DE102011078706B4 - PROCESS AND MANUFACTURING DEVICE FOR PRODUCING A MULTILAYER ACTUATOR - Google Patents

Abstract

Method for producing a multilayer actuator (10), comprising the steps of a) first of all contacting a piezoelectric plate (18, 20) with a surface element (14) having a larger area than the piezoelectric plate (18, 20) and projections (40 ), for producing an actuator assembly (12), wherein the surface element (14) and the piezoelectric plate (18, 20) between a first and a second flexible mounting plate (36, 38) are held without thrust, wherein the surface element (14) Contacting the projections (40) with spacers (42, 46) disposed on the mounting plates (36, 38); b) subsequent bending of the actuator assembly (12); and c) subsequently bonding the piezoelectric plate (18, 20) to the sheet (14), wherein the first and second mounting plates (36, 38) are released from the multi-layer actuator (10) after bonding.

Description

The invention relates to a method for producing a multilayer actuator, in particular Biegeaktuators, and a production apparatus which is suitable for producing a multilayer actuator, in particular Biegeaktuators.

For example, in cramped conditions such as in stator blades of engines, such. As of aircraft, to be able to move small components, actuators are often used in the form of piezoelectric materials. To move the small components of the inverse piezoelectric effect is exploited, in which the piezoelectric material deforms when a voltage is applied, for example, expands or contracts, and so moves the component.

The piezoelectric materials available on the market are mostly ceramics of lead, oxygen, titanium and zirconium, which crystallize in a specific crystal structure. These crystals are mostly brittle and hard and therefore difficult to deform.

Under certain conditions, it may be desirable for the actuator formed of a piezoelectric material to have a curvature. Heretofore, this has been accomplished by adhering a piezoelectric plate to a planar sheet and, after joining the sheet to the sheet, have both been bent together to the desired curvature.

Disadvantage of this method is that on the one hand high mechanical stresses on the surface of the piezoelectric plate arise, which can lead to the destruction of the plate, and further due to the tensile stress occurring due to the subsequent bending only attachment to the concave side of the surface element is possible since the tensile stresses that prevail on the convex side after bending quickly exceed the allowable level.

Another method used in practice is to use instead of piezoelectric plates Piezostreifen that are embedded in a matrix so that they can be deformed about an axis. However, this does not make it possible to achieve a homogeneous area moment of inertia, ie. H. to get a resistance to bending and torsion. Therefore, such piezo stripes embedded in a matrix are rather unsuitable for effecting effective movement of a component.

US 2010/0171395 describes a method of making a multilayer bent actuator wherein a piezoelectric material is attached to a curved surface of a substrate.

In US 5,761,782 For example, a method of manufacturing a bent multilayer actuator is described wherein a folded piezoelectric film is formed between two stamps having curved surfaces.

US Pat. No. 7,084,554 B2 discloses a method of making multilayer actuators wherein the individual layers are bonded together using transfer substrates and then attached to a target substrate.

In US 5,507,896 is a method for producing a multilayer ceramic laminate describe, wherein the layers of the laminate are joined together by applying pressure and temperature. The object of the invention is to provide a curved actuator which provides greater freedom of installation and further provides a homogeneous area moment of inertia.

DE 202 02 297 U1 discloses a flat multilayer component for use as an actuator or sensor, with an electrically activatable material layer, and a passive center layer. Furthermore, a manufacturing method is described.

US Pat. No. 5,632,841 discloses a method of forming ferroelectric wafers. The wafer is placed on a prestressed layer. The layers are heated and cooled, biasing the ferroelectric wafer.

DE 694 10 078 T2 discloses a manufacturing method for an ultrasonic transducer having a matrix of a plurality of acoustically isolated elements evenly distributed along a straight, curvilinear or non-linear axis.

The object of the invention is to provide a curved actuator which provides greater freedom of installation and further provides a homogeneous area moment of inertia.

This object is achieved by a method having the features of claim 1.

A manufacturing device with which such an actuator can be produced is the subject of the independent claim.

Advantageous embodiments of the invention are the subject of the dependent claims.

