EP0308819B1 - Electromagnetic relay - Google Patents

Description

The invention relates to an electromagnetic relay with a base body that has at least one flat bottom side, a coil arranged on the base body with its axis parallel to the bottom side, an angled core with at least two mutually perpendicular legs, all in a common plane parallel to the bottom side lie, and with an also lying in the plane parallel to the bottom armature, which is pivotally mounted on the free end of one of the core legs and forms a working air gap with the free end of another core leg, and with a contact arrangement which has at least one movable contact spring and at least has a fixed mating contact element, each of which is firmly clamped with an end section and connected to a connecting element anchored in the base body. In particular, the invention relates to a miniaturized relay which is capable of switching even higher voltages, in particular mains voltage.

Various relays of this type are already known for switching high voltages, which usually have a coil with core and armature and a contact arrangement actuated by the armature. Normally, in these relays, the contact springs are actuated by the armature directly or via a slide which actuates the respective contact spring in a direction essentially perpendicular to its longitudinal extent. Since these contact springs are operated in the vicinity of their contact point, it follows that the switching stroke of the switching contact element can not be greater than the armature stroke, so that the armature stroke determines the contact distance achievable with such a relay. If the magnet system of the relay is reduced, the effective lever arm of the armature is also shortened and the available contact distance is reduced in the same way. However, a certain minimum contact distance is required for high-voltage relays, so that further miniaturization of such relays is not possible.

EP-A-0 202 651 describes a mains voltage relay which essentially corresponds to the design mentioned at the beginning. However, the armature is arranged there within the coil, while the magnetic circuit outside the coil is closed via a yoke. However, the contact spring is actuated in the above-mentioned manner in a direction transverse to its longitudinal extent, so that the contact stroke cannot be significantly greater than the armature stroke.

A relay of the type mentioned is also known from EP-A-63 487. There, the movable contact spring is fastened with an end section in a slot of a base body attachment. The actuation of the contact spring also takes place transversely to the longitudinal extent of the spring, at its free end, so that the contact stroke of the contact piece closer to the clamping point is smaller than the stroke of the actuating slide.

The object of the invention is to provide a miniaturized relay of the type mentioned for switching high voltages, in which despite the miniaturization, a large contact distance can be achieved even with a relatively small armature stroke. In addition, the relay should be simple and easy to manufacture and assemble.

With regard to the use in high-voltage circuits, the dielectric strength between the contact arrangement and the coil should also be ensured in a simple manner in this relay.

According to the invention, this object is achieved in the case of such a relay with the following additional features:
the armature is mounted on the free end of the first core leg, and its free end forms the working air gap with the free end of a core leg lying outside the coil, and
the contact spring carries at least one contact piece on a central section and is connected at its other end section to the free end of the armature in such a way that the spring is stressed in its longitudinal direction essentially by the armature movement and that the contacting central section is thereby more or less bent.

In a preferred embodiment, the coil, the core and the armature enclose an essentially rectangular contact chamber on the base body, in which the contact elements are arranged to save space. Additional exemplary embodiments and developments of the invention are specified in the subclaims.

• Figur 1 eine erste Ausführungsform eines erfindungsgemäßen miniaturisierten elektromagnetischen Relais in vergrößertem Maßstab und in Explosionsdarstellung,
• Figur 2 und 3 zwei Draufsichten, teilweise geschnitten, auf das Relais von FIG 1 im unbetätigten und im betätigten Zustand,
• FIG 4 und 5 zwei entsprechende Ansichten zu FIG 2 und 3 auf ein Relais, dessen Anker und Kontaktelemente gegenüber den vorherigen FIG abgewandelt sind,
• FIG 6 eine Seitenansicht der Kontaktfeder gemäß FIG 4 und 5,
• FIG 7 und 8 vergrößerte Ausschnittsdarstellungen zur Erläuterung der Verbindungsstelle zwischen Anker und Kontaktfeder bei einem Relais gemäß FIG 4 und 5, wobei zwei aufeinanderfolgende Herstellungsschritte gezeigt sind,
• FIG 9 eine weitere Draufsicht entsprechend FIG 2 zur Darstellung eines dritten Ausführungsbeispiels des Relais mit einer nochmals abgewandelten Kontaktanordnung,
• FIG 10 eine Kontaktfeder aus FIG 9 in gestreckter Seitenansicht,
• FIG 11 und 12 weitere Draufsichten entsprechend FIG 2 auf zwei Relais mit abgewandelten Magnetsystemen.

