EP0170173B1 - Piezoelectric relay - Google Patents

Piezoelectric relay Download PDF

Info

Publication number
EP0170173B1
EP0170173B1 EP85109069A EP85109069A EP0170173B1 EP 0170173 B1 EP0170173 B1 EP 0170173B1 EP 85109069 A EP85109069 A EP 85109069A EP 85109069 A EP85109069 A EP 85109069A EP 0170173 B1 EP0170173 B1 EP 0170173B1
Authority
EP
European Patent Office
Prior art keywords
longitudinal transducer
longitudinal
spring
bent spring
relay according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85109069A
Other languages
German (de)
French (fr)
Other versions
EP0170173A1 (en
Inventor
Klaus Dipl.-Ing. Lüneburger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0170173A1 publication Critical patent/EP0170173A1/en
Application granted granted Critical
Publication of EP0170173B1 publication Critical patent/EP0170173B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H57/00—Electrostrictive relays; Piezoelectric relays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H57/00—Electrostrictive relays; Piezoelectric relays
    • H01H2057/003—Electrostrictive relays; Piezoelectric relays the relay being latched in actuated position by magnet

Definitions

  • the invention relates to a piezoelectric relay with at least one piezoceramic longitudinal transducer whose change in length when a voltage is applied causes a proportional change in the clamping length of at least one contact element designed as an articulated spring, the central region of the articulated spring executing a transverse movement relative to at least one mating contact element.
  • Electromagnetic systems in a wide variety of designs have always been used to drive relays, the excitation coil of which can have undesirable effects on the relay function due to its heating and through contact-damaging evaporation of the winding insulation.
  • the use of the piezoelectric effect for switching relay contacts was also considered a long time ago.
  • the shape change of piezoelectric transducer elements is only small compared to their size, the performance characteristics of electromagnetic relays have not been able to be achieved with such designs.
  • the contact element is connected directly to a bending transducer, so that the deflection of the bending element directly results in the contact stroke.
  • the bending transducer and thus the relay as a whole have to be of a size which does not allow economical use of such relays for most fields of application. If the transducer is at the same time the carrier of the contact pieces, the current leads and possibly additional magnetic components, the transducer function is influenced by the electrical field of the switching voltage, while the heating of the contact pieces by the switching current can impair the transducer material itself.
  • a piezoelectric relay of the type mentioned is already known from US-A-4,454,442.
  • the longitudinal converter and the buckling spring are arranged abutting each other in the longitudinal direction, and this arrangement of the longitudinal converter and buckling spring is clamped with the free ends between the housing walls.
  • the change in length of the longitudinal converter required for switching depends on its absolute length, and relatively large changes in length are required for switching contact springs, the series arrangement of converter and contact spring results in an overall length which is undesirably large for practical use.
  • a piezoelectrically actuated switching device is known from US Pat. No. 3,688,135, in which contact springs are arranged parallel to a bending transducer and are pressurized in the longitudinal direction by a snap spring. This results in a bistable switching behavior.
  • the object of the invention is a piezoelectric. cal relay of the type mentioned to create with at least one longitudinal converter, in which a force-displacement characteristic similar to electromagnetic relays can be realized in a simple and space-saving design.
  • this object is achieved in that the buckling spring is clamped essentially parallel to the longitudinal converter, its clamping length being changeable in the same direction by the change in length of the longitudinal converter and by means of elastic prestressing being brought into non-positive pressure connection with the end faces of the longitudinal converter.
  • the change in length of the longitudinal transducer or elongator is therefore transferred to an articulated spring, that is to say a leaf spring which is subjected to buckling.
  • This buckling spring is more or less bent in proportion to the length of the longitudinal transducer, with its central region moving perpendicular to the longitudinal axis of the elongator. In this way, a deflection can be achieved which results in a usable contact path if the buckling spring is designed as a contact element in its central region.
  • the buckling spring In the de-energized state of the longitudinal converter, the buckling spring is essentially stretched, it being expedient to provide a slight deflection of the spring in this state as well, in order to permit buckling only in a defined direction when the longitudinal converter responds. With such a slight deflection, a sufficient contact force of the buckling spring can be applied to a mating contact element even in this switching position.
  • the invention not only achieves the basic advantage of a piezoelectric relay, namely the avoidance of an excitation coil and the problems associated with it, but rather it is achieved by separating the piezokerami see converter from the contact element possible to achieve the desired switching behavior in a simpler manner.
  • the piezoceramic linear transducer has no contact current leads, no contact pieces or magnetic components. Its change in length is transferred to the buckling spring, sufficient contact paths being achievable with such an arrangement. The stroke can be increased if the buckling spring is removed from the axis of the longitudinal converter and the change in length of the converter is transferred to the spring via a lever system.
  • a monostable system When using a longitudinal converter with one or more buckling springs, a monostable system is obtained.
