EP0768694A2 - Electromagnetic relay and method for its manufacture - Google Patents

Abstract

The relay incorporates a coil body (2) with flanges (21,22) and a winding (23), a rod-shaped core (31), an angle yoke (33), with a leg (34) joined to the end (31a) of the core and the other leg (35) parallel to the core next to the winding (23), and a movable armature (4) actuating a contact spring (41). The yoke leg (34) in the flange (21) is secured against axial motion and pivoting by means of holding elements, while the core (31) is joined to the side surface of the yoke leg only by its end face (31). The yoke legs (934) are pushed (drawer fashion) into the grooves of the coil flange (21). The core (31) is joined to the yoke leg by means of hard soldering. Alternatively, it is joined to the yoke leg by means of welding. There are two coil bodies (2) (each with a winding, a core, a yoke and an armature arranged in a mirror-image fashion. The two coil bodies are made as a single component with a central double flange and two end flanges. The coil body is mounted on a base (1) incorporating at least one fixed contact carrier (14,15), and at least one spring carrier (17) for each contact spring (41).

Description

• ein Spulenkörper besitzt einen ersten Flansch und mindestens einen zweiten Flansch, wobei zwischen dem ersten und dem zweiten Flansch Jeweils eine Wicklung angeordnet ist;
• in dem Spulenkörper ist axial zu jeder Wicklung jeweils ein stabförmiger Kern angeordnet;
• ein abgewinkeltes Joch ist jeweils mit einem ersten Jochschenkel in dem Bereich des ersten Spulenflansches an ein erstes Ende des Kerns gekoppelt, während sich ein zweiter Jochschenkel parallel zum Kern neben der Wicklung erstreckt;
• ein beweglicher Anker verbindet unter Bildung eines Arbeitsluftspaltes jeweils den zweiten Jochschenkel mit dem zweiten Ende des Kerns und
• der Anker betätigt mindestens eine Kontaktfeder, die ihrerseits mit mindestens einem Festkontakt zusammenwirkt.

Außerdem betrifft die Erfindung die Herstellung eines derartigen Relais.The invention relates to an electromagnetic relay with the following features:

• a coil former has a first flange and at least one second flange, a winding being arranged in each case between the first and the second flange;
• a rod-shaped core is arranged axially for each winding in the coil former;
• an angled yoke is each coupled to a first end of the core with a first yoke leg in the region of the first coil flange, while a second yoke leg extends parallel to the core next to the winding;
• a movable armature connects the second yoke leg to the second end of the core and to form a working air gap
• the armature actuates at least one contact spring, which in turn interacts with at least one fixed contact.

In addition, the invention relates to the manufacture of such a relay.

Relays with such a general structure are widely known; they can be designed as single or double relays (e.g. DE 42 33 807 A1, DE 38 43 359 C2). The connection between the core and the first yoke leg usually takes place in that the core is inserted into a bore in the yoke leg and then fixed by caulking, welding or in some other way. With these common connection techniques, however, the connection point for the attack of large holding devices and tools must be accessible. This is the case with single relays, but with double relays this has resulted in previous designs two individual magnet systems with coil, core and yoke were manufactured and only subsequently connected to form the double relay. For example, in these cases it was not possible to provide a common coil body for two magnet systems with both windings in one operation and then to mount the iron circuit with yokes and cores in such a double coil.

Another problem for relays of the type mentioned at the outset is that the connection point between the core and the yoke represents a magnetic resistance in the iron circuit, which increases in importance with the increasing miniaturization of the overall system and the associated reduction in the material thicknesses for the yoke and the core. It is important, on the one hand, that the material connection between the core and the yoke is as good as possible and that it is retained over the service life of the relay, so that the connection is not loosened by external forces acting on the yoke. On the other hand, the coupling surface between the core end and an annular recess in the yoke leg becomes increasingly smaller as the material thickness of the yoke decreases. With a sheet thickness of the yoke of less than 1 mm, this coupling surface in a yoke bore represents considerable magnetic resistance even when the two parts are well connected.

