EP0252343B1 - Method of adjusting an electromagnetic relay and a relay adjustable according to this method - Google Patents

Abstract

The response and extinction voltage of a relay are adjusted by displacing an armature, on the one hand, and pole plates, on the other hand, parallel to each other. The extent of each opposing pole face is varied without varying the air-gap distance. This method of calibration is of particular advantage in relation to a reed relay with a bridge contact.

Description

The invention relates to an adjustment method for setting the switching characteristics of an electromagnetic relay, in which at least one flat pole plate and one armature opposite the spring plate with a predetermined air gap with overlapping pole faces are arranged in a housing, resilient or spring-loaded armature.

In addition, the invention relates to a correspondingly adjustable relay.

In the case of relays with spring-loaded armatures, it is usually necessary to change the spring force acting on the armature by bending the spring in order to achieve the desired characteristic values of the relay, i.e. usually the voltage values at which the relay responds or drops out Bring area and thereby compensate for all possible manufacturing tolerances. Bending on an armature return spring is not only complex, but also changes the spring properties, which can have an effect on the service life, for example.

However, if the armature is at the same time a contact element, as is the case with reed contacts, the response values can only be set to a limited extent by bending the armature, since bending would also change the contact spacing with correspondingly undesirable consequences. If there are also anchors and pole plates in a closed contact space, the possibility of adjusting the bend is only possible with a special construction and with special processes. For example, in the case of a multiple contact, as shown in DE-OS 20 59 390, the armature and its bearing spring are no longer accessible after the contact space has been closed. Only after completion of the contact and its insertion in a relay, the response or. Relapse values are checked and evaluated for a targeted comparison to compensate for manufacturing tolerances.

The object of the invention is to provide an adjustment method of the type mentioned at the outset, which can also be used with armature contacts and in closed contact spaces and with which an adjustment of the characteristic values of a relay after assembly and thus to allow for all manufacturing tolerances. More precisely, this method is intended to enable the relay characteristic values, in particular the response voltage and the dropout voltage of the relay, to be set within a narrow range. In addition, the invention is intended to provide a relay suitable for the use of this method.

According to the invention, the above-mentioned object is achieved in an adjustment method of the type mentioned at the outset by first fixing only the pole plate or the armature in the housing, while the other of these elements in a guide slot of the housing while maintaining the specified air gap, but parallel to the pole faces Slidably arranged, remains that by gradually moving the displaceable element the overlap area of the pole faces is changed and in each case the characteristic values for the response and / or falling of the relay are measured and that the displaceable element is fixed in the housing when the measured characteristic values are within a predetermined range Range.

In the method according to the invention, therefore, neither the armature nor the spring used for armature mounting is bent.

Rather, the pole area is varied without changing the air gap distance. Since the parallel displacement of pole sheet or

Pole plates and armature against each other in guide slots, namely in the longitudinal direction of the pole plates or the armature, this type of adjustment is also possible in a closed, if not yet completely sealed, contact space. Such guide slots can also be subsequently sealed in a simple manner.

In a preferred manner, the invention can be applied to a relay in which two pole plates are arranged at a distance from one another with their free ends at a distance from one another and the armature is arranged approximately parallel to the free ends of both pole plates, forming an overlap region in each case. In this case, either one or both pole plates or the armature is expediently first arranged displaceably in the housing, displaced after assembly in the manner mentioned and fixed only after the desired characteristic values of the relay have been reached.

In one embodiment of the mentioned contact relay, the armature is slidably supported in the guide slot of the housing by means of a resilient support relative to both pole plates and is fixed after the desired characteristic values have been reached. The armature or the support is preferably guided in the housing such that a displacement only in the direction the longitudinal axis of the armature and the pole plates is possible. This means that the overlap area between the armature and a first pole plate is increased and at the same time the overlap area between the armature and the second pole plate is reduced or vice versa. However, it would also be conceivable to make the armature displaceable relative to the longitudinal direction of the pole plates, in which case a change in the same direction of the overlap surfaces could be achieved with both pole plates.

In a particularly preferred embodiment of a relay according to the invention, the pole plate or the pole plates are embedded in a first housing part, then the resilient carrier carrying the armature is inserted into a groove formed between the first housing part and a second housing part insert the two housing parts, then a coil winding is applied over the assembled housing parts, then the armature is adjusted by moving the carrier in the groove relative to the pole plates, whereby the response or dropout voltage of the relay are measured, and finally after reaching the desired response or Drop voltage of the anchor girders fixed by pouring liquid plastic.