  • a bistable version could also be created if two transducers are used, one of which causes a positive change in length via a pivot point and a lever. In this case, however, the construction becomes more complicated.
  • the buckling spring In the de-energized state of the longitudinal converter, the buckling spring is stretched in one embodiment of the invention. In order to obtain contact force for this position, the spring must be bent out of its rest position by a counter contact. This measure also ensures that when the longitudinal converter responds, the spring is bent only in a defined direction. In the rest position, the contact force can thus be generated solely by the rigidity of the slightly deflected spring, without the tensile action of the longitudinal converter having to make any contribution to this. In certain applications, this pulling action could also be used.
  • the piezoelectric relay shown in FIG. 1 contains a longitudinal transducer 2 in a housing 1, which is attached to the housing with one end 2a and is freely movable in the direction of its longitudinal axis with its free end 2b.
  • a change in length, namely a shortening, of the longitudinal converter takes place, which is noticeable in a displacement of the end face at the end 2b.
  • a kink spring 3 designed as a leaf spring is provided, which is coupled at its ends to the ends of the longitudinal converter 2, that is to say at the end 3a with the end 2a and at the end 3b with the end 2b.
  • the buckling spring 3 has a contact piece 4 which can be switched between two counter-contact elements 5 and 6.
  • Contact connection elements for the contact piece 4 and for the counter-contact elements 5 and 6 are not specifically shown, but they must be provided in the usual way.
  • a pressure spring 7 is provided for coupling between the longitudinal converter 2 and the buckling spring 3, which presses the end 3b onto the end face at the converter end 2b.
  • the buckling spring 3 assumes the solid line shape in FIG. 7.
  • the contact piece 4 rests on the mating contact element 5, as a result of which the articulated spring 3 is bent slightly to the left from the elongated shape. If the converter element 2 is connected to voltage via connection elements (not shown), it shortens and the end 2b moves upward in FIG. 1. The buckling spring 3 is thus strongly bent to the left, the contact piece 4 being pressed against the mating contact 6. The spring 3 then takes the dashed shape 3c. After switching off the voltage on the longitudinal converter 2, the spring returns to its initial position or initial shape.
  • Fig. 2 shows a modification to Fig. 1 in such a way that the buckling spring 3 is offset with its longitudinal axis with respect to the longitudinal axis of the longitudinal converter 2, the change in length of the longitudinal converter 2 is transmitted to the buckling spring 3 via a lever 8.
  • This enables a larger contact stroke.
  • the mode of operation of the relay corresponds to the embodiment of FIG. 1.
  • Such a system is also shown in FIG. 3.
  • the lever arm 8 is also supported with its end 8a in the housing 1 and is pressed against the free end of the longitudinal converter 2 via a leaf spring 17.
  • the lever arm 8 is firmly clamped in the housing 1 in the area 1a, in such a way that it receives a pretension towards the free end of the longitudinal converter 2.
  • the lever arm 8 follows it and thus switches the contact piece 4 from the mating contact element 5 to the mating contact element 6.
  • the buckling spring 3 is clamped between two lever arms 18a and 18b, which in turn are clamped in the housing part 19 in such a way that they press on the end faces of the longitudinal converter 2 from both sides.
  • the function of the relay is the same as in the previous example.
  • the longitudinal converter 2 is between two pressure plates 28a and 28b clamped, which form a pressure frame with two buckling springs 23a and 23b, which surrounds the longitudinal converter 2.
  • the two buckling springs 23a and 23b are biased into a more curved shape; if the longitudinal converter shortens, they bend more and switch from the normally closed contacts 25a and 25b to the normally open contacts 26a and 26b.
  • the two buckling springs 23a and 23b can be electrically connected via the pressure plates and act as a bridge contact without their own connection. If these buckling springs 23a and 23b are insulated from one another and each provided with their own connections, two changeover switches are formed.
  • two pressure plates 38a and 38b are tensioned with a tensioning band 39 on the two end faces of the longitudinal converter 2.
  • the tension band 39 surrounds the longitudinal converter in such a way that it is under pressure in its longitudinal direction.
  • a permanent magnet system can be provided in addition to generating a tilting characteristic and increasing the contact force. 8 and 9, an embodiment for such a permanent magnet system is schematically provided.
  • a permanent magnet 40 is arranged between two pole shoes 41 and 42, the free pole surfaces of which are each brought up to the mating contact elements 5 and 6.
  • Such a permanent magnet system can be used in this or in a modified form for all previously described relay systems.

Landscapes

  • Mechanisms For Operating Contacts (AREA)
  • Contacts (AREA)

Description

Die Erfindung bezieht sich auf ein piezoelektrisches Relais mit mindestens einem piezokeramischen Längswandler, dessen Längenänderung beim Anlegen einer Spannung eine proportionale Änderung der Einspannlänge mindestens eines als Knickfeder ausgebildeten Kontaktelements bewirkt, wobei der Mittelbereich der Knickfeder relativ zu mindestens einem Gegenkontaktelement eine Transversalbewegung ausführt.The invention relates to a piezoelectric relay with at least one piezoceramic longitudinal transducer whose change in length when a voltage is applied causes a proportional change in the clamping length of at least one contact element designed as an articulated spring, the central region of the articulated spring executing a transverse movement relative to at least one mating contact element.

