EP0072975A1 - Electromagnetic relay - Google Patents

Abstract

The relay has a rod-shaped armature (21), which is supported at one end via an insulating material carrier (34) on a coil flange (20). At the side of the armature, center contact springs (39) are anchored in the support (34), to which the armature movement is transmitted via the support (34). This eliminates a slide for contact actuation. The staggered arrangement of the center contact springs (39) in the carrier (34) creates friction at the contact points, which largely prevents contact bruises.

Description

The invention relates to an electromagnetic relay with an excitation coil and an elongated, one-sided armature, which extends substantially parallel to the coil axis and to which at least one contact spring is insulated on one side, which extends parallel to the armature and with its free end in each case 'interacts with at least one counter-contact element.

Such a relay is known for example from FR-PS 20 48 396. There, several center contact springs arranged in one plane are clamped to a plate-shaped armature via a resilient retaining clip, these "contact springs being electrically insulated from the armature only by an interposed film. The contact springs simultaneously form the bearing for the armature, which with its flat side opposite the springs, when the relay is energized, bridges two spaced-apart yoke core parts. The direct connection of the contact springs to the armature saves a separate actuating slide, and there is no abrasion of such a slide which is harmful to the contacts.

However, the arrangement in the known relay is disadvantageous in that not only the armature and a core, but also all the center contact springs are arranged and take up space within the coil body, so that the coil has a relatively large diameter. The arrangement of the anchor with the fixed ver tied center contact springs in the vicinity of the counter contacts also results in a short spring length and high stress on the spring material. Furthermore, the arrangement of the contact springs directly on one side of the flat armature has the disadvantage that the armature can only form a working air gap on one flat side opposite the springs, so that, for example, a polarized system in which the armature forms working air gaps with two opposite pole plates cannot be used.

The object of the invention is to provide a relay of the type mentioned with high contact reliability, in which the connection of the contact springs to the armature is designed so that on the one hand good contact is guaranteed with low stress on the spring material and on the other hand the armature essentially Can switch freely over its entire length in any magnet system, with effective polarized magnet systems in particular also being able to be used. '

According to the invention, this object is achieved in that the rod-shaped armature is fastened at one end in an insulating support and is mounted on a first coil flange via this support, and also extends essentially over the entire coil length to the opposite second coil flange, where it has at least one Polblech forms a working air gap, and that the contact springs also anchored in the carrier extend outside the coil at a distance from the armature also substantially over the entire coil length.

The insulating support provided according to the invention thus serves to anchor the armature and the movable contact springs keep a distance from each other and store together on the coil flange. Both the armature and the movable contact springs extend parallel to the coil axis to the opposite coil flange, whereby the mutual distance ensures that the magnet system on the one hand and the contact units on the other hand do not interfere with each other. The bearing point is so far from the contact points that practically no abrasion can reach the contact surfaces. In addition, the bearing friction is very low, since the armature stroke causes only a small swiveling movement in the bearing due to the elongated design of the armature and the parallel contact springs. The armature itself can expediently be arranged inside the coil body along the coil axis, while the contact springs connected to the armature are in any case outside the coil body. This allows, for example, a very sensitive polarized magnet system to be used. Since the armature lies alone in the coil body without additional parts, it takes up little space, so that a coil with a small diameter can be used.

Another advantage of the construction according to the invention is that the spring material of the movable contact springs fastened in the carrier is only slightly stressed. is, because with the large clamping length the deflections are small and therefore relatively thick contact springs can be used. In addition, the relay makes optimum use of the excitation energy, since the energy introduced into the springs is fully converted into contact force without an intermediate actuating slide. The long contact springs freely arranged next to the coil finally have the advantage that they are easily accessible for adjustment, so that the desired high contact reliability is also achieved in this way is guaranteed. Here, in particular, contact-free adjustment methods can be used, the method with dosed heat application described in DE-OS 29 18 100 being particularly important.