A relay for applying the method according to the invention has a two-part coil body serving as a housing, a contact space being formed in the interior of the coil body by trough-shaped recesses in both coil body parts, and also two having their free ends embedded in one plane in the one coil body part with their free ends in the contact space opposing pole plates and a flat armature supported in the contact space via a resilient carrier, and a winding applied over both coil former parts. Both coil former parts are molded from plastic, in the separation area between the two coil former parts there is a groove at least on two opposite sides of the contact space, in which the armature carrier is arranged at a predetermined distance parallel to the plane of the pole plates, but within its main plane with play. and the anchor bracket is fixed in the groove by additional means.

In an expedient embodiment, the anchor carrier has a frame shape and is arranged and fixed in a circumferential groove which at least in one direction exceeds the length of the anchor carrier, the anchor being fastened to a tongue which extends inwards from one side of the frame. In a modified embodiment, however, the anchor can only be held with part of a frame or with only one web. In addition, the armature carrier can have an integrally formed adjustment web which extends from the armature carrier in the direction of the outside of the coil body and is accessible from the outside at least before the armature carrier is fixed.

• Fig. 1 und 2 eine schematische Darstellung des erfindungsgemäßen Abgleichverfahrens,
• Fig. 3 ein elektromagnetisches Relais zur Anwendung des erfindungsgemäßen Abgleichverfahrens in perspektivischer, teilweise geschnittener Darstellung,
• Fig. 4 einen Ankerträger mit Anker und einen Gehäuseteil des Relais von Fig. 3,
• Fig. 5 und 6 eine weitere Ausführungsform eines Ankerträgers mit Anker in Seitenansicht und Draufsicht.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. Show it

• 1 and 2 is a schematic representation of the adjustment method according to the invention,
• 3 shows an electromagnetic relay for using the adjustment method according to the invention in a perspective, partially sectioned illustration,
• 4 shows an anchor carrier with an anchor and a housing part of the relay from FIG. 3,
• 5 and 6 a further embodiment of an anchor carrier with anchor in side view and top view.

1 and 2, the adjustment of a relay according to the invention is shown schematically. In such a relay, two pole plates 6 and 7 are arranged in a plane to one another in a housing, while an armature 8 is also held in the housing parallel to the two pole plates via a resilient support 9. In Fig. 1 the bridge armature 8 is arranged so that it overlaps with the ends of both pole plates 6 and 7 by the same length a, so that - with the same width of the parts, the air gap surfaces between the armature 8 on the one hand and each of the pole plates are of the same size 6 and 7 are formed on the other hand. However, even if the air gap areas are precisely defined, the response values and the dropout values of the relay, i. that is, the voltages are different due to the other manufacturing tolerances. In order to bring these characteristic values into a predetermined narrow range, the armature 8 is displaced in parallel via its support 9 in the housing, so that although the air gap distance to the pole plates is not changed, the overlap regions with respect to the pole plates are increased or reduced. The direction of displacement is indicated in FIG. 2 by the double arrow 15. In the example of Fig. 2, the armature 8 is shifted to the right compared to Fig. 1, so that the overlap length b between the armature 8 and the pole plate 6 has become smaller than the overlap length a of Fig. 1, while the overlap length c between the Armature 8 and the pole plate 7 is greater than the previously existing overlap length a. The response voltage in the arrangement according to FIG. 2 has thus increased, while the dropout voltage has become lower. Instead of the armature, however, the individual pole plates could also be moved separately in order to set the desired values independently.

A relay in which the described adjustment method can be used is shown in FIGS. 3 and 4 described below. The relay shown in FIG. 3 shows a two-part base body, the lower part 1 and the upper part 2 of which are approximately half-shell-shaped and are joined together in such a way that they result in a coil former on which a winding 3 is applied. The lower base body part 1 has a trough-shaped recess 4, the upper base body part 2 has a corresponding trough-shaped recess 5, which together form the contact space. In the upper base part 2, two pole plates 6 and 7 are embedded, in such a way that their free ends extend into the contact space 4, 5 and face each other at a certain distance. The pole plates 6 and 7 can also each be anchored with their longitudinal edges in the side walls of the contact space. A plug-in fastening instead of the embedding would also be possible.

The pole plate 6 has in the flange 2a of the base part 2 a connection element 6a which is integrally formed with its longitudinal extent in the same plane and which is bent outside the base body perpendicularly downward to the connection level of the relay. There it can be designed as a conventional connecting pin or to form a flat contact 6b as shown in FIG. 3 be shaped. The relay is therefore suitable for surface mounting (SM technology). A corresponding connection 7a with a flat contact 7b is formed on the pole plate 7 in the region of the flange 2b. To connect the coil winding 3 are also embedded in the lower housing part 1 in the flanges la and Ib each coil connection pins 3a, which, like the contact connection elements 6a and 7a, can optionally be provided on one or the other side of the relay or on both sides.