The aim of the present invention is therefore to construct a relay of the type mentioned in the introduction and to specify a method for the connection between the core and the yoke, which enables a good mechanical and magnetic coupling between the core and the yoke in a simple manner even with small material thicknesses which can neither be impaired nor destroyed by the action of external mechanical forces on the yoke. This connection between the core and the yoke should be able to be established without particular difficulty both in the case of a single relay and in the case of a double relay, even if the connection point is not accessible from the outside for the attack of larger tools.

According to the invention this goal is achieved in a relay of the type mentioned in that the first yoke leg is secured in the first coil flange by holding elements against movement in the axial direction and against pivoting and that the core butt abuts the side surface of the first yoke leg with its first end and is cohesively connected to it only via its end face.

In the construction according to the invention, the hole in the first yoke leg for receiving the core end is therefore omitted; rather, the end face of this core is butt-welded or soldered to the side surface of the yoke. A larger coupling surface between the core and the yoke is achieved via this end face than via the yoke bore previously customary, since the annular coupling surface in the bore becomes very small with a very low material thickness of the yoke. The additional fixation of the yoke by holding elements of the coil flange also ensures that the welded or soldered connection receives good quality during manufacture and that this quality of the connection is also guaranteed over the lifetime of the relay, since external forces on the yoke are caused by it Fixation in the coil flange are caught, so they can not affect the connection point.

The mounting of the first yoke leg in the coil flange preferably consists in that the first yoke leg with parallel side edges is inserted in a drawer-like manner perpendicular to the coil axis in grooves of the first coil flange. The yoke leg is appropriately caught on three sides in grooves of the coil flange, so that only a movement in the direction of insertion is possible up to the stop.

The connection of core and yoke specified according to the invention is fundamentally also advantageous in the case of individual relays, in particular when using very thin yoke plates, for example with a thickness of less than 1 mm. However, there is a particular advantage when two bobbins, each with a winding, a core, a yoke and an armature, are constructed and connected to each other in such a mirror image that the coil axes are aligned and the first two yoke legs are parallel - while maintaining an insulating distance . In this case, it is particularly advantageously possible to form the two bobbins by means of a one-piece double bobbin, a common first flange as the central flange carrying the two first yoke legs and the two second flanges as end flanges on opposite sides of the relay. Since the first two yoke legs of such a double relay with the corresponding core ends are not accessible for another joining method, in this case the type of connection according to the invention only enables such a relay structure in which both windings can be applied to a common coil former beforehand and the two Cores are subsequently inserted into the double bobbin from two opposite sides. It is also possible to use cores with enlarged pole plates, since the cores are inserted into the respective bobbin from the armature side.

• a) das Joch wird jeweils mit seinem ersten Jochschenkel senkrecht zur Spulenachse in Nuten des ersten Spulenflansches eingesteckt;
• b) der jeweilige Kern wird in Axialrichtung in den Spulenkörper eingesteckt, bis sein erstes Ende mit der Stirnfläche an die Seitenoberfläche des ersten Jochschenkels anstößt; und
• c) durch Anlegen einer Spannung zwischen dem Joch und dem Kern werden die beiden Elemente an ihrer Stoßstelle durch Widerstandserwärmung stoffschlüssig verbunden.

A method for producing a relay according to the invention essentially comprises the following steps:

• a) the yoke is inserted with its first yoke leg perpendicular to the coil axis in grooves of the first coil flange;
• b) the respective core is inserted into the coil body in the axial direction until its first end abuts the side surface of the first yoke leg with its end face; and
• c) by applying a voltage between the yoke and the core, the two elements are integrally connected at their joint by resistance heating.

This method can also be used analogously for the double relay mentioned, in which case the two first yoke legs are inserted in parallel into corresponding grooves in the central flange and these two first yoke legs are preferably connected to a first welding potential by an interposed contact plate, while the two cores are parallel can be connected to a second welding potential. In this way, the two core-yoke connections can be made simultaneously. The welding current is expediently dimensioned such that a type of brazing occurs between the respective core and the respective yoke, a surface coating of the parts with copper, silver or another brazing material forming the connection. There is essentially no additional effort, since the iron parts are normally coated with copper or the like as corrosion protection anyway. All metals that alloy with iron and have a lower melting point than iron can be used, for example around 1000 ° C or lower. The layer thickness of the brazing material on the surface of the core or yoke is usually between 4 and 6 µm. The contacting plate mentioned does not weld to the two yoke legs, since it forms a very large contact area with them; after welding or brazing, it can easily be pulled out of the central flange.