In one embodiment of the invention, the movable contact springs could be fastened in the carrier in an extension of the bearing axis of the armature. You would then align with the anchor and immediately participate in its switching movement. However, an arrangement is more advantageous in which the movable contact springs are anchored in the carrier parallel to the anchor, but offset relative to the bearing point. As a result of this offset arrangement with respect to the bearing point, its center of movement deviates from its clamping point, so that they perform a frictional movement on their mating contact elements when switching. This reduces the contact bruises and the failure rates of the contacts.

At least one movable contact spring is expediently arranged symmetrically on both sides of the armature. However, it is also possible for two movable contact springs to be fastened one above the other in the carrier, in alignment with one another. In this way, four or more changeover contacts can be constructed.

The carrier is expediently T-shaped, one or more contact springs being anchored in the middle part of the armature and in the two side arms. The contact springs can be fastened with a straight fastening end in the carrier. This attachment can be done in the usual way either by inserting or by embedding, such as injection. In a particularly advantageous embodiment, the contact springs are angled det, where they emerge from the carrier with their fastening end perpendicular to the bearing axis and are angled and bent in such a way that their contacting legs run parallel to the anchor.

In a further advantageous embodiment it is provided that the contact springs anchored in the carrier each have a first section with a first spring thickness starting from their clamping point and a second section with a second spring thickness in the region of their contacting ends, the second spring thickness being at least half is smaller than the first spring thickness. The contact springs thus have a stepped cross section, the thin end section having high elasticity due to the small spring thickness and ensuring good contact with the respective counter contacts. This thin end section is expediently slit lengthwise to achieve double contact. The thicker first section of the contact springs, on the other hand, ensures the necessary spring rate. In addition, this thicker, unslotted area is well suited for adjusting the contact springs. In the aforementioned adjustment method with metered application of heat, for example by means of laser beams, the contact springs can be adjusted in this way without the heat rays heating the contact springs in their entire thickness and thereby changing their spring characteristics. This risk would exist with continuously thin contact springs. The first, thicker section is expediently at least half the free spring length of the respective contact spring. The spring thickness in the first section is expediently about three times as large as that of the second section.

The carrier is expediently formed by means of Bearing journal stored in recesses in the coil flange. In another expedient embodiment, it could also have bearing cutting edges which are mounted in corresponding notches in the coil flange. The carrier can be pressed into the bearing of the coil flange by a spring. This spring can consist of ferromagnetic or non-magnetic metal, but a plastic film can also be used as the spring. However, the armature can also be held in the bearing by a back plate of the magnetic circuit, a spring or a film being optionally arranged between the back plate and the carrier.

An embodiment is particularly expedient in which bearing pins formed on the armature can be snapped into slotted bearing bushes of the coil former. These bearing bushes expediently have a diameter which corresponds at least to the diameter of the bearing pins. This results in a low bearing friction; Even a slight play of the bearing journals in the bushes has an imperceptible effect on the switching movements at the other armature end or at the contacting ends of the contact springs.

• Fig. 1 eine Prinzipdarstellung eines Relaisankers mit erfindungsgemäß ohne Schieber betätigbarer Kontaktfeder,
• Fig. 2 bis 6 ein erfindungsgemäß aufgebautes Relais in verschiedenen Ansichten,
• Fig. 7 eine perspektivische Darstellung des in den vorangehenden Figuren dargestellten Ankers mit Träger und Kontaktfedern,
• Fig. 8 eine abgewandelte Ausführungsform eines Trägers mit Anker und Kontaktfedern,
• Fig. 9 eine abgewandelte Ausführung eines Relais gemäß Fig. 3,
• Fig.10 eine weitere Ausführungsform eines Trägers mit Anker und Kontaktfedern.

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

• 1 shows a schematic diagram of a relay armature with a contact spring which can be actuated according to the invention without a slide,
• 2 to 6 a relay constructed according to the invention in different views,
• 7 is a perspective view of the armature shown in the previous figures with carrier and contact springs,
• 8 shows a modified embodiment of a carrier with armature and contact springs,
• 9 shows a modified embodiment of a relay according to FIG. 3,
• 10 shows a further embodiment of a carrier with an anchor and contact springs.