Zum Antrieb von Relais werden seit jeher Elektromagnetsysteme in verschiedensten Ausführungsformen verwendet, deren Erregerspule durch ihre Erwärmung und durch kontaktschädliche Ausdünstungen der Wicklungsisolierung unerwünschte Auswirkungen auf die Relaisfunktion haben kann. Auf der Suche nach anderen Antriebssystemen wurde auch bereits vor langer Zeit eine Ausnutzung des piezoelektrischen Effekts zum Schalten von Relaiskontakten in Erwägung gezogen. Da die Formänderung piezoelektrischer Wandlerelemente jedoch im Vergleich zu ihrer Größe nur gering ist, konnten mit derartigen Konstruktionen bisher die Leistungseigenschaften elektromagnetischer Relais nicht erreicht werden.Electromagnetic systems in a wide variety of designs have always been used to drive relays, the excitation coil of which can have undesirable effects on the relay function due to its heating and through contact-damaging evaporation of the winding insulation. When looking for other drive systems, the use of the piezoelectric effect for switching relay contacts was also considered a long time ago. However, since the shape change of piezoelectric transducer elements is only small compared to their size, the performance characteristics of electromagnetic relays have not been able to be achieved with such designs.

So ist bei bekannten piezoelektrischen Relais (DE-U-19 17 876, DE-A-28 11 524) jeweils das Kontaktelement unmittelbar mit einem Biegewandler verbunden, so daß die Auslenkung des Biegeelementes unmittelbar den Kontakthub ergibt. Um bei derartigen Relais einen genügend großen Kontakthub zu erhalten, müssen der Biegewandler und damit das Relais insgesamt eine Größe erhalten, die für die meisten Anwendungsgebiete einen wirtschaftlichen Einsatz derartiger Relais nicht ermöglicht. Ist der Wandler gleichzeitig Träger der Kontaktstücke, der Stromzuführungen und evtl. zusätzlicher magnetischer Bauteile, so wird die Wandlerfunktion durch das elektrische Feld der Schaltspannung beeinflußt, während die Erwärmung der Kontaktstücke durch den Schaltstrom das Wandlermaterial selbst beeinträchtigen kann. Außerdem gibt es Probleme, zwischen dem Kontaktmaterial und der Wandlerkeramik eine haltbare Verbindung herzustellen, die keine Bimetall-Wirkung haben darf. Von Nachteil ist auch, daß die Wandler aufgrund ihrer Eigenschaften (Hysterese, Schleichen, Reihenfolge der Betätigungen) keine konstanten Kontaktkräfte ermöglichen.In known piezoelectric relays (DE-U-19 17 876, DE-A-28 11 524), the contact element is connected directly to a bending transducer, so that the deflection of the bending element directly results in the contact stroke. In order to obtain a sufficiently large contact stroke with such relays, the bending transducer and thus the relay as a whole have to be of a size which does not allow economical use of such relays for most fields of application. If the transducer is at the same time the carrier of the contact pieces, the current leads and possibly additional magnetic components, the transducer function is influenced by the electrical field of the switching voltage, while the heating of the contact pieces by the switching current can impair the transducer material itself. There are also problems in creating a durable connection between the contact material and the transducer ceramic, which must not have a bimetal effect. Another disadvantage is that the transducers do not allow constant contact forces due to their properties (hysteresis, creep, sequence of operations).

Ein piezoelektrisches Relais der eingangs genannten Art ist bereits aus der US-A-4,454,442 bekannt. Dort sind jeweils der Längswandler und die Knickfeder in Längsrichtung aneinanderstoßend angeordnet, und diese Anordnung von Längswandler und Knickfeder ist mit den freien Enden zwischen Gehäusewänden eingespannt. Da jedoch die zum Schalten erforderliche Längenänderung des Längswandlers von seiner absoluten Länge abhängt, und zum Schalten von Kontaktfedern relativ große Längenänderungen notwendig sind, ergibt die Serienanordnung von Wandler und Kontaktfeder eine für den praktischen Einsatz unerwünscht große Gesamtlänge.A piezoelectric relay of the type mentioned is already known from US-A-4,454,442. There the longitudinal converter and the buckling spring are arranged abutting each other in the longitudinal direction, and this arrangement of the longitudinal converter and buckling spring is clamped with the free ends between the housing walls. However, since the change in length of the longitudinal converter required for switching depends on its absolute length, and relatively large changes in length are required for switching contact springs, the series arrangement of converter and contact spring results in an overall length which is undesirably large for practical use.

Aus IBM Technical Disclosure Bulletin, 1977, Heft 6, Seite 2263, ist auch bereits eine Anordnung bekannt, bei der ein Längswandler und eine Knickfeder zur Betätigung einer Druckernadel parallel zueinander angeordnet sind. Allerdings ist dort eine verhältnismäßig komplizierte Doppelhebelanordnung vorgesehen, um bei Längenänderung des Längswandlers eine gegensinnig proportionale Änderung der Einspannlänge der Knickfeder zu erreichen.An arrangement is also known from IBM Technical Disclosure Bulletin, 1977, volume 6, page 2263, in which a longitudinal converter and an articulated spring for actuating a printer needle are arranged parallel to one another. However, a relatively complicated double lever arrangement is provided there in order to achieve an oppositely proportional change in the clamping length of the buckling spring when the length of the longitudinal converter changes.