Finally, it should also be mentioned that the arrangement of the two switching systems with cores aligned with one another and closely arranged first yoke legs, which is made possible by the type of core-yoke connection according to the invention, also results in a close magnetic coupling of the two switching systems. This magnetic coupling can also be used of the double relay can be used. If, for example, the two excitation coils are wound and excited so that the magnetic fluxes through both cores are in series, the excitation of one magnet system also supports the response of the other, so that the overall reliability of the double relay is improved. In certain cases the mutual influence can also be exploited by correspondingly opposite excitation.

Figur 1

ein erfindungsgemäß gestaltetes Doppelrelais in perspektivischer Darstellung (ohne Kappe),

Figur 2

die Einzelteile des Relais von Figur 1 in Explosionsdarstellung,

Figur 3

einen Längsschnitt durch die Kerne und Joche des Doppelrelais gemäß Figur 1 oder 2 mit einer schematisch gezeigten Schweißanordnung,

Figur 4

einen Schnitt durch das Relais von Figur 1 entlang seiner Spiegelebene,

Figur 5

einen senkrechten Schnitt durch das Relais von Figur 1 und

Figur 6

einen waagerechten Schnitt durch das Relais von Figur 1.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. It shows:

Figure 1

a double relay designed according to the invention in a perspective view (without cap),

Figure 2

the individual parts of the relay of Figure 1 in an exploded view,

Figure 3

2 shows a longitudinal section through the cores and yokes of the double relay according to FIG. 1 or 2 with a schematically shown welding arrangement,

Figure 4

2 shows a section through the relay of FIG. 1 along its mirror plane,

Figure 5

a vertical section through the relay of Figure 1 and

Figure 6

a horizontal section through the relay of Figure 1.

The relay shown in FIGS. 1 and 2 has a base 1 on which two switching systems A and B are arranged mirror-symmetrically to a plane of symmetry defined by the coordinates x and z in FIG. Since in the two switching systems A and B all parts are either arranged mirror-symmetrically or mirror-symmetrically designed and the have the same function, the same reference numerals are used for both switching systems.

The base 1 is essentially designed as a flat plate which defines a bottom side 11; on this an extension 12 is formed vertically upwards, which is designed like a labyrinth to form plug channels 13 for two pairs of fixed contact carriers 14 and 15 and plug channels 16 for two spring carriers 17. The fixed contact carrier and the spring carrier each emerge with connecting pins to the underside of the base 1. The fixed contact carrier 14 carries a normally closed contact 14a, while the fixed contact carrier 15 is provided with a normally open contact 15a. Each of the two spring supports 17 has a soldering tab 17a bent to the side.

A double bobbin 2 is arranged on the base. It has a central flange 21 and two end flanges 22 lying in the plane of symmetry between the two switching systems, a winding 23 being arranged in each case between the central flange and each of the end flanges. Each of the end flanges 22 has on the side facing away from the spring supports 14 and 15 a flange shoulder 24 with two coil connecting pins anchored therein. Within each winding 23, a core 31 with a pole plate 32 is inserted from the outside into the coil body, so that the Pole plate 32 is partially in a recess of the end flange 22; towards the flange extension 24, the pole plate is cut on one side. Furthermore, each switching system has an angled yoke 33 with a first yoke leg 34 and a second yoke leg 35, both of which are perpendicular to one another and perpendicular to the bottom side 11. The first two yoke legs 34 are inserted parallel to one another into a lateral opening 26 in the central flange 21 (see also FIG. 6). This opening 26 in the central web has a circumferential central web 27, whereby for each of the yoke legs 34 a peripheral groove 28 is formed on three sides, into which the respective yoke leg 34 is inserted like a drawer.

At the same time, the thickness of the web 27 ensures the insulating distance between the two yoke legs 34.