• a) Zunächst vollflächiges Kontaktieren einer piezoelektrischen Platte mit einem Flächenelement, das eine größere Fläche als die piezoelektrische Platte und Überstände aufweist, zum Erzeugen eines Aktuatoraufbaus, wobei das Flächenelement und die piezoelektrische Platte schubspannungsfrei zwischen einer ersten und einer zweiten biegsamen Montageplatte gehalten werden, wobei das Flächenelement durch Inkontaktbringen der Überstände mit an den Montageplatten angeordneten Abstandshaltern gehalten wird;
• b) Anschließendes Krümmen des Aktuatoraufbaus; und
• c) Anschließendes Verbinden der piezoelektrischen Platte mit dem Flächenelement, wobei die erste und zweite Montageplatte nach dem Verbinden von dem mehrschichtigen Aktuator entfernt werden.

The invention provides a method for producing a multilayer actuator, comprising the steps

• a) First, full surface contacting a piezoelectric plate with a surface element having a larger area than the piezoelectric plate and protrusions, for producing an actuator assembly, wherein the surface element and the piezoelectric plate thrust tension between a first and a second flexible mounting plate are held, said Surface element is held by contacting the supernatants with arranged on the mounting plates spacers;
• b) subsequent bending of the actuator assembly; and
• c) then connecting the piezoelectric plate to the surface element, wherein the first and second mounting plates are removed after the connection of the multi-layer actuator.

In this method, the sensitive piezoelectric plate is thus first brought into contact with the surface element over its entire surface, but not yet connected to it. After contacting the piezoelectric plate with the surface element, both components are curved together and only then firmly connected. Thus, the piezoelectric plate and the surface element can still move against each other during the bending and there are no mechanical stresses caused by a previously made connection. Only when the piezoelectric plate and the surface element are arranged as desired to each other and have the curvature that is desired, the two components are finally connected together. Thus, an actuator, such as in particular a Biegeaktuator, can be achieved, which although by the curvature has a certain bias, but in which the mechanical stresses acting on the actuator, are not so high that it is destroyed. Accordingly, it is also possible to arrange the piezoelectric plate both above the surface element and below the surface element, and to obtain at the end an actuator in which the piezoelectric material is arranged either on the concave or on the convex side of the surface element or on both sides , The curved actuator has a uniform, homogeneous moment of inertia over its entire surface after manufacture by the above method. Thus, after installation, for example in a stator blade of an engine, it can apply a predefined, homogeneous force to the components to be moved over its entire surface.

In the case of a surface element clamped in the edge region, this advantageously acts like the vibrating membrane of a loudspeaker, which can be actuated to generate sound. Suspended in the stator blade of an engine, for example, 110 dB of sound pressure level in the frequency range 1 kHz to 3 kHz can be generated for each actuator. If individual eigenmodes of the actuator in the region of the excitation frequency can advantageously be used, the resonance superelevation can be used to generate a high actuator deflection or a high sound pressure level at a low drive voltage. When using the resonance peak tensile forces usually occur on the Akuatoroberfläche, unless this is additionally biased laterally. Due to the bonding process, however, a thermally induced bias is advantageously possible to compensate for the tensile forces occurring and to avoid destruction of the ceramic.

In step a), the surface element and the piezoelectric plate are clamped free of thrust between a first and a second bendable mounting plate. Thus, prior to curving the actuator assembly, the sheet and the piezoelectric plate may advantageously remain in full contact with one another, but without being firmly joined together. The force of the bendable mounting plates acts only to compress the surface element with the piezoelectric plate, but the two components can advantageously move laterally against each other, so that no tensile or shear stress arises. By using the bendable mounting plates can then be applied over the entire surface of the actuator assembly over the entire surface constant force on the actuator structure advantageous.

The surface element is clamped by bringing its supernatants, in particular outer edge regions, into contact with spacers arranged on the mounting plates. In order to be able to easily install the multilayer actuator at the desired installation site later, the surface element has a larger area than the piezoelectric plate. Accordingly, it preferably overlaps the piezoelectric plate in the actuator structure. In order to avoid a curvature of the overlapping regions of the surface element already when clamping the surface element and the piezoelectric plate between the two mounting plates, spacers are arranged on the mounting plates, which have the same thickness as the piezoelectric plate in a particularly preferred embodiment. Thus advantageously a smaller in size piezoelectric plate can be brought over the entire surface in contact with the surface element and at the same time, the edge regions of the surface element without curvature between the two bendable mounting plates can be clamped.

Preferably flat mounting plates are used so that a good contact with the preferably also flat piezoelectric plate can be produced.