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

• 1 shows a first embodiment of a miniaturized electromagnetic relay according to the invention on an enlarged scale and in an exploded view,
• Figures 2 and 3 two plan views, partially cut, on the relay of FIG 1 in the unactuated and in the actuated state,
• 4 and 5 show two views corresponding to FIGS. 2 and 3 of a relay, the armature and contact elements of which have been modified compared to the previous FIG.
• 6 shows a side view of the contact spring according to FIGS. 4 and 5,
• 7 and 8 enlarged sectional views for explaining the connection point between armature and contact spring in a relay according to FIGS. 4 and 5, two successive production steps being shown,
• 9 shows a further top view corresponding to FIG. 2 to show a third exemplary embodiment of the relay with a further modified contact arrangement,
• 10 shows a contact spring from FIG. 9 in an elongated side view,
• 11 and 12 further top views corresponding to FIG. 2 on two relays with modified magnet systems.

The relay shown in FIGS. 1 to 3 according to a first embodiment of the invention has a base body 1, a coil 2, a core 3, an armature 4 and contact elements 5, 6 and 7. The base body 1 has a base 11 and a circumferential side wall 12 , so that a box-shaped housing for the functional parts of the relay is formed in this way. This base body is made of insulating plastic material in a conventional manner, for example by pressing in the mold or by injection molding. In addition, the base body 1 contains partition walls 13 perpendicular to the floor for fastening parts and for ensuring insulation between metallic parts of the relay. The bottom 11 has openings 14 for Recording and fastening of connection elements for contacts and coil ends. In addition, the side walls 12 have a bearing web 15 and a stop 16 for the armature 4th

The electromagnetic system comprises a coil 2 with a coil body 21 which carries a winding 22; the coil former 21 also has extensions 23 in a flange region, in which connection pins are anchored and connected to the corresponding ends of the winding 22. In the exemplary embodiment shown, the coil is shown as being completely embedded in insulating material, this insulating material forming a sheath 25 which can be obtained, for example, by extrusion coating. However, the insulation between the coil winding 22 and the other metallic parts of the relay, for example the contact elements, can also be achieved in other conventional ways. For example, the coil could be inserted into a preformed cap or a coil housing made of insulating material. As additional insulation between the coil and contacts, the base body has the partition walls 13 described above. As can also be seen from FIG. 1, the connecting pins 24 are bent or cranked below the coil, so that they fit into a predetermined connection grid.

The ferromagnetic core 3 has essentially three legs, a first core leg 31 which is arranged axially inside the coil, a second core leg 32 which extends outside the coil at right angles to the first core leg, and a third core leg 33 which in turn extends at right angles extends to the second core leg and parallel to the first core leg and also has a certain distance from the coil. At its free end, the first core leg forms a bearing surface 34 for a corresponding bearing section 34a of the armature 4. For the sake of simplicity, the bearing surface 34 is drawn as flat. In practice it could they are also designed, for example, in a curved manner in order to keep the magnetic flux transition constant during the switching. In addition, the third core leg 33 has a free end, which serves as a pole face 35 and faces the pole face 44 at the free end of the armature 4.

The armature 4 is essentially elongated or bar-shaped. Its first end 41 is slightly embossed or cranked to form a bearing section 41 a which can be pivotably supported on the bearing surface 34 of the core leg 31, and the armature is secured against wandering away in its bearing position by the bearing web 15 of the base body 1. The end 42 of the armature 4 has a short angled arm 43 which forms a movable pole face 44 opposite the pole face 35 of the core. A working air gap 36 is thus formed between the pole faces 35 and 44. In the angle between the main part or the first arm of the armature 4 and the short bent arm 43, a slot 45 is formed which receives one end of the contact spring 7. However, this slot could also be provided without the arm 43 being bent.