An approximately plate-shaped anchor 4 is also perpendicular to the bottom side 11 with its main plane; in the present example it is slightly cranked only in adaptation to the shape of the bobbin. The armature 4 is mounted on the free end edge 35a of the second yoke leg 35 without being connected to the yoke via a bearing spring or the like. Rather, the armature is mounted and held via a contact spring 41, which rests laterally with an end section 41a on the armature and is connected to the armature via one or two rivets 42. Starting from the end section 41a, the contact spring 41 is fork-shaped in the direction of the free armature end and thus forms a contact leg 43 with a movable center contact 43a and a connecting leg 44. All sections of the cranked and bent contact spring 41 are perpendicular to the bottom side 11, so that the contact leg 43 is substantially above the connecting leg 44. On the connecting leg 44, a fastening section 45 is bent approximately perpendicularly and carries at its free end a spring tab 46 bent inward in the shape of a hook. The fastening section 45 is inserted between a vertical insulating wall 18 of the base attachment 12 on the one hand and the soldering tab 17a of the spring support 17 and clamped to the attachment 12 of the base 1 with the spring tab 46. In addition, the soldering tab 17a is conductively connected to the fastening section 45, preferably soldered or welded.

The function of the two switching systems of the double relay can easily be seen. When the respective coil 23 is excited, the associated armature 4 is attracted to the associated pole plate 32, wherein it switches the movable center contact 43a from the break contact 14a to the make contact 15a via the contact leg 43. Both switching systems can be operated individually or together. Of course it is also possible Both switching systems can be used together as reversing polarity relays. In this case, the two spring carriers 17, as shown in FIG. 2, could remain connected and the normally closed contact carriers 14 and the two normally open contact carriers 15 could each be externally connected to one another.

In the manufacture of the relay described, the base 1 is first equipped with the contact carriers. The fixed contact carrier 14 and 15 for both switching systems can be cut free in pairs from a band and bent into their final shape. Preferably, both pairs of fixed contact carriers 14 and 15 are inserted into the base at the same time and only then separated. The two spring supports 17 for both switching systems are preferably inserted in the base 1 in a coherent manner and only then separated from one another at the separation point 143.

When assembling the two cores, as shown in FIG. 3, they are inserted into the coil body 2 so that the respective core rests with its inner end face 31a on the flat side of the yoke leg 34. A welding current is then passed over the respective yoke 33 and the respective core 31, which causes the two parts to be welded or brazed at the point of contact by resistance heating. In this brazing process, the copper coating of the core and / or yoke, which is already present as a surface treatment, serves as a braze. In this way, there is an almost gap-free connection between the core and the yoke, as a result of which the magnetic resistance is minimized. The intended butt welding of the core to the yoke leg 34 is particularly advantageous if the yoke consists of a thin and space-saving sheet, for example with a thickness of <1 mm. The effective magnetic saturation values for thin sheets also have a positive effect on the magnetic circuit.

This type of butt welding or soldering of the core can be carried out in the relay according to the invention because the first yoke leg 34 is guided in the grooves 28 of the central flange 21 and is kept stable. Since the core 31 itself is also held in the coil body, the connection point 36 (see FIGS. 5 and 6) is not loaded by any leverage forces, so that the butted solder connection is not endangered. Otherwise, the two core-yoke connections can be made simultaneously. For this purpose, a contact plate 37 is inserted into the insulating gap between the two first yoke legs 34, which is connected to one pole of the welding current source. If the two cores are then connected in parallel to the other pole of the welding current source via electrodes 38, the two connection points 36 can be welded or brazed simultaneously. The contact plate 37 is then pulled out of the coil former. The coil former 2, which is equipped with the cores and yokes, is positioned on the base, with cold lugs 29 latching onto the central flange 21 and onto the flange extensions 29 in correspondingly undercut recesses 19 in the base.

The two anchors 4 with the mirror-symmetrically bent contact springs 41 are inserted into the base after the coil former, the fastening section 45 of the respective contact spring being inserted between the insulating wall 18 and the soldering tab 17a and clamped onto the shoulder 12 of the base by means of the spring tab 46. The soldering tab 17a is preferably provided with a tin coating 17b on the side facing the fastening section 45, so that it can be soldered to the fastening section 45 of the contact spring 41 with the aid of a heat source. This is done, for example, using a TIG arc. A soldered or welded connection using a laser or another heat source would also be possible.

