EP2471084B1 - Attachment module for detection of a switching state of an electromagnetic switching device - Google Patents

Description

The invention relates to an attachment module for detecting a switching state of an electromagnetic switching device having a switch housing, in which an actuator is arranged, which is designed as a plunger and is at one end in operative connection to a switching element, in particular a microswitch.

Electromagnetic switching devices in the context of the present invention are contactors, disconnectors, power relays and circuit breakers. For such electromagnetic switching devices, in particular for contactors, it is necessary in a large number of applications to detect the actual switching state of the electromagnetic switching device, in contrast to a driving state of the electromagnetic switching device, in order to be able to evaluate it elsewhere.

The information in which switching position an electromagnetic switching device, in particular a contactor, is, has hitherto been accomplished by a star-delta connection. The electrical interlocking of two coupled contactors has hitherto been realized via auxiliary contacts, which must be wired in the same way as the star-delta connection.

In the prior art, such a switching state detection takes place by means of a detection device. Here, a mechanical switching contact is arranged in the housing, which changes its switching state when transferring the plunger from one to the other end position. The switching contact is connected via lines to an evaluation device, so that the switching position of the switching contact and thus the switching state of the electromagnetic switching device can be detected by the evaluation device. In most cases, the detection device is its own, from the electromagnetic switching device different device, for example a so-called auxiliary switch.

This is from the DE 10 2007 002 176 A1 a detection device for detecting the switching state of an electromagnetic switching device, which has a housing in which a plunger is movably mounted. The plunger is movable between two mechanical end positions, wherein the end position of the plunger corresponds to the switching state of the electromagnetic switching device. In the housing, a sensor device is arranged, from which it can be detected, in which of the end positions the plunger is located, and from which a corresponding electrical signal can be emitted. The sensor device is designed such that the position of the plunger can be detected by it, without touching the plunger. On the housing, a tapping connection is also arranged, which is accessible from outside the housing and over which the electrical signal emitted by the sensor device can be tapped off as such. In addition, a conditioning circuit is arranged on the housing, which prepares the electrical signal emitted by the sensor device in a message and outputs the message via a communication port.

A disadvantage of the prior art is that only two different switching states, the on and the off state, can be displayed via the detection device. The switching state in which the contacts are welded in the electromagnetic switching device, so far can not be reproduced via a switching state indicator.

Accordingly, the object of the present invention is to provide a top module for detecting a switching state of an electromagnetic switching device, which is designed such that it reflects three possible switching states of the switching device, the on and off state and the switching state in welded contacts.

This object is achieved by an attachment module having the features of patent claim 1. Advantageous embodiments and developments, which can be used individually or in combination with each other, are the subject of the dependent claims.

This object is achieved by an attachment module for detecting a switching state of an electromagnetic switching device having a switch housing in which an actuator is arranged, which is designed as a plunger and is at one end in operative connection with a switching element, in particular a microswitch. The invention is characterized in that the plunger has a snap hook at the other end, which communicates three possible switching positions of the electromagnetic switching device to the microswitch. The electromagnetic switching device may be a contactor, which has a coil which can be acted upon by a switching current IS. When the switching current IS is applied to the coil, it attracts an armature. When the switching current IS is interrupted, the armature moves away from the coil due to a restoring spring force. The armature is connected to a plunger. Therefore, together with the armature, the plunger is also attracted to the coil. Due to the movement of the plunger, at least one load contact is closed so that a load current IL can flow. Conversely, when the switching current IS is interrupted, the load contact is opened again.

Alternatively, the electromagnetic switching device may for example also be a power switch. In this case, the switching current IS is identical to the load current IL. The coil in this case attracts the armature when the load current IL becomes too large. Due to the tightening of the armature a switching lock is released, which moves the plunger in a position in which the load contact remains open. The position of the plunger is designed so that it corresponds to the state of the load contact and thus with the switching state of the electromagnetic switching device, regardless of the specific configuration of the electromagnetic switching device. According to the invention, the plunger three possible switching positions of the electromagnetic switching device, the input and exhibition and the switching position in welded contacts indicate. Accordingly, the switching position of the contactor is transmitted via the plunger as a mechanical switching position display directly into the module. At the switching position indicator is a nose, which thus when switching the contactor a switching element, in particular a micro switch, operated in the attachment module. In order to realize the mutual locking of two electromagnetic switching devices, in particular two contactors, via this switching element, the drive signal of the respective other contactor is guided via the switching element in the attachment module of the first contactor. Advantageously, the locking is thus no longer via auxiliary contacts of the contactor, but via the switching element in the module. This has the advantages that the auxiliary contact in the contactor is at the customer's free disposal, and he no longer has to make any wiring. The devices are also pre-assembled in total, so that the potential for errors can be minimized.