Fig. 1 shows a rod-shaped relay armature 1, which extends within a coil winding 2 along its axis and is fixed at one end 1a in a carrier 3 made of insulating material and is mounted on this carrier with a pin 4. With its free end 1b, the armature carries out switching movements between two pole plates 5 and 6.

Parallel to the armature, a contact spring 7 is also anchored in the carrier 3, which extends next to the coil over its entire length and can be switched over with its free end between two mating contacts 8 and 9. By the distance a between the bearing axis on the pin 4 and the clamping point 10 of the contact spring 7, the contacting end 7a of the contact spring 7 is moved in a circle around the bearing pin 4, so that it carries out a frictional movement on the counter contacts 8 and 9, respectively. This largely suppresses contact bruises. Of course, the carrier can be designed symmetrically to the bearing axis and accommodate a contact spring 7 on each side of the armature.

The relay shown in FIGS. 2 to 6 has a polarized magnet system and two changeover contacts, although other magnet systems and contact assemblies would also be possible. The relay is built on a base body 11 and closed with an insulating protective cap 12. The edge joint 13 between the base body and the cap is sealed with casting resin 14, the bushings of coil connecting pins 15 also being sealed. On the base body 11 sits in a precisely fitting recess 16 (FIG. 4), a coil body 17 with the winding 18, which is delimited on the end face by the two coil flanges 19 and 20. Within the coil body, a rod-shaped armature 21 extends along the coil axis, which is supported by its end 21b on the coil flange 20 and with its free end 21a can perform switching movements between two pole plates 22 and 23.

In order to determine the width of the working air gap 24 between the two pole plates 22 and 23, contact surfaces 25 and 26 are provided on the coil former 17, against which the pole shoes 22 and 23 are pressed by lugs 27 and 28 formed on the coil flanges. The pole plates 22 and 23 are each part of the two yokes 29 and 30, which extend above the coil parallel to the coil axis and to the base body 11. On these yokes 29 and 30 there is a flat and also elongated permanent magnet 31 with two oppositely polarized permanent magnet regions 31a and 31b. The pole faces of the four-pole permanent magnet 31 opposite the yokes are covered by a flux plate 32, which closes both the permanent flux circuit and the excitation flux circuit.

The armature 21 is fastened in a carrier 34 made of insulating material. For this purpose, the carrier 34 has an opening 34a in which the armature is fastened by insertion (FIG. 5). A rib 34b formed in the wall of the opening compensates for the greater cutting tolerance in the armature 21 and also ensures that the armature 21 is firmly seated in this plane. The carrier 34 has molded journals 35 on the top and on the underside, which sit in bearing bushes 36. These bearing bushes 36 are each formed by two resilient holding arms 37 which are formed on the coil flange 20. FIG. 6 shows in a section VI-VI from FIG. 5 a view of the lower bearing bush 36 before the armature is installed. When mounting the armature, the journals are thus latched between the two resilient holding arms 37. In order to cause as little bearing friction as possible, the diameter of the bearing bush 36 is at least as large as the diameter measured the diameter of the bearing pin 35. The parts are manufactured in such a way that, due to the tolerances, there is at least some play between the bearing journal 35 and the bearing bushes 36. In this case, the armature has a small amount of play in the bearing, but this has practically no effect on the switching function due to the long armature.

The carrier 34 is T-shaped and carries in its two side legs 34c and 34d (see FIG. 5) each a center contact spring 39, which are firmly connected to the armature in this way and participate in the switching movements without the need for a separate contact slide . The free end 39a of this center contact spring alternately makes contact with one of the mating contact elements 40 or 41, which are provided in the usual way with contact pieces or contact surfaces. The center contact springs 39 are each connected to a connecting pin 43 via a strand 42. The mating contact elements 40 and 41 are each anchored directly in the base body 11. The central bicontact springs 39 are each embedded with their fastening ends 39b in a side leg 34c or 34d of the carrier 34. They emerge laterally opposite one another from the carrier 34 and are then bent and angled so that their free ends 39a extend parallel to the anchor.