An armature 8 is arranged in the contact space 4, 5 and is held parallel to the two pole plates 6 and 7 at a predetermined contact distance and forms an overlap area with each of these pole plates. When the relay is excited, the armature 8 bridges the two pole plates magnetically and electrically. For this purpose, it is provided with a contact layer 8a in the overlapping areas. Corresponding contact layers are also applied to the pole plates. The armature 8 is held by a frame-shaped armature support 9, which will be explained in more detail later with reference to FIG. 4. The connection between anchor 8 and anchor carrier 9 is made by spot welding 10. However, other connection options are also considered.

The design and arrangement of the anchor support 9 in connection with a part of the base body is shown schematically in FIG. 4. The lower base body part 1 has the trough-shaped recess 4 in the central region, which forms the lower part of the contact space. To accommodate the frame-shaped anchor carrier 9, a frame-shaped shoulder 11 is provided in the base body part 1, the height of which corresponds approximately to half the thickness of the anchor carrier 9 made of spring material. A corresponding paragraph is also provided in the upper housing part 2, not shown in FIG. 4, so that when the two housing parts 1 and 2 are joined together, a frame-shaped groove is formed between them, in which the anchor carrier 9 inserted between them is held. A tongue 9 a, which carries the armature 8, is formed on the inside of a cross bar of the frame 9.

As can be seen from Fig. 4, the longitudinal extent of the paragraph 11 in the base parts 1 and 2 is kept longer than the frame of the anchor bracket 9. Thus, the anchor bracket 9 can still be moved within its mounting plane even after joining the housing parts, so that the respective faces of the armature facing the pole plates 6 and 7 can be changed in accordance with FIGS. 1 and 2 in order to adjust the response sensitivity of the relay. In order to be able to move the anchor bracket 9, it has on one side an outwardly projecting adjustment web 12, which can be actuated from the outside in a corresponding recess 13 of the base body 1 or 2. After the relay has been adjusted, the opening 13 can be closed, for example, by pouring in casting compound or adhesive, which at the same time fixes the anchor carrier 9.

A modified embodiment of the anchor carrier is shown in FIGS. 5 and 6 in side view and in plan view. An anchor bracket 19 is shown, which is designed only as a leaf spring clamped on one side. To improve the clamping, the clamped end 19a is widened in a T-shape. It is held in a corresponding groove, not shown, between the two base parts 1 and 2. In this representation, too, the connection point between anchor and anchor carrier is indicated in the form of a weld spot. In this case, the end 19a of the armature carrier 19 serves as an adjustment web which, after the two housing parts have been joined, is still accessible from the outside in order to move the armature in the manner already described and thus to adjust the relay. In order to ensure a defined position of the armature and thus a defined response for the operation of the relay, it is expedient in this embodiment as in the previous one to fix the armature carrier 19 by introducing adhesive or potting compound into the adjustment opening.

The manufacture of the relay is easy because all metal parts are flat stampings that do not need to be bent; the subsequent bending of the connection elements 6a, 7a or 3a on the outside of the base body can be disregarded here. The pole plates 6 and 7 are thus injected as flat stamped parts in the upper housing part 2, while the coil connection elements 3a are injected into the lower housing part 1. After cleaning the trough-shaped recesses 4 and 5 in the two housing parts, these are joined together, the anchor carrier 9 and 19 with the welded-on anchor 8 being arranged between the two housing parts. In this way, he already receives the specified contact distance or air gap distance to the pole plates. After the coil winding 3 has been applied, the armature carrier is moved in the manner described for comparison. This is expediently done in small steps, the response and dropout voltage of the relay being measured in each case by means of a corresponding measuring arrangement. If the values are in the desired range, the relay is adjusted and the anchor bracket can be fixed by gluing the adjustment bar, for example.

A ferromagnetic film 14 is also applied as a flux return via the upper housing part. A final overmolding or dipping process could, if necessary, ensure the fixing of the iron foil and the coil as well as a secure seal of the interior.

In the illustrated and described embodiment of the relay, the armature serves as a bridge contact and therefore does not require its own connection. However, since this type of anchor bracket definitely makes contact with one of the The pole plate closes first and a contact opens in the same way, the relay can also be provided with a lead contact or a follow-up contact. In this case, only the two pole plates 6 and 7 are connected in an electrically conductive manner, for example by welding a contact layer. In addition, in this case the armature requires its own connection element, while one of the connection elements of the pole plates can be omitted. This connection element for the armature can be injected, for example, in the lower housing part 1, an end projecting on the inside being connected to the armature carrier, for example by welding. For this follow-up contact arrangement, contact layers of different properties are then provided in a known manner between armature and pole plates.