Advantageously, the two mounting plates also have a larger area than the actuator structure. In order to preferably also avoid the bending of the mounting plates when clamping the surface element and the piezoelectric plate between the two mounting plates, spacers are advantageously also provided at the outer edge regions of the mounting plates, which provide the two mounting plates at a distance corresponding to the total thickness of the actuator structure hold. Accordingly, it is particularly preferred if both mounting plates have first spacers which clamp the surface element at its outer edge regions and further second spacers are arranged on the mounting plates, which hold the two mounting plates to each other during clamping at a distance. These second spacers can be provided either on the edge region of one of the two mounting plates or alternately on both mounting plates. Alternatively, second spacers with a thickness which corresponds to half the thickness of the entire actuator structure can also be provided here at the outer edge regions of both mounting plates.

Preferably, for bending in step b), a constant torque is applied over the surface of the actuator assembly. This advantageously results in a bias voltage on the piezoelectric material which has a homogeneous area moment of inertia over the entire area of the piezoelectric material.

Advantageously, a mold with a curved mold surface is used in step b). This advantageously makes it particularly easy to apply a constant torque to the actuator structure.

Preferably, the mold surface of the mold is formed by using at least a first and a second plunger for providing at least two partial mold surfaces. Thus, the actuator assembly can be particularly easily introduced into the mold and then the mold are closed by bringing the two plunger together and thus the Aktuatoraufbau be deformed.

Preferably, a convexly curved part-form surface is provided by the first pressure stamp and a concavely curved part-form surface is provided by the second pressure stamp. Particularly preferably, the partial mold surfaces have the same center of curvature.

If the actuator assembly clamped between the mounting plates is pressed particularly preferably between the two partial mold surfaces in step b), then a force acting perpendicular to the surface of the actuator structure can be produced both from one side via the concavely curved partial mold surface and from the other side via the convexly curved partial mold surface be applied, which bends the actuator assembly.

In a particularly preferred embodiment, sliding surfaces are additionally introduced between the mounting plates and the mold surfaces. Thus, it is possible that the actuator assembly clamped between the mounting plates can also slide back and forth in the lateral direction within the molding tool and thus the application of a tensile or shear stress is advantageously avoided.

Preferably, an adhesive layer is disposed between the piezoelectric plate and the sheet. This adhesive layer may then be advantageously used, after curving the actuator assembly, to interconnect the piezoelectric plate and the sheet. The adhesive layer may, for example, be applied to the piezoelectric plate in the form of an adhesive film on the surface element side.

Advantageously, the adhesive layer is activated and cured by applying temperature in step c) with simultaneous application of the constant moment. As a result, the adhesive layer is advantageously activated only for connecting the piezoelectric plate to the planar element when the actuator structure is already curved. The connection thus takes place in such a way that preferably hardly or no shear stress is applied to the piezoelectric plate. For example, applying an elevated temperature to activate and cure the adhesive layer and thus bond the piezoelectric plate to the sheet may be done simply by heating the mold.

Advantageously, the surface element and the piezoelectric plate have different thermal expansion coefficients. After bending and exposure to temperature as well as connection via the cured adhesive layer, the entire multilayer actuator cools down, the piezoelectric plate and the surface element contracting to different degrees due to the different thermal coefficients. Thus, advantageous over the different Thermal expansion coefficient, a bias of the piezoelectric plate can be achieved on the surface element.

Particularly preferably, a conductive mesh fabric is additionally introduced into the adhesive layer. This is advantageous later better contacting of the piezoelectric plate over the surface element possible.

Preferably, step a) comprises the step of contacting a second piezoelectric plate provided with an adhesive layer with a side of the planar element opposite the first piezoelectric layer. Thus, it is advantageously possible to arrange on both sides of the surface element curved piezoelectric plates and thus to increase the movement distance of the entire multilayer actuator.

Preferably, step a) comprises the step of contacting a third and / or fourth piezoelectric plate with the first and / or second piezoelectric plate. The more piezoelectric plates are arranged in the multilayer actuator, the lower is advantageously the applied electrical voltage required for expansion or contraction of the multilayer actuator. For small radii of curvature, a multilayer actuator is particularly preferred in order to produce the total thickness of the piezoelectric plates desired for the application without exceeding the permissible tensile forces. In addition, it can be advantageously achieved with the arrangement of a plurality of piezoelectric plates, a greater expansion or a larger contraction of the multilayer actuator when subjected to a voltage. This advantageously larger movements of the components to be moved are possible.