Weiterhin ist aus der US-A-3,688,135 eine piezoelektrisch betätigte Schalteinrichtung bekannt, bei der Kontaktfedern parallel zu einem Biegewandler angeordnet und durch eine Schnappfeder in Längsrichtung mit Druck beaufschlagt sind. Dadurch ergibt sich ein bistabiles Schaltverhalten.Furthermore, a piezoelectrically actuated switching device is known from US Pat. No. 3,688,135, in which contact springs are arranged parallel to a bending transducer and are pressurized in the longitudinal direction by a snap spring. This results in a bistable switching behavior.

. Aufgabe der Erfindung ist es, ein piezoelektri-. sches Relais der eingangs genannten Art mit mindestens einem Längswandler zu schaffen, bei dem eine Kraft-Weg-Charakteristik ähnlich wie bei elektromagnetischen Relais in einer einfachen und platzsparenden Konstruktion verwirklicht werden kann.. The object of the invention is a piezoelectric. cal relay of the type mentioned to create with at least one longitudinal converter, in which a force-displacement characteristic similar to electromagnetic relays can be realized in a simple and space-saving design.

Erfindungsgemäß wird diese Aufgabe dadurch gelöst, daß die Knickfeder im wesentlichen parallel zu dem Längswandler eingespannt ist, wobei ihre Einspannlänge durch die Längenänderung des Längswandlers gleichsinnig proportional veränderbar ist und durch Mittel zur elastischen Vorspannung in kraftschlüssige Druckverbindung mit den Stirnflächen des Längswandlers gebracht ist.According to the invention, this object is achieved in that the buckling spring is clamped essentially parallel to the longitudinal converter, its clamping length being changeable in the same direction by the change in length of the longitudinal converter and by means of elastic prestressing being brought into non-positive pressure connection with the end faces of the longitudinal converter.

Bei der Erfindung wird also die Längenänderung des Längswandlers bzw. Elongators auf eine Knickfeder, also eine auf Knickung beanspruchte Blattfeder, übertragen. Proportional zur Länge des Längswandlers wird diese Knickfeder mehr oder weniger durchgebogen, wobei sich ihr Mittelbereich senkrecht zur Längsachse des Elongators bewegt. Auf diese Weise läßt sich eine Auslenkung erreichen, die einen brauchbaren Kontaktweg ergibt, wenn die Knickfeder in ihrem Mittelbereich als Kontaktelement ausgebildet ist. Im spannungslosen Zustand des Längswandlers ist die Knickfeder im wesentlichen gestreckt, wobei es zweckmäßig ist, auch in diesem Zustand eine leichte Durchbiegung der Feder vorzusehen, um beim Ansprechen des Längswandlers eine Ausknickung nur in einer definierten Richtung zuzulassen. Mit einer derartigen leichten Durchbiegung kann auch bei dieser Schaltstellung eine genügende Kontaktkraft der Knickfeder gegenüber einem Gegenkontaktelement aufgebracht werden.In the invention, the change in length of the longitudinal transducer or elongator is therefore transferred to an articulated spring, that is to say a leaf spring which is subjected to buckling. This buckling spring is more or less bent in proportion to the length of the longitudinal transducer, with its central region moving perpendicular to the longitudinal axis of the elongator. In this way, a deflection can be achieved which results in a usable contact path if the buckling spring is designed as a contact element in its central region. In the de-energized state of the longitudinal converter, the buckling spring is essentially stretched, it being expedient to provide a slight deflection of the spring in this state as well, in order to permit buckling only in a defined direction when the longitudinal converter responds. With such a slight deflection, a sufficient contact force of the buckling spring can be applied to a mating contact element even in this switching position.

Mit der Erfindung wird nicht nur der grundsätzliche Vorteil eines piezoelektrischen Relais, nämlich die Vermeidung einer Erregerspule und der mit ihr verbundenen Probleme, erreicht, vielmehr wird es durch die Trennung des piezokeramisehen Wandlers vom Kontaktelement möglich, das gewünschte Schaltverhalten auf einfachere Weise zu verwirklichen. Der piezokeramische Längswandler besitzt keine Kontakt-Stromzuführungen, keine Kontaktstücke oder magnetischen Bauelemente. Seine Längenänderung wird auf die Knickfeder übertragen, wobei mit einer derartigen Anordnung ausreichende Kontaktwege erreichbar sind. Eine Vergrößerung des Hubs ist möglich, wenn die Knickfeder von der Achse des Längswandlers entfernt wird und die Längenänderung des Wandlers über ein Hebelsystem auf die Feder übertragen wird.The invention not only achieves the basic advantage of a piezoelectric relay, namely the avoidance of an excitation coil and the problems associated with it, but rather it is achieved by separating the piezokerami see converter from the contact element possible to achieve the desired switching behavior in a simpler manner. The piezoceramic linear transducer has no contact current leads, no contact pieces or magnetic components. Its change in length is transferred to the buckling spring, sufficient contact paths being achievable with such an arrangement. The stroke can be increased if the buckling spring is removed from the axis of the longitudinal converter and the change in length of the converter is transferred to the spring via a lever system.