It is inventively provided that the plunger is connected at one end to the microswitch and at the other end has a snap hook, which occupies three different positions relative to a reference edge to the different switching states, the on and off state and the switching state to show welded contacts.

In a particularly advantageous embodiment, the attachment module has a communication cable, which enables transmission of activation signals between two attachment modules. In this case, it is further advantageously provided that in the mutual locking of two mutually coupled electromagnetic switching devices, in particular two contactors, the drive signal of a contactor is guided via the switching element in the attachment module of the other contactor.

Further advantages and embodiments of the invention will be explained below with reference to embodiments and with reference to the drawing

• Fig. 1 in einer Schnittdarstellung ein erfindungsgemäßes Aufsatzmodul zum Erfassen eines Schaltzustandes eines elektromagnetischen Schaltgeräts;
• Fig. 2 in einer Schnittdarstellung das erfindungsgemäße Aufsatzmodul nach Fig. 1 mit Kommunikationskabel;
• Fig. 3 in einer schematischen Darstellung die drei unterschiedlichen Schaltstellungen des Schnapphakens für die drei unterschiedlichen Zustände des elektromagnetischen Schaltgeräts.

Here are shown schematically:

• Fig. 1 in a sectional view of an inventive attachment module for detecting a switching state of an electromagnetic switching device;
• Fig. 2 in a sectional view of the attachment module according to the invention Fig. 1 with communication cable;
• Fig. 3 in a schematic representation of the three different switching positions of the snap hook for the three different states of the electromagnetic switching device.

Fig. 1 shows an inventive attachment module 1, which has an upper housing part 2, which is fastened via locking elements 3 on the outer housing 4. From the upper housing part 2 protrudes into the housing interior, a guide unit 5, in which a plunger 6 is mounted. The attachment module 1 sits on a protective device (not shown), preferably a contactor, wherein the attachment module 1 and the protective device via a snap hook 7 are in operative connection with each other when it comes to the triggering process. The plunger 6 is actuated during the tripping operation via a spring element 8 a switching element 9. The transmission from the plunger 6 to the spring element 8 via a hook-like projection 10 on the plunger 6. The switching element 9 has connection elements 11 for printed circuit boards. In attachment module 1 also plug connections 12 and further electrical components 13 are arranged.

Fig. 2 shows the attachment module 1 in a particularly advantageous embodiment with integrated communication cable 14, the transmission of drive signals between two Attachment modules allows. As a result, in the mutual locking of two mutually coupled electromagnetic switching devices, in particular two contactors, the drive signal of a contactor via the switching element in the attachment module of the other contactor are performed.

In Fig. 3 are the three possible switching states, the on and off state and the switching state in welded contacts in the electromagnetic switching device, shown that are communicated via the snap hook 7 on the plunger 6 the switching element 9. The snap hook 7 changes its position relative to a reference edge 15 corresponding to the three possible switching positions in the electromagnetic switching device. In the Fig. 3 is shown that the snap hook 7 assumes its position relative to the reference edge 15 according to the direction of movement 16 in three defined positions 17, 18, 19 and thereby indicates the on and off state and the switching state in welded contacts.

The present invention offers two key advantages. On the one hand, the three possible switching positions of an electromagnetic switching device, the on and off state and the switching state in welded contacts are precisely displayed by the attachment module according to the invention. On the other hand, no auxiliary contact is needed for the mutual locking of two electromagnetic switching devices, so that the wiring effort is reduced and the auxiliary contact can be used elsewhere.

Claims (4)

1. Attachment module for detection of switching states of an electromagnetic switching device, having a switch housing, in which is arranged an actuator, which is embodied as a plunger (6) and at one end is in operative connection with a switch element (9), in particular a microswitch, wherein the plunger (6) has a snap-action hook (7) at the other end, characterised in that the snap-action hook (7), via the plunger (6), communicates the three different switching statuses of the electromagnetic switching device, the 'on' and 'off' status and the switching status in the case of welded contacts to the switch element (9).
2. Attachment module according to claim 1, characterised in that the snap-action hook (7) takes up the three different positions (17, 18, 19) relative to a reference edge (15).
3. Attachment module according to one of the preceding claims, characterised in that the attachment module (1) has a communication cable (14), which enables the transmission of triggering signals between two attachment modules.
4. Attachment module according to one of the preceding claims, characterised in that in the case of the interlocking of two intercoupled electromagnetic switching devices, in particular two contactors, the triggering signal of the one contactor is routed via the switch element (9) in the attachment module of the other contactor.

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