The contact arrangement comprises a first fixed mating contact element 5, which carries a normally closed contact piece 51 on an upwardly bent section 52. The upwardly bent section 52 is carried by a central section 53 which lies flat on the bottom 11 of the base body 1. A second mating contact element 6 has a working contact piece 61 which is fastened to a resilient section 62, the resilient section 62 being produced from a leaf spring and being fastened to the second mating contact element 6 in a conventional manner, for example by riveting or welding. A middle section 63 is arranged parallel to the base 11 of the base body and rests thereon. Each of the two counter-contact elements 5 and 6 has a connection element 54 and 64, which is integrally formed on the associated contact element.

The movable part of the contact arrangement is formed by the contact spring 7, which carries a leaf spring 71 with contact pieces 72 and 73 on the two opposite sides of its central section 71a, in order in this way to form a working and a normally closed contact with the corresponding mating contact pieces 51 and 61 . The contact spring 7 has a connection element 74 which is connected to the leaf spring in a conventional manner, for example by riveting or welding.

In addition, the relay has a cover 8, which is shown in the form of a plate in FIG. This lid can be connected to the upper edge 17 of the side walls 12 of the base body 1 by means of adhesive or by ultrasonic welding or in any other suitable way. The cover 8 can also have another shape with which it can be attached to the base body 1 and connected to it with a seal, if necessary.

The assembly of the relay according to FIG 1 to 3 will now be described in detail. First, the parts shown in FIG. 1 are prefabricated, and the core is inserted with its first core leg 31 into an axial opening in the coil. Then the unit of coil and core thus obtained is inserted into the base body, the core legs 32 and 33 being clamped between the side walls 12 and the partition walls 13 of the base body 1. The contact elements are fastened by inserting the connection elements 54, 64 and 74 into corresponding openings 14 in the base body. The armature 4 is then inserted into the space between the coil and the side walls 12 of the base body. With this step, the free end 75 of the contact spring 7 is also inserted into the slot 45 of the armature. If necessary, the contact elements, in particular the second counter-contact element 6, can be adjusted by bending, for example by bending on the section 65. The relay is then placed on the cover 8 Base body 1 completed, the gap between the base body and cover being sealed as required.

The function of the relay described above can easily be seen from FIGS. 2 and 3. 2 shows the relay in the idle state when the coil is not energized. In this state, the contact spring 71 can relax at least partially and strives to stretch, pressing the armature 4 into its rest position against the stop 16 of the base body. In this position, the contact piece 72 is in contact with the contact piece 51, whereby a normally closed contact is formed. When the coil is excited and the armature 4 is thus attracted to the yoke leg 33, the contact spring 71 is compressed and bent in its longitudinal direction by the armature movement, as a result of which it closes the working contact between the contact pieces 73 and 61. This is the position shown in FIG. 3.

Modified exemplary embodiments are shown in the further FIG. In this FIG, the base body and the coil are only indicated schematically. In all of these embodiments, however, these parts are designed essentially as in the embodiment of FIG. 1, at most modified to adapt to different shapes of the core, the armature or the contact elements.

4 and 5 show a modified embodiment of the relay with a base body 1 and a coil 2 corresponding to the relay of FIG 1. A core 31 in this case comprises a first core leg 131, which is arranged within the coil 2, and a second core leg 132, which extends at right angles to the first core leg 131, specifically outside the coil. An anchor 140 has a first anchor arm 141 with a shape similar to that of anchor 4 in FIGS. 1 to 3 and a second anchor arm 142 which is at right angles to one another the first anchor arm 141 and extends parallel to the first core leg 131. In addition, a short bent arm 143 is provided at the free end of the second armature arm 142 in order to form an enlarged working air gap 136 with respect to the second core leg 132. As in FIGS. 1 to 3, the parts of the core and the armature lying outside the coil form a rectangular space together with the coil in this example, in order to form a contact chamber 9 in this way. A main advantage of this design arises from the fact that the armature length of the relay can have the longest possible extent within the relay volume, thereby obtaining the greatest possible stroke of the free armature end, while at the same time achieving the greatest possible distance between the switching contacts. In addition, by pressurizing the contact spring, a deflection of the spring in its central section is generated at least partially in its longitudinal direction, which is greater than the armature stroke.