Bei Verwendung eines Längswandlers mit einer oder mehreren Knickfedern erhält man ein monostabiles System. Es könnte aber auch eine bistabile Ausführung geschaffen werden, wenn zwei Wandler verwendet werden, von denen einer über einen Drehpunkt und einen Hebel eine positive Längenänderung bewirkt. Die Konstruktion wird in diesem Fall jedoch komplizierter.When using a longitudinal converter with one or more buckling springs, a monostable system is obtained. However, a bistable version could also be created if two transducers are used, one of which causes a positive change in length via a pivot point and a lever. In this case, however, the construction becomes more complicated.

Im spannungslosen Zustand des Längswandlers ist die Knickfeder bei einer Ausführungsform der Erfindung gestreckt. Um für diese Stellung auch Kontaktkraft zu erhalten, muß die Feder durch einen Gegenkontakt etwas aus ihrer Ruhelage herausgebogen werden. Mit dieser Maßnahme wird auch sichergestellt, daß beim Ansprechen des Längswandlers eine Knickung der Feder nur in definierter Richtung erfolgt. In der Ruhelage läßt sich also die Kontaktkraft allein durch die Steifigkeit der geringfügig ausgelenkten Feder erzeugen, ohne daß die Zugwirkung des Längswandlers hierzu einen Beitrag leisten muß. In bestimmten Anwendungsfällen könnte auch diese Zugwirkung mit herangezogen werden.In the de-energized state of the longitudinal converter, the buckling spring is stretched in one embodiment of the invention. In order to obtain contact force for this position, the spring must be bent out of its rest position by a counter contact. This measure also ensures that when the longitudinal converter responds, the spring is bent only in a defined direction. In the rest position, the contact force can thus be generated solely by the rigidity of the slightly deflected spring, without the tensile action of the longitudinal converter having to make any contribution to this. In certain applications, this pulling action could also be used.

Die Erfindung wird nachfolgend an Ausführungsbeispielen anhand der Zeichnung näher erläutert. Es zeigt

  • Fig. 1 ein piezoelektrisches Relais mit einem Längswandler und einer unmittelbar an dem Längswandler angebrachten Knickfeder,
  • Fig. 2 einen Längswandler mit einer über ein Hebelsystem angekoppelten Knickfeder,
  • Fig. 3 bis 5 verschiedene Abwandlungen eines Längswandlers mit einer Knickfeder,
  • Fig. 6 einen Längswandler mit zwei rahmenartig angeordneten Knickfedern,
  • Fig. 7 einen Längswandler mit einem Druckrahmen und einer Knickfeder,
  • Fig. 8 und 9 ein in den vorhergehenden Ausführungsbeispielen anwendbares Dauermagnetsystem in zwei Ansichten.
The invention is explained in more detail below using exemplary embodiments with reference to the drawing. It shows
  • 1 shows a piezoelectric relay with a longitudinal transducer and an articulated spring attached directly to the longitudinal transducer,
  • 2 shows a longitudinal converter with an articulated spring coupled via a lever system,
  • 3 to 5 different modifications of a longitudinal converter with an articulated spring,
  • 6 shows a longitudinal converter with two buckling springs arranged in a frame-like manner,
  • 7 shows a longitudinal converter with a pressure frame and an articulated spring,
  • 8 and 9 a permanent magnet system applicable in the previous exemplary embodiments in two views.

Alle Zeichnungen zeigen lediglich den schematischen Aufbau des Relaissystems. Die konstruktive Ausgestaltung kann der Fachmann daraus ableiten.All drawings only show the schematic structure of the relay system. The person skilled in the art can derive the structural design from this.

Das in Fig. 1 dargestellte piezoelektrische Relais enthält in einem Gehäuse 1 einen Längswandler 2, der mit einem Ende 2a am Gehäuse befestigt ist und mit seinem freien Ende 2b in Richtung seiner Längsachse frei beweglich ist. Das bedeutet, daß beim Anlegen einer Spannung an den Längswandler 2 über nicht dargestellte Anschlußelemente eine Längenänderung, nämlich eine Verkürzung, des Längswandlers erfolgt, was sich in einer Verschiebung der Stirnseite am Ende 2b bemerkbar macht. Parallel zum Längswandler ist eine als Blattfeder ausgebildete Knickfeder 3 vorgesehen, welche mit ihren Enden jeweils mit den Enden des Längswandlers 2 gekoppelt ist, also am Ende 3a mit dem Ende 2a und am Ende 3b mit dem Ende 2b. Etwa in ihrer Mitte besitzt die Knickfeder 3 ein Kontaktstück 4, welches zwischen zwei Gegenkontaktelementen 5 und 6 umschaltbar ist. Kontaktanschlußelemente für das Kontaktstück 4 und für die Gegenkontaktelemente 5 und 6 sind nicht eigens dargestellt, doch müssen sie in üblicher Weise vorgesehen werden. Außerdem ist zur Kopplung zwischen Längswandler 2 und Knickfeder 3 eine Andruckfeder 7 vorgesehen, welche das Ende 3b auf die Stirnseite am Wandlerende 2b drückt.The piezoelectric relay shown in FIG. 1 contains a longitudinal transducer 2 in a housing 1, which is attached to the housing with one end 2a and is freely movable in the direction of its longitudinal axis with its free end 2b. This means that when a voltage is applied to the longitudinal converter 2 via connection elements, not shown, a change in length, namely a shortening, of the longitudinal converter takes place, which is noticeable in a displacement of the end face at the end 2b. Parallel to the longitudinal converter, a kink spring 3 designed as a leaf spring is provided, which is coupled at its ends to the ends of the longitudinal converter 2, that is to say at the end 3a with the end 2a and at the end 3b with the end 2b. Approximately in the middle, the buckling spring 3 has a contact piece 4 which can be switched between two counter-contact elements 5 and 6. Contact connection elements for the contact piece 4 and for the counter-contact elements 5 and 6 are not specifically shown, but they must be provided in the usual way. In addition, a pressure spring 7 is provided for coupling between the longitudinal converter 2 and the buckling spring 3, which presses the end 3b onto the end face at the converter end 2b.

