DE7223330U - Electromagnetic device, in particular special relays - Google Patents

Description

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δ.6.1972 Ws / Kf

Attachment to

Utility model registration

ROBERT BOSCH GMBH, Stuttgart

Electromagnetic device, especially relays

The invention relates to an electromagnetic device, in particular Relay wit an iron core, an excitation winding to generate a magnetic flux in the iron core, an armature, which together with the iron core forms a magnetic circuit and with a magnetic working air gap between the iron core and the armature.

With devices such as solenoids, contactors and relays, it is necessary> that after switching off the

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Robert Bosch GmbH R. 9 \ daily V / s / Kf

Stuttgart

The excitation winding of the armature does not stick to the iron core due to the effect of residual majmetism, but drops off immediately. The tendency of the armature to stick to the iron core is greater ₃ the larger the contacting pole faces, the further the magnetization caused by the excitation winding is moved into the saturation area of the magnetic circuit and the greater the coercive force of the iron core or the armature.

It is known to reduce the undesirable adhesive forces, a working air gap of a certain size between the To insert the iron core and the armature into the magnetic circuit, in the rivet made of non-magnetic steels, made of non-ferrous metals or made of plastic either in the anchor or in the core. It is also known to place thin sheets of non-magnetic metals on the iron core or on the armature to be welded on, riveted or soldered on.

Such solutions require a considerable amount of material and labor and special facilities for drilling the Rivet holes or for soldering or welding. In addition, can the drop-offs us; - this is the voltage on the excitation winding, at which the armature drops - not set precisely enough due to the manufacturing tolerances in the working air gap, so that additional measures are required for this.

The invention is based on the object of using the simplest possible means to reduce the working air gap between the iron core and the anchor on a precise, to achieve a certain Set the required drop-out voltage.

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Robert Bosch GmbH R. 9 I 7 Ws / Kf

Stuttgart

This is inventively achieved in that the working air gap of the magnetic circuit is formed by a the iron core and / or the armature-adhered _s magnetically ineffective film of a certain thickness. The film can consist of plastic or of magnetically inactive metal. The film is glued to the core or anchor with a suitable adhesive.

Details of the invention are explained using an exemplary embodiment shown in the drawing.

The figure shows a relay 1, the connections of which are not visible on the back of a base plate 2 made of insulating material. The base plate 2 carries an iron core 3, which consists of an L-shaped yoke k and a pin 5 riveted to it. An excitation winding 6 is arranged on the pin 5. An armature 7 is hinged to the yoke ^ at the top end, wherein its free end portion extends beyond the end face of the pin. 5 A leaf spring 8 fastened to the yoke k on the one hand and to the armature 7 on the other hand carries a contact 9 * on its end section 8a which projects beyond the armature 7 and which interacts with a mating contact 10 fastened on the base plate 2. When the excitation winding β is switched off, the free end 8a of the leaf spring 8 rests against a stop 11 which is also fastened on the base plate 2 due to the leaf spring preload. In this so-called switch-off position, the armature 7 is lifted from the pin 5 of the iron core 3 and the contacts 9 and 10 are open.

When a voltage is applied to the excitation winding 6, a magnetic flux is built up in the iron core ₃ through the yoke 4,

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Robert Bosch GmbH R. ί 1? Ws / Kf

Stuttgart

is closed by the armature 7 and via an air gap lying between the armature and the end face of the pin 5. The magnetic force generated thereby pulls the armature 7 onto the end face of the pin 5, the contact 9 at the end of the leaf spring 8a with its mating contact 10 in contact. the Contacts 9 and 10 of the relay 1 are closed, although between the armature 7 and the pin 5 of the iron core 3 so-called ArbeitsluftsOalt lies, which is magnetically ineffective by a magnetically ineffective one stuck to the free end section of the armature 7 Foil 12 is formed from plastic. The film 12 is self-adhesive on its side facing the armature 7, see above that they can be attached to the anchor 7 without any special labor is. The size of the required working air gap is determined by the desired drop-out voltage of relay 1 of 6 V. certainly. Compliance with the working air gap is ensured by the thickness of the film 12 of 0.5 mm ensures its manufacturing tolerances are extremely low.

The invention is not limited to the exemplary embodiment, but also includes solutions in which a foil on the iron core or a foil each as anchor and as O iron core is stuck on. The adhesive can be on the anchor or on the iron core as well as on one side applied to the film.

Claims (3)

Robert Bosch GmbH * R. 9 1 7 Ws / Kf Stuttgart. 6.6.1972 claims 1. Electromagnetic device, in particular relay with an iron core, an excitation winding for generating a Magnetic flux in the iron core, an armature that forms a magnetic circuit together with the iron core and with a magnetic working air gap between the iron core and the armature, characterized in that the working air gap of the magnetic circuit through a magnetically ineffective film (12) stuck to the iron core (3) and / or to the armature (7) is formed of a certain thickness'. 2. Electromagnetic device according to claim 1, characterized in that that the magnetically reversible film (12) is self-adhesive on one side. 3. Electromagnetic device according to claim 1 or 2, characterized in that the film (12) consists of plastic, H. Electromagnetic device according to claim 1 or 2, characterized in that the foil (12) consists of magnetically inactive metal,
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