In the exemplary embodiment according to FIGS. 4 and 5, the contact arrangement also has a design which differs from the first described example. The contact spring 170 consists of two spring sections 171 and 172, which have a fork-shaped design. These two spring portions are joined together at one end by welding or other suitable means, thereby forming a pointed end 175 which carries contact pieces 173 and 174 on the two opposite side surfaces. This pointed end 175 of the contact spring is arranged between the fixed mating contact elements 150 and 160 with the contact pieces 151 and 161, respectively, in such a way that a normally closed contact and a working contact with the contact spring 170 are formed.

The contact spring 170 can be made from two pieces as described above. However, it is also possible to form them from a leaf spring piece according to FIG. 6 with two slots 176 and 177. The three stripes in the shape of a comb are connected together so that they carry the pointed end 175 and the contact pieces 173 and 174 at the connecting end. The middle strip forms the spring section 172, while the two outer strips form the spring section 171, which carries the switching current between the connection element 178 and the contact pieces 173 and 174.

The contact spring section 172 can preferably be fastened to the armature arm 143 as shown in FIGS. 7 and 8, wherein insulation between the armature and the contact spring is also ensured. As shown in FIG. 7, a plastic rivet 10 is inserted with its molded-on pin 101 into a hole 144 in the armature arm 143. The contact spring section 172 has an opening 179, which is wider than the rear pin 102 of the plastic rivet 10. When the armature 140 and the contact spring 170 are now assembled, the opening 179 receives the rear pin 102 and can then still be aligned by sliding in the longitudinal direction or adjusted. When the spring is adjusted, the rear pin 102 of the plastic rivet is deformed by heat generated, for example, by an ultrasound device, and in this way the spring portion 172 is attached to the armature arm 143, as shown in FIG.

The relay shown in FIG. 9 has essentially the same structure of the magnet system as in the arrangement of FIG. 4. Therefore, the corresponding parts are also provided with the same reference numerals. With regard to these parts, reference is made to the description of FIG. 4. In deviation from the relay according to FIG. 4, the embodiment of FIG. 9 has a modified contact arrangement, which will now be described below.

A first fixed mating contact element 250 is in the Base body 1 anchored in a similar manner to the counter-contact element 5. This first mating contact element 250 carries a contact piece 251 on its section 252 which is bent upwards vertically, in order to form a working contact. A second mating contact element 260 is also anchored in the base body 1 in a manner similar to the mating contact element 160 in FIG. 4. This mating contact element 260 has a contact piece 261 on its bent section 262, so as to form a normally closed contact. The contact pieces 251 and 261 face each other and form a contact distance in which a central section 271 of a contact spring 270 is arranged. This middle section 271 carries contact pieces 272 and 273 on its two side surfaces in order in this way to form the working or rest contact with the opposing contact pieces 251 and 261, respectively. The contact spring 270 has an approximately rectangular shape, which is approximately adapted to the inside of the contact chamber formed by the coil 2, the core leg 132 and the armature legs 141 and 142 (it should be mentioned that because of the metallic parts, the inside of the contact chamber is partially replaced by additional ones Partitions 13 are formed). The contact spring 270, which is shown in the stretched state in FIG. 10, is connected with its first end section 274 to a connecting element 275 and with a second end section 276 to the armature arm 143. For example, it can be connected to the anchor in the same way as shown in FIGS. 4, 7 and 8.

FIGS. 11 and 12, which each show schematic top views, show two further possible embodiments, the contact chamber being outside the arrangement of the core and armature. In these cases, the insulation between the contact elements and the armature and the core can be achieved in a simpler manner, but the armature stroke may become somewhat shorter than in the previous exemplary embodiments if the same overall size of the relay is used.