Solange das Wandlerelement nicht erregt ist, nimmt die Knickfeder 3 die in Fig. 7 durchgezogene Linienform ein. Dabei liegt das Kontaktstück 4 auf dem Gegenkontaktelement 5 auf, wodurch die Knickfeder 3 leicht aus der gestreckten Form nach links durchgebogen ist. Wird das Wandlerelement 2 über nicht dargestellte Anschlußelemente an Spannung gelegt, so verkürzt es sich und das Ende 2b verschiebt sich in Fig. 1 nach oben. Damit wird die Knickfeder 3 stark nach links durchgebogen, wobei das Kontaktstück 4 gegen den Gegenkontakt 6 gedrückt wird. Die Feder 3 nimmt dann die gestrichelte Form 3c ein. Nach Abschalten der Spannung am Längswandler 2 kehrt die Feder wieder in ihre Ausgangslage bzw. Ausgangsform zurück.As long as the transducer element is not energized, the buckling spring 3 assumes the solid line shape in FIG. 7. The contact piece 4 rests on the mating contact element 5, as a result of which the articulated spring 3 is bent slightly to the left from the elongated shape. If the converter element 2 is connected to voltage via connection elements (not shown), it shortens and the end 2b moves upward in FIG. 1. The buckling spring 3 is thus strongly bent to the left, the contact piece 4 being pressed against the mating contact 6. The spring 3 then takes the dashed shape 3c. After switching off the voltage on the longitudinal converter 2, the spring returns to its initial position or initial shape.

Die Fig. 2 zeigt eine Abwandlung gegenüber Fig. 1 in der Weise, daß die Knickfeder 3 mit ihrer Längsachse gegenüber der Längsachse des Längswandlers 2 versetzt ist, wobei die Längenänderung des Längswandlers 2 über einen Hebel 8 auf die Knickfeder 3 übertragen wird. Dadurch ist ein größerer Kontakthub möglich. Ansonsten entspricht die Wirkungsweise des Relais der Ausführungsform von Fig. 1. Ein solches System ist auch in Fig. 3 dargestellt. Der Hebelarm 8 ist auch hier mit seinem Ende 8a im Gehäuse 1 gelagert und wird über eine Blattfeder 17 an das freie Ende des Längswandlers 2 angedrückt.Fig. 2 shows a modification to Fig. 1 in such a way that the buckling spring 3 is offset with its longitudinal axis with respect to the longitudinal axis of the longitudinal converter 2, the change in length of the longitudinal converter 2 is transmitted to the buckling spring 3 via a lever 8. This enables a larger contact stroke. Otherwise, the mode of operation of the relay corresponds to the embodiment of FIG. 1. Such a system is also shown in FIG. 3. The lever arm 8 is also supported with its end 8a in the housing 1 and is pressed against the free end of the longitudinal converter 2 via a leaf spring 17.

Bei der Ausführungsform von Fig. 4 ist der Hebelarm 8 im Gehäuse 1 im Bereich 1a fest eingespannt, und zwar so, daß er auf das freie Ende des Längswandlers 2 hin eine Vorspannung erhält. Bei Verkürzung des Längswandlers folgt ihm also der Hebelarm 8 und schaltet damit das Kontaktstück 4 vom Gegenkontaktelement 5 zum Gegenkontaktelement 6 um.In the embodiment of FIG. 4, the lever arm 8 is firmly clamped in the housing 1 in the area 1a, in such a way that it receives a pretension towards the free end of the longitudinal converter 2. When the longitudinal converter is shortened, the lever arm 8 follows it and thus switches the contact piece 4 from the mating contact element 5 to the mating contact element 6.

In Weiterbildung von Fig. 4 ist bei der Ausführungsform von Fig. 5 die Knickfeder 3 zwischen zwei Hebelarmen 18a und 18b eingespannt, welche ihrerseits in dem Gehäuseteil 19 so verspannt sind, daß sie von beiden Seiten auf die Stirnflächen des Längswandlers 2 drücken. Die Funktion des Relais ist die gleiche wie beim vorhergehenden Beispiel.In the embodiment of FIG. 4, the buckling spring 3 is clamped between two lever arms 18a and 18b, which in turn are clamped in the housing part 19 in such a way that they press on the end faces of the longitudinal converter 2 from both sides. The function of the relay is the same as in the previous example.