Preferably, the sheet, the piezoelectric plates, the mounting plates and the sliding surfaces are arranged to each other so that they can slide against each other during the application of the constant moment orthogonal to the constant moment. Thus, preferably, a tensile or shear stress on all contact surfaces and elements can be avoided.

In a particularly preferred embodiment, a further piezoelectric plate or a membrane, in particular a curved membrane, can be provided as surface element.

• d) Lösen des zweiten Druckstempels bei gleichzeitigem Festhalten der ersten Montageplatte an dem ersten Druckstempel;
• e) Lösen der zweiten Montageplatte;
• f) Entnehmen des gekrümmten, ausgehärteten, mehrschichtigen Biegeaktuators;
• g) Lösen der ersten Montageplatte von dem ersten Druckstempel.

After the adhesive layer has cured, the following steps for removing the multilayer actuator from the mold are advantageously carried out in order to advantageously avoid damage to the multilayer actuator:

• d) releasing the second plunger while holding the first mounting plate to the first plunger;
• e) releasing the second mounting plate;
• f) removing the curved, cured, multilayer bending actuator;
• g) releasing the first mounting plate from the first plunger.

Thus, advantageously, even after curvature of the actuator assembly, the application of a negative tensile or shear stress can be avoided.

A production apparatus for producing a multilayer actuator, in particular a multilayer bending actuator, comprises a handling device for contacting a piezoelectric plate over the entire surface with a surface element for producing an actuator assembly, wherein as handling means a first and a second flexible mounting plate are provided which have spacers and which are formed between them to hold the surface element and the piezoelectric plate thrust-free, wherein the mounting plates are further adapted to hold the surface element by means of the spacers on a projection of the surface element, a curving device for curving the Aktuatoraufbaus and connecting means for connecting the piezoelectric plate with the surface element on.

Advantageously, the two mounting plates on their outer wall areas arranged first spacers and / or second spacers in order to clamp the surface element at its outer edge regions and to keep each other at a distance.

In order to advantageously be able to apply a constant torque over the surface of the actuator assembly, the bending device is formed by a molding tool with a curved mold surface. For this purpose, the bending device particularly preferably has a first and a second pressure stamp. The first pressure stamp preferably has a convexly curved partial mold surface and the second pressure stamp preferably has a concavely curved partial mold surface. Furthermore, the bending device preferably comprises sliding surfaces to be introduced between the mounting plates and the mold surfaces.

The connecting device is preferably formed by an adhesive layer, which can be activated and cured by a temperature application. Furthermore, the adhesive layer advantageously has a conductive mesh.

An advantageous embodiment of the invention will be explained in more detail with reference to the accompanying drawings. It shows:

1 Individual parts for producing a multilayer actuator;

2 a first step of manufacturing the multilayer actuator;

3 a second step of manufacturing a multi-layered actuator;

4 a third step of manufacturing the multilayer actuator;

5 a first step of removing the finished curved multilayer actuator;

6 a second step of removing the finished curved multilayer actuator;

7 a third step of removing the finished curved multilayer actuator; and

8th the finished curved actuator.

1 shows the items that are needed to a shear stress-free multi-layer actuator, in particular a multi-layer bending actuator 10 , to build.

For generating an actuator structure 12 becomes a surface element in the embodiment shown 14 in the form of a curved membrane 16 and a first piezoelectric plate 18 and a second piezoelectric plate 20 used.

In the illustrated embodiment, the first piezoelectric plate is 18 on a first page 26 of the surface element 14 , on a concave side 28 arranged. The second piezoelectric plate 20 is on one of the first page 26 opposite second side 22 of the surface element 14 namely a convex side 24 arranged.

Surface element side, the two piezoelectric plates 18 . 20 one adhesive layer each 30 in the form of a not yet active adhesive film 32 as a connection device 33 on. In the adhesive film 32 introduced is a not shown conductive mesh.

The piezoelectric plates 18 . 20 and the surface element 14 shall now over the entire surface of the piezoelectric plates 18 . 20 be brought into contact with each other. These are handling equipment 34 in the form of a first mounting plate 36 and a second mounting plate 38 intended. The mounting plates 36 . 38 are made of bendable material.