The relay shown in FIG. 11 has a base body 410 with side walls 412, which could also be modified to match the function and the parts of the relay. A coil 420 with a shape similar to the coil 2 in FIG. 1 is arranged on or in the base body 410, and the core 430 is arranged with a first leg 431 inside the coil 420, while a second core leg 432 is perpendicular to the first core leg 431 extends outside the coil. An essentially L-shaped armature 440 is pivotably mounted with a first arm 441 on a free end 434 of the core 430. A second arm 442 of armature 440 forms a working air gap 436 with the second core leg 432. A short bent arm 443 is also provided to increase the effective area of the working air gap. It should also be mentioned that FIG. 11 shows the armature in the actuated state and that all parts shown there are only shown schematically. The details of the anchor, the bearing and other parts can be easily supplemented by a specialist. Outside the approximately rectangular arrangement of armature and core, a contact chamber 490 is formed on the base body 410. In this contact chamber, two fixed counter-contact elements 450 and 460 and a contact spring 470 are provided, which are similar in shape and function to the contact elements 150, 160 and 170 in the embodiment of FIG. 4. Minor modifications can easily be carried out by a person skilled in the art. Additional partition walls for improving the insulation between the metallic parts of the relay can also be provided in accordance with the principles and the basic ideas of the parts described and shown above.

A further modification of the relay is shown in FIG. In this exemplary embodiment, a coil 520 with a core 530 and an armature 540 is arranged on a base body 510. The core 530 has a first core leg 531, which is arranged in the coil, and a second Core leg 532, which extends at right angles to it outside the coil. The essentially L-shaped armature is pivotably mounted with a first arm 541 on the free end of the first core arm 531, while the second arm 542 forms a working air gap 536. In this case, in order to enlarge the effective area of the working air gap 536, the second core leg has an extension or a short bent arm 533.

Outside of the arrangement of the coil, core and armature, a contact chamber 590 is formed on the base body 510. In this contact chamber, a contact arrangement similar to that shown in FIG. 2 is provided, which comprises two fixed mating contact elements 550 and 560 and a contact spring 570, the latter being actuated by the armature in a manner similar to the contact spring 7 by the armature 4 in the first described embodiment. In this embodiment too, a person skilled in the art could carry out suitable modifications of the contact parts and of the other functional elements of the relay. In particular, suitable insulation between the arrangement of the coil and core on the one hand and the contact arrangement could be carried out by using suitable insulating or partition walls on the base body 510.

It should also be mentioned that further embodiments of the invention could be formed by further combinations of the different magnet systems shown and described on the one hand and contact arrangements on the other.

Claims (13)

1. Electromagnetic relay having the following features:

   a) a base body (1; 410; 510) has at least one flat base side (11);

   b) a coil (2; 420; 520) is arranged on the base body with its axis parallel to the base side;

   c) a bent core (3; 130; 430; 530) has at least two mutually perpendicular limbs which all lie in a common plane parallel to the base side, a first limb (31; 131; 431; 531) being arranged axially inside the coil and a second limb (32, 132; 432; 532) extending outside the coil at right angles to the first limb, and at least the first limb having a free end;

   d) an armature (4; 140; 440; 540) likewise extends in a plane parallel to the base side, is supported such that it can pivot on the free end of one of the core limbs and forms an operating air gap with the free end of another core limb, and

   e) a contact arrangement has at least one moving contact spring (7; 170; 270; 470; 570) and has at least one stationary mating contact element (5, 6; 150, 160; 250, 260; 450, 460; 550, 560) which is in each case firmly clamped in by means of an end section (74; 171; 274) and is connected to a connecting element (54; 64; 74) which is anchored in the base body,

   characterized by the following additional features:

   f) the armature (4; 140; 440; 540) is supported on the free end of the first core limb (31; 131; 431; 531), and its free end forms the operating air gap (36; 136; 436; 536) with the free end of a core limb (33; 132; 432; 532) which is located outside the coil, and