Finally, it should also be mentioned that instead of or in addition to the armature, the pole plates can also be arranged displaceably in the housing. For example, it would also be conceivable to embed the armature with its armature carrier in one housing part and to mount the pole plates in a groove formed in the parting plane of the two housing parts and to fix them only afterwards.

Claims (10)

1. Adjustment method for setting the switching characteristics of an electromagnetic relay in which at least one flat pole plate (6, 7) and one armature (8) which is resilient or resiliently mounted and is situated opposite the pole plate with a predetermined air gap with overlapping pole surfaces are arranged in a housing, characterized in that initially only the pole plate (6, 7) or the armature (8) is fixed in the housing, whilst the respective other one of these elements (7, 6, 8) remains arranged displaceably in a guide slot (11) of the housing, maintaining the predetermined air gap but parallel to the pole surfaces,

in that by gradual displacement of the displaceable element (6, 7, 8) the overlapping area of the pole surfaces (a, b, c) is changed and at the same time in each case the characteristic values for the actuation and/or drop-out of the relay are measured and

in that the displaceable element (6, 7, 8) is fixed in the housing when the measured characteristic values lie in a prescribed range.

2. Method according to Claim 1, in which two pole plates (6, 7) are arranged in a common plane opposite to one another with their free ends at a distance and the armature (8) is arranged approximately parallel and opposite the free ends of both pole plates (6, 7), defining in each case one overlapping area (a, b, c), characterized in that either at least one of the pole plates (6, 7) or the armature (8) is arranged to be initially displaceable in the housing (1, 2), and in that at least one of the displaceable elements (8) is displaced and fixed after reaching the desired characteristic values of the relay.

3. Method according to Claim 2, characterized in that the armature (8) is mounted by means of a resilient carrier (9; 19) opposite both pole plates (6, 7) to be displaceable in the guide slot (11) of the housing and is fixed after reaching the desired characteristic values.

4. Method according to Claim 3, characterized in that the armature (8) is displaced in the longitudinal direction of the two pole plates (6, 7).

5. Method according to Claim 3 or 4, characterized in that the armature (8) is displaced transversely to the two pole plates (6, 7).

6. Method according to one of Claims 1 to 5, characterized in that the pole plate or the pole plates (6, 7) are embedded in a first housing part (2), in that the resilient carrier (9, 19) bearing the armature is inserted, when assembling the two housing parts, into a groove (11) formed between the first housing part (2) and a second housing part (1), in that a coil winding (3) is then applied over the assembled housing parts, in that the armature (8) is adjusted in relation to the pole plates (6, 7) by displacing the carrier (9,19) in the groove (11), in each case the actuation or drop-out voltage of the relay being measured, and in that after reaching the desired actuation or drop-out voltage of the armature carriers (9, 19) fixing occurs by pouring in liquid plastic.

7. Adjustable relay according to the method in accordance with one of Claims 1 to 6, having a two-part coil former (1, 2) serving as the housing, a contact space being formed inside the coil former by means of trough-shaped recesses (4, 5) in both coil former parts (1, 2),

having two pole plates (6, 7) opposite to one another embedded in the one coil former part (2) in one plane with their free ends in the contact space (4, 5),

having a flat armature (8) mounted by means of a resilient carrier (9, 19) in the contact space and

having a winding (3) applied over both coil former parts (1, 2), characterized in that both coil former parts (1, 2) are formed from plastic,

in that, in the dividing area between the two coil former parts (1, 2), a groove (11) is hollowed out at least on two opposite sides of the contact space, in which groove the armature carrier (9,19) is arranged at a predetermined distance parallel to the plane of the pole plates (6, 7) but within its main plane with play, and

in that the armature carrier (9,19) is fixed in the groove (11) by additional means.

8. Relay according to Claim 7, characterized in that the armature carrier (19) is shaped like a tongue, is fixed with one end in a groove corresponding to its width and bears the armature (8) with its other end in the contact space.

9. Relay according to Claim 7, characterized in that the armature carrier (9) is in the form of a frame, is arranged in a circumferential groove (11) which extends in at least one direction beyond the length of the armature carrier (9), and in that the armature (8) is secured to a tongue (9a) which extends inwards from one side of the frame.

10. Relay according to one of Claims 7 to 9, characterized in that the armature carrier (9) has an integral adjustment web (12) which extends from the armature carrier (9) towards the outside of the coil former and is accessible from outside at least before the fixing of the armature carrier (9).

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