When assembling the magnet system, the two yokes 29 and 30 are pushed onto the coil former 17 in such a way that the pole plates 22 and 23 are positioned between the contact surfaces 25 and 26 on the one hand and the lugs 27 and 28 on the other hand. The yokes. 29 and 30 rest on shoulders 44 and 45 of the coil flanges 19 and 20, respectively. They are fixed together with the permanent magnet 31 and the flux plate 32 by two pins 46 and 47, which are molded onto the thermoplastic coil body 17. These pins 46 and 47 are inserted through recesses 48 and 49 of the flow plate 31 and deformed over the flow plate to rivet heads 46a and 47a.

Due to the dimensionally accurate mounting of the pole plates, the armature in its two end positions also has a defined distance from the mating contact elements 40 and 41 on both sides of the coil body. Since the mating contacts 40 and 41 can be aligned very precisely to one another in the inserted or injected state, only the center contact springs 39 need to be adjusted during assembly, which in turn are firmly connected to the armature 21, so that no additional tolerances due to a contact slide or the like occur. The center contact adjustment is a path adjustment and can be easily automated.

In order to insulate the center contact springs 39 and their connecting strands 42 well from the coil winding 18, additional insulating ribs 50 and 51 are arranged on both sides of the coil on the base body 11.

Fig. 7 shows a perspective view again of the carrier 34 with the inserted armature 21 and the two center contact springs 39. The distance that these center contact springs 39 have from the armature bearing (journal 35) results in each case on the contact pieces 39c a frictional movement with respect to the mating contacts 40 and 41. In a modification not shown, intermediate parts could also be embedded in the carrier 34, to which the contact springs 39 are riveted or welded outside the carrier.

Fig. 8 also shows a perspective view of a modification compared to Fig. 7. The carrier 54 carries the anchor 21 as before and is mounted with a pin 55.

However, this support 54 has in its side part 54a two superimposed center contact springs 56 and 57, so that two superimposed changeover contacts are created with corresponding mating contact elements. This arrangement could also be expanded in a manner not shown in such a way that the carrier 54 also contains a side part 54a symmetrically on the other side of the armature, with contact springs 56 and 57 also lying one above the other.

Fig. 9 shows further modifications compared to the previously shown relay. A view from above of the coil is shown, similar to FIG. 3. In modification of FIG. 3, the armature 21 here has a carrier 58 with longer side arms 59, in each of which contact intermediate pieces 60 are embedded. Center contact springs 61 are welded to each of these contact spacers, and are also. they are connected via connection springs 62 to connection pins 63 in the base body 11.

A further modification in the representation according to FIG. 9 consists in the mounting of the armature or the carrier 58. In this case, this carrier 58 has molded-on bearing cutting edges 64 which engage in corresponding bearing notches 65 of the coil former 66. The carrier is pressed into these bearing notches 65 via a film 67. The film itself is held by a bent sheet metal bracket 68, which can be part of the flow sheet 32 (FIG. 2).

Further modifications and combinations of the illustrated exemplary embodiments are possible. Thus, instead of the bearing cutting edges 64, bearing journals could also be provided, which on corresponding recesses in the coil former. abut the front and are held in these recesses by a spring or by a film.

Fig. 10 shows a perspective view of a modified embodiment of the carrier with armature and contact springs. The armature 71 together with the two contact springs 72 and 73 is anchored in parallel in a support 74, for example by embedding or also by insertion. This carrier 74 is constructed and stored in a similar manner to that in the previously described exemplary embodiments. The contact springs, however, have a stepped cross section, in a modification of the previous exemplary embodiments. In the area of clamping up to approximately half of their free length, these contact springs 72 and 73 each have a first section 72a and 73a with a thicker cross section, while at their free end they each have a thinner section 72b and 73b. These thinner sections 72b and 73b are each slotted so that each contact spring forms a double contact with its fork-shaped ends with the contact surfaces 72c and 72d or 73c and 73d.

The thickness of the spring in the first section 72a or 73a in the exemplary embodiment is approximately 0.5 mm, while the thickness in section 72b or 73b is approximately 0.17 mm. As a result, the thin section 72b or 73b with the longitudinal slot 75 or 76 in each case results in a high degree of elasticity and thus a high level of contact security, the slot 75 or 76 ensuring decoupling of the contacting end surfaces 72c and 72d or 73c and 73d .