   g) the contact spring (7; 170; 270; 470; 570) carries at least one contact element on a centre section (71a; 175; 271) and is connected by means of its other end section (75; 172; 276) to the free end of the armature in such a manner that the spring is stressed essentially in its longitudinal direction by the armature movement and in that, in consequence, the contact-making centre section is bent to a greater or less extent.
2. Relay according to Claim 1, characterized in that the core (3) has a third limb (33) at right angles to the second limb and parallel to the first limb, the operating air gap (44) being formed between the armature (4) and the third limb of the core (33), in that the armature (4) is constructed essentially in an elongated manner, and in that the coil (2), the second and third core limbs (32, 33) and the armature (4) enclose an essentially rectangular contact space (9) on the base body (1) in which contact space (9) the contact elements (5, 6, 7) are arranged.
3. Relay according to Claim 1, characterized in that the armature (140) is of L-shaped construction, a first armature arm (141) being supported on the first core limb (131) and a second armature arm (142) extending outside the coil essentially parallel to the first core limb (131), and the operating air gap (136) being formed between the second core limb (132) and the second armature limb (142), and in that the coil (2), the core limb (132) and the armature (140) enclose an essentially rectangular contact chamber (9), on the base body (1), in which contact chamber (9) the contact elements (150, 160, 170; 250, 260, 270) are arranged.
4. Relay according to Claim 1, characterized in that the L-shaped armature (440) is supported on a first core limb (431) by means of a first arm (441), in that the second armature arm (442), which is approximately at right angles to the first armature arm, extends essentially parallel to the first core limb (431) close to the coil, the free ends of the second armature arm and of the second core limb forming the operating air gap (436), and in that the base body (410) forms an extension in the direction at right angles to the coil axis beyond the second armature arm (442), on which a contact chamber (490) is constructed which contains the contact arrangement (450, 460, 470).
5. Relay according to Claim 1, characterized in that the L-shaped armature (540) is supported on the first core limb (531) by means of its first arm (541), in that the second armature arm (442) extends essentially at right angles to the first armature arm (541) and parallel to the first core limb (531) alongside the coil, the free ends of the second armature arm (542) and of the second core limb (532) forming the operating air gap (536), and in that the base body forms an extension in the direction of the coil axis, beyond the second core limb (532), on which extension a contact chamber (590) is constructed which contains the contact arrangement (550, 560, 570).
6. Relay according to Claim 2 or 4, characterized in that the contact spring (7; 570), which is constructed in the shape of an arc, is arranged diagonally in the contact chamber (9; 590) and is clamped by means of its ends between its connecting element (74) and the armature (4, 540) in such a manner that the contact spring is bent less in the quiescent state of the armature and more in the pulled-in state of the armature.
7. Relay according to Claim 3 or 5, characterized in that the contact spring (170; 470) has a forked shape with a centre section (175) running to a tip and approximately parallel end sections (171, 172), this centre section (175) carrying contact elements (173, 174) which are fitted on the sides, and in that the two end sections (171, 172) are connected to a connecting element and to the armature respectively.
8. Relay according to Claim 3, characterized in that the contact spring (270) runs approximately along the inner walls of the contact chamber (9), its first end section (274) being connected on one side of the base body, in the vicinity of the second core limb (132), to the associated connecting element (275), its centre section (271) being located on the opposite side of the base body in the vicinity of the first armature arm (141) between two mating contact elements (250, 260), and its second end section (276) extending approximately parallel to the second armature arm (142) and being connected thereto at its free end.
9. Relay according to Claim 7 or 8, characterized in that the second end section (172; 276) of the contact spring (170; 270) is coupled to the armature (140) by means of an insulating plastic rivet (10).
10. Relay according to one of Claims 1 to 9, characterized in that two mutually opposite mating contact elements (5, 6) are provided which enclose the centre section of the contact spring (7) and of which one is rigid and the other (6) at least partially sprung, and in that the centre section (71a) of the contact spring (7) touches the rigid mating contact element (5) in the quiescent state of the armature (4) and touches the sprung mating contact element (6) in the pulled-in state of the armature.
11. Relay according to one of Claims 1 to 10, characterized in that the base body (1; 410; 510) has side walls (12) which are at right angles to the base side and which, with the base side (11) and a cover (8), form a housing.
12. Relay according to one of Claims 1 to 11, characterized in that the base body (1; 410; 510) has additional separating walls (13) and/or projections (15, 16) for the attachment and insulation of the coil, core and contact elements.
13. Relay according to one of Claims 1 to 12, characterized in that stops (15, 16) for the armature (4) are integrally formed on the base body (1).

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