive (1) for operating a switching bridge (17) between a closed position and an open position, wherein the moving contact in the closed position with the fixed contact closes the current path, and with a quick release (2) for disconnecting the current path in the event of a short circuit or at an overload, characterized in that the moving contact (14, 15) along the switching bridge (17) between a first stop (18) and a second stop (19) movably guided and rigidly coupled to an armature (4) of the quick release (3). 2. Switching device according to claim 1, characterized in that the armature (4) by means of a Impression spring (5) is biased so that the moving contact (14, 15) by the impression spring (5) in the direction of the first stop (18) of the switching bridge (17) is biased. 3. Switching device according to claim 2, characterized in that the impression spring (5) of the Anchor (4) acts as a contact pressure spring of the moving contact (14, 15). 4. Switching device according to one of claims 2 or 3, characterized in that in the closed position of the switching bridge (17) biased in the direction of the first stop moving contact (14, 15) in the event of a short circuit or overload by the quick release (2 ) is moved against the first stop (18) arranged opposite to the switching bridge, the second stop (19), so that the current path (10) is disconnected. 5. Switching device according to one of the preceding claims, characterized in that a holding device (20) on the switching bridge (17) is provided to the by the quick release (2) separate moving contact (14, 15) on the second stop (19) hold. 6. Switching device according to claim 5, characterized in that the holding device (20) has a permanent magnetic system to the moving contact (14, 15) after triggering the quick release (2) with a magnetic force against a spring force of the impression spring (5) on to hold the second stop (19), wherein an amount of the magnetic force is greater than an amount of the spring force. 7. Switching device according to one of the preceding claims, characterized in that the at least one moving contact (14, 15) is arranged on a Bewegkontaktträger (16) made of a magnetically conductive material. 8. Switching device according to claim 7, characterized in that the Bewegkontaktträger (16) consists of a clad material with a first layer (22) of a copper material and a second layer (23) of a ferrous material. 9. Switching device according to one of claims 5 to 8, characterized in that a Resetting of the moving contact (14, 15) after a triggering of the quick release (2) by a switch-off of the drive (1) for operationally moving the switching bridge (17). 10. Switching device according to one of the preceding claims, characterized in that in the Öffhungsstellung the switching bridge (17) of the second stop (19) outside a range of movement of the Bewegkontakts (14, 15). 11. Switching device according to claim 10, characterized in that a counter-stop (6) the range of movement of the moving contact (14, 15) at a switch-off of the Limited drive (1), wherein the moving contact reaches the counter-attack only after a previous separation of the current path (10) by the quick release (2). 12. Switching device according to claim 11, characterized in that a core (9) with the armature (4) of the quick release (2) forms the counter-stop (6). 13. Switching device according to one of claims 5 to 12, characterized in that a resultant force of a force of the contact pressure spring (5) and a force of the drive (1) for operationally moving the switching bridge (17) is sufficient to the moving contact (14, 15) from the holding device (20) to solve.