The thicker sections 72a and 73a each provide the necessary spring rate for the overall spring, and these unslit sections are also well suited for adjusting the contact springs. In this case, in particular contactlessly acting adjustment means can be used, such as the use of Exposure to heat, such as laser beams. In this way, a very precise adjustment of the relay can be carried out, which in turn contributes to the contact reliability. The contact springs 72 and 73 can most conveniently be cut from a sheet metal strip with a graduated cross section.

Claims (20)

1. Electromagnetic relay with an excitation coil and an elongated, one-sided.Anchor that extends essentially parallel to the coil axis and to which at least one contact spring is insulated, which extends parallel to the armature and with its free end each with at least one mating contact element cooperates, characterized in that the rod-shaped armature (21) is supported at one end via an insulating support (34) on a first coil flange (20) and extends essentially over the entire coil length to the second coil flange (19), whereby it forms a working air gap in the area of this second coil flange with at least one pole plate, and that the contact springs (39) anchored in the carrier (34) extend outside the coil (18) at a distance from the armature (21), likewise essentially over the entire coil length . 2. Relay according to claim 1, characterized in that the armature (21) in the coil body (17) is arranged along the coil axis. 3. Relay according to claim 1 or 2, characterized in that the contact springs are anchored in alignment with the armature in extension of the bearing axis in the carrier. 4. Relay according to claim 1 or 2, characterized in that the contact springs (39) are anchored parallel to the armature (21) by a predetermined distance (a) relative to the bearing axis in the carrier (34). 5. Relay according to one of claims 1 to 4, characterized in that at least two contact springs (56, 57) are anchored in alignment with one another in the support (54). 6. Relay according to one of claims 1 to 5, characterized in that contact springs (39) are arranged on both sides of the armature (21). 7. Relay according to one of claims 1 to 6, characterized in that the carrier (34) is T-shaped, wherein in the middle part of the armature (21) and in the two side arms (34c, 34d) in each case at least one contact spring (39 ) are anchored. 8. Relay according to claim 7, characterized in that the contact springs (39) emerge perpendicular to the bearing axis from the carrier (34), the contact legs (39a) extending parallel to the armature (21) by bending and bending. 9. Relay according to one of claims 1 to 7, characterized in that in the carrier (74) anchored contact springs (72, 73) starting from their clamping point each have a first section (72a, 73a) with a first spring thickness and in the region of their contacting ends each have a second section (72b, 73b) with a second spring thickness, the second spring thickness being at least half less than the first spring thickness. 10. Relay according to claim 9, characterized in that the first section (72a, 73a) of the contact springs (72, 73) takes up about half of their respective free spring length. 11. Relay according to claim 9 or 10, characterized in that the contact springs (72, 73) in the area of their respective second section (72b, 73b) are slotted lengthways (75, 76). 12. Relay according to one of claims 9 to 11, characterized in that the first spring thickness is approximately three times as large as the second spring thickness. 13. Relay according to one of claims 1 to 12, characterized in that the carrier (34) by means of molded bearing pins (35) in recesses (36) of the coil flange (20) is mounted. .14. Relay according to one of claims 1 to 12, characterized in that the carrier (58) by means of molded. Bearing cutting (64) in notches (65) of the coil flange (66) is mounted. 15. Relay according to one of claims 1 to 14, characterized in that the carrier is pressed by a spring (67) into the bearing of the coil flange (66). '16. Relay according to claim 15, characterized in that the spring consists of metal. 17. Relay according to claim 15, characterized in that a plastic film (67) is used as the spring. 18. Relay according to one of claims 1 to 13, characterized in that the armature (21) through a return plate (68) of the magnet Circle is held in the storage, a spring (67) between the return plate (68) and the carrier (58) is optionally arranged. 19. Relay according to one of claims 1 to 14, characterized in that the armature (21) is held non-positively in the carrier (34) by plug-in fastening. 20. Relay according to claim 13, characterized in that the bearing pins (35) in slotted bearing bushes (36) of the coil body (17) can be latched.

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