Bei der Ausführungsform von Fig. 6 ist der Längswandler 2 zwischen zwei Druckplatten 28a und 28b eingespannt, welche mit zwei Knickfedern 23a und 23b einen Druckrahmen bilden, der den Längswandler 2 umgibt. Die beiden Knickfedern 23a und 23b sind dabei in eine stärker gekrümmte Form vorgespannt; wenn der Längswandler sich verkürzt, biegen sie sich stärker durch und schalten von den Ruhekontakten 25a und 25b zu den Arbeitskontakten 26a und 26b um. Die beiden Knickfedern 23a und 23b können über die Druckplatten elektrisch verbunden sein und ohne eigenen Anschluß als Brückenkontakt wirken. Werden diese Knickfedern 23a und 23b voneinander isoliert und mit jeweils eigenen Anschlüssen versehen, so werden zwei Umschalter gebildet.In the embodiment of FIG. 6, the longitudinal converter 2 is between two pressure plates 28a and 28b clamped, which form a pressure frame with two buckling springs 23a and 23b, which surrounds the longitudinal converter 2. The two buckling springs 23a and 23b are biased into a more curved shape; if the longitudinal converter shortens, they bend more and switch from the normally closed contacts 25a and 25b to the normally open contacts 26a and 26b. The two buckling springs 23a and 23b can be electrically connected via the pressure plates and act as a bridge contact without their own connection. If these buckling springs 23a and 23b are insulated from one another and each provided with their own connections, two changeover switches are formed.

Bei der Ausführungsform gemäß Fig. 7 sind zwei Druckplatten 38a und 38b mit einem Spannband 39 auf die beiden Stirnseiten des Längswandlers 2 gespannt. Das Spannband 39, von dem in Fig. 7 lediglich eine Seite zu sehen ist, umgibt den Längswandler so, daß er in seiner Längsrichtung unter Druck steht. Bei Erregung und damit verbundener Verkürzung des Längswandlers 2 werden die Druckplatten 38a und 38b aneinander angenähert, so daß die zwischen ihnen gespannte Druckfeder 33 vom Gegenkontakt 35 auf den Gegenkontakt 36 umschaltet.In the embodiment according to FIG. 7, two pressure plates 38a and 38b are tensioned with a tensioning band 39 on the two end faces of the longitudinal converter 2. The tension band 39, of which only one side can be seen in FIG. 7, surrounds the longitudinal converter in such a way that it is under pressure in its longitudinal direction. When the longitudinal transducer 2 is excited and shortened, the pressure plates 38a and 38b are brought closer together so that the compression spring 33 stretched between them switches from the counter contact 35 to the counter contact 36.

Für alle Ausführungsformen kann zusätzlich zur Erzeugung einer Kippcharakteristik und zur Verstärkung der Kontaktkraft ein Dauermagnetsystem vorgesehen werden. In Fig. 8 und 9 ist schematisch eine Ausführungsform für ein derartiges Dauermagnetsystem vorgesehen. Dabei ist ein Dauermagnet 40 zwischen zwei Polschuhen 41 und 42 angeordnet, deren freie Polflächen jeweils an die Gegenkontaktelemente 5 und 6 herangeführt sind. Ein derartiges Dauermagnetsystem kann in dieser oder in einer abgewandelten Form für alle vorher beschriebenen Relaissysteme zur Anwendung kommen.For all embodiments, a permanent magnet system can be provided in addition to generating a tilting characteristic and increasing the contact force. 8 and 9, an embodiment for such a permanent magnet system is schematically provided. A permanent magnet 40 is arranged between two pole shoes 41 and 42, the free pole surfaces of which are each brought up to the mating contact elements 5 and 6. Such a permanent magnet system can be used in this or in a modified form for all previously described relay systems.

Claims (9)