Since the free ends of the fixed contact carriers 14 and 15 with the fixed contacts 14a and 15a protrude beyond the connecting leg 44 or the fastening section 45 of the contact spring, they are easily accessible for any necessary bending adjustment.

As already mentioned at the beginning, the construction according to the invention can be implemented not only as a double relay, but also as a single relay. For this purpose, only the described construction of the double relay along the mirror plane, as indicated in FIG. 1, needs to be halved. Such a section is shown in FIG. 4. To complete the individual relay thus created, it is only necessary to adapt the halved base and the halved coil body on the cut side, so that the closed individual relay is produced with a housing cap which is also half the size. The remaining parts can also be used unchanged for the individual relay, so that a separate description is unnecessary.

Claims (11)

Electromagnetic relay with the following features: - a coil former (2) has a first flange (21) and at least one second flange (22), a winding (23) being arranged between the first and the second flange; - A rod-shaped core (31) is arranged axially for each winding (23) in the coil former (2); - An angled yoke (33) is each coupled to a first yoke leg (34) in the region of the first coil flange at a first end (31a) of the core, while a second yoke leg (35) is parallel to the core next to the winding (23) extends; - A movable armature (4) connects the second yoke leg (35) with the second end (32) of the core (31) and to form a working air gap the armature (4) actuates at least one contact spring (41) which in turn interacts with at least one fixed contact (14a, 15a), characterized in that the first yoke leg (34) in the first coil flange (21) is secured by holding elements (27) against movement in the axial direction and against pivoting, and in that the core (31) with its first end (31a) is blunt on the side surface of the the first yoke leg (34) and is integrally connected to it only via its end face (31a). Relay according to Claim 1, characterized in that the first yoke leg (34) with parallel side edges is inserted in a drawer-like manner perpendicular to the coil axis in grooves (28) of the first coil flange (21). Relay according to Claim 1 or 2, characterized in that the core (31) is brazed to the first yoke leg (34). Relay according to Claim 1 or 2, characterized in that the core (31) is welded to the first yoke leg (34). Relay according to one of Claims 1 to 4, characterized in that two coil formers, each with a winding (23), a core (31), a yoke (33) and an armature (4), are constructed in mirror image and connected to one another in such a way that the Align the coil axes with each other and the first two yoke legs (34) lie parallel to each other - while maintaining an insulation distance. Relay according to Claim 5, characterized in that the two coil formers are formed by a one-piece double coil form (2), a common first flange (21) carrying the two first yoke legs (34) as the central flange and the two second flanges (22) as End flanges sit on opposite sides of the relay. Relay according to Claim 5 or 6, characterized in that the first two yoke legs (34) are fastened in parallel grooves (28) in the central flange (21) which are separated from one another by a circumferential web. Relay according to one of Claims 1 to 7, characterized in that the respective coil former (2) is fastened on a base (1) in which at least one fixed contact carrier (14, 15) and at least one spring carrier (17) for each contact spring (41 ) are anchored. Method for producing a relay according to one of Claims 1 to 8, comprising the following steps: a) the yoke (33) is inserted with its first yoke leg (34) perpendicular to the coil axis in grooves (28) of the first coil flange (21); b) the respective core (31) is inserted in the axial direction into the coil former (2) until its first end (31a) abuts the side surface of the first yoke leg (34) with the end face; and c) by applying a voltage between the yoke (33) and the core (31), the two elements at their joint (36) are integrally connected by resistance heating. Method according to Claim 9, characterized in that when two yokes (33) and two cores (31) are arranged in a mirror image in a double coil former (2), the two first yoke legs (34) are parallel and at a distance into corresponding grooves (28) in the central flange (21) are inserted so that the two cores (31) are inserted into the coil body (2) from opposite sides, that the two first yoke legs (34) are then connected to a first potential via an interposed contact plate (37) and the two cores (31) Electrodes (38) are connected in parallel to a second potential. Method according to Claim 9 or 10, characterized in that, by appropriate dimensioning of the current flow via the joints (36) of the core and yoke, hard soldering is produced, a surface coating of the core (31) and / or of the yoke (33) with a Material used at a correspondingly low melting temperature as a braze.

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