1. Piezoelectric relay with at least one piezoceramic longitudinal transducer (2), the change in length of which on the application of a voltage causes a proportional change in the clamped length of at least one contact element constructed as bent spring (3 ; 23a, 23b ; 33), the central region of the bent spring (3 ; 23a, 23b ; 33) executing a transverse motion relative to at least one counter-contact element (5, 6 ; 25a, 25b, 26a, 26b ; 35, 36), characterized in that the bent spring (3 ; 23a, 23b ; 33)
is clamped essentially parallel to the longitudinal transducer (2), it being possible by means of the change in length of the longitudinal transducer (2) to change its clamped length proportionally in the same sense and
is brought into non-positive compressive connection with the end faces of the longitudinal transducer (2) through means for elastic biasing.
2. Relay according to Claim 1, characterized in that the bent spring (3) is coupled with its two ends (3a, 3b) directly to the ends (2a, 2b) of the longitudinal transducer (2), and is provided with contact surfaces (4) in its central region.
3. Relay according to Claim 1, characterized in that the ends of the bent spring (3) are coupled via a lever system to the ends of the longitudinal transducer (2).
4. Relay according to any of Claims 1 to 3, characterized in that the bent spring (3) or a lever arm (8) of the lever system is pressed against the longitudinal transducer (2) in the direction of reaction of the latter by means of a compression spring (7 ; 17).
5. Relay according to Claim 3, characterized in that a lever arm (8) for the bent spring (3) is biased in the direction of reaction of the longitudinal transducer (2) via a fixed clamping device (1 a) in a housing framework (1).
6. Relay according to Claim 3, characterized in that two lever arms (18a, 18b), clamped in a support (19) and provided for the ends of the bent spring (3), exert a bias on the two end faces of the longitudinal transducer (2).
7. Relay according to Claim 3, characterized in that two pressure plates (38a, 38b) are pressed against the end faces of the longitudinal transducer (2) by means of a pressure frame (39) enclosing the longitudinal transducer (2), and enclose at least one bent spring (33) with their free ends.
8. Relay according to Claim 3 or 7, characterized in that a bent spring (23a, 23b) is arranged respectively on either side of the longitudinal transducer (2), and in that a pressure plate (28a, 28b) lies respectively on either end face of the longitudinal transducer (2), the bent springs (23a, 23b) and pressure plates (28a, 28b) connected with one another at their ends forming a pressure frame for the longitudinal transducer (2), the pressure forces of which are produced by a - biasing if the bent springs (23a, 23b).
9. Relay according to one of Claims 1 to 8, characterized in that the contact-making section of the bent spring (3) is at least partially ferromagnetic, and lies between the pole shoes (41, 42) of a permanent magnet system.
EP85109069A 1984-07-24 1985-07-19 Piezoelectric relay Expired EP0170173B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3427294 1984-07-24
DE3427294 1984-07-24

Publications (2)

Publication Number Publication Date
EP0170173A1 EP0170173A1 (en) 1986-02-05
EP0170173B1 true EP0170173B1 (en) 1989-05-17

Family

ID=6241452

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85109069A Expired EP0170173B1 (en) 1984-07-24 1985-07-19 Piezoelectric relay

Country Status (2)

Country Link
EP (1) EP0170173B1 (en)
DE (1) DE3570319D1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19648730C2 (en) * 1996-11-25 1998-11-19 Fraunhofer Ges Forschung Piezo-electrically operated micro valve
DE19735156C1 (en) * 1996-11-25 1999-04-29 Fraunhofer Ges Forschung Piezo-electrically operated micro valve

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3688135A (en) * 1970-10-09 1972-08-29 Clare & Co C P Piezoelectrically actuated lever switch
DE2811524A1 (en) * 1978-03-16 1979-09-20 Siemens Ag Bistable piezoelectric relay with flexural element clamped at one end - has armature forming strip whose free end engages between magnetic system poles
US4318023A (en) * 1980-02-21 1982-03-02 Physics International Company Sagittally amplified piezoelectric actuator
US4454442A (en) * 1983-07-15 1984-06-12 General Dynamics Electronics Division Piezoelectric relay using Euler lever

Also Published As

Publication number Publication date
DE3570319D1 (en) 1989-06-22
EP0170173A1 (en) 1986-02-05

Similar Documents

Publication Publication Date Title
DE69606760T2 (en) Miniature device for performing a predetermined function, in particular micro-relay
AT396392B (en) PIEZO VALVE
EP0203515B1 (en) Electromagnetic relay
DE102007029633A1 (en) 2-pole relay
DE3236250C2 (en) Temperature-dependent electrical switching device
DE4009427C2 (en) Electromagnetic contactor
DE4118177C2 (en) Permanent magnetic residual current release
EP0022953B1 (en) Electromagnetic relay
EP0094045B1 (en) Contact arrangement for a relay
EP0326116A1 (en) Contact arrangement for a relay
EP0170173B1 (en) Piezoelectric relay
EP0170172B1 (en) Piezoelectric relay
EP0013991B2 (en) Arrangement of contact springs for polarized electromagnetic relays
EP0170958B1 (en) Piezoelectric relay
EP0433633B1 (en) Electromagnetic relay with a return spring
WO1998022966A1 (en) Electromagnetic switching device
DE3226350A1 (en) Push-button switch
DE3321561A1 (en) Switching device for a temperature switch or pressure switch
DE1127435B (en) Micro snap switch
WO2020053161A1 (en) Operator control device
DE102005033858B4 (en) switching device
DE3603022C2 (en) Piezoelectric relay
DE10239284B4 (en) Electromagnetic relay with non-linear force-displacement behavior of the contact spring and contact spring
EP0375732B1 (en) Locking device for switchgear with electromagnetic drive
DE2848934A1 (en) Miniature electromagnetic relay with armature push-rod - has extension to operate changeover contact spring with long unit on static slot and short moving contact

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): CH DE FR GB LI

17P Request for examination filed

Effective date: 19860728

17Q First examination report despatched

Effective date: 19871023

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB LI

REF Corresponds to:

Ref document number: 3570319

Country of ref document: DE

Date of ref document: 19890622

ET Fr: translation filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19960621

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19960719

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19961017

Year of fee payment: 12

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19970719

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19970731

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19970731

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19970719

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980331

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19980917

Year of fee payment: 14

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000503