The first mounting plate 36 is from the surface element 14 seen from behind the first piezoelectric plate 18 to arrange. The second mounting plate 38 on the other hand, behind the second piezoelectric plate 20 to arrange. So can by compressing the mounting plates 36 . 38 the two piezoelectric plates 18 . 20 with the surface element 14 be brought into contact over the entire area.

The surface element 14 has a larger area than the piezoelectric plates 18 . 20 on. The piezoelectric plates 18 . 20 are in the middle of the first page 26 or the second page 22 of the surface element 14 arranged. So that the surface element 14 when pressing the mounting plates 36 . 38 despite his supernatants 40 over the piezoelectric plates 18 . 20 not with one or both of the supernatants 40 undesirable in one direction, but by the compression of the mounting plates 36 . 38 is leveled, assign the mounting plates 36 . 38 at her to the surface element 14 to be straightened pages first spacers 42 on. When pressing the mounting plates 36 . 38 become outer edge areas 44 of the surface element 14 between the first spacers 42 held so that the surface element 14 by compressing the mounting plates 36 . 38 can be leveled.

Next point the mounting plates 36 . 38 to the first spacers 42 further outwardly arranged second spacers 46 on that make sure the mounting plates 36 . 38 during compression of the piezoelectric plates 18 . 20 and the surface element 14 just remain. So that only small forces through the first and second spacers 42 . 46 act and the surface element 14 despite the solid cohesion of the mounting plates 36 . 38 can still slide in a lateral direction, the spacers 42 . 46 Made of fabric tape.

To the actuator structure 12 to be able to bend, is a Krümmeinrichtung 48 in the form of a mold 50 with a curved mold surface 52 intended. The curved shape surface 52 is doing by a first plunger 54 and a second plunger 56 formed, thus forming a first Teilformoberfläche 58 and a second part mold surface 60 provide.

The first part form surface 58 is convexly curved and the second Teilformoberfläche 60 is concavely curved. The second part form surface 60 points next to its concave curvature area parallel to the mounting plates 36 . 38 disposed surfaces 62 on, over which the mounting plates 36 . 38 as well as the interposed actuator assembly 12 in the mold 50 can be fixed.

Between the part form surfaces 58 . 60 and the mounting plates 36 . 38 are still made of Teflon sliding surfaces 64 provided by the mounting plates 36 . 38 in the lateral direction in the mold 50 can slide.

The formation of the multilayer bending actuator 10 is now in the 2 to 4 shown.

In 2 is a first step in forming the actuator assembly 12 shown. These are the surface element 14 , the piezoelectric plates 18 . 20 as well as the mounting plates 36 . 38 as in 1 shown arranged to each other and then the mounting plates 36 . 38 in the in 2 shown arrow direction moved towards each other. The mounting plates are pressed 36 . 38 on the surfaces of the piezoelectric plates 18 . 20 , At the same time, the surface element becomes 14 about the first spacers 42 held and leveled by the contact pressure, so that it no longer has a curvature. This will cause the piezoelectric plates 18 . 20 and the surface element 14 over the entire surface in contact with each other, wherein between the piezoelectric plates 18 . 20 and the surface element 14 the adhesive film 32 is arranged, which later the connecting device 33 forms. In the lateral direction are the piezoelectric plates 18 . 20 and the surface element 14 still mobile.

In a second step for the production of the multilayer bending actuator 10 , shown in 3 , now becomes the actuator structure 12 with the mounting plates 36 . 38 between the stamps 54 . 56 fixed, with the sliding surfaces 64 to the pressure-stamp side of the mounting plates 36 . 38 be pressed. The fixation takes place over the surface 62 the second part form surface 60 as well as a top point 68 the first part form surface 58 ,

In a third step for producing the multilayer bending actuator 10 , shown in 4 , now the parts mentioned are firmly between the two stamps 54 . 56 Pressed together by the plunger 54 . 56 to be brought together on strike. The actuator assembly rolls on the first part mold surface 58 and forms the desired curvature, through the second Teilformoberfläche 60 is kept stable. It can be seen that all in the mold 50 introduced elements are laterally movable relative to each other, in particular this is based on the compared to 2 shifted spacers 42 . 46 seen. By compressing the two plungers 54 . 56 will be in the in 4 arrow direction shown a constant moment on the actuator structure 12 applied.

While the two printing stamps 54 . 56 the actuator structure 12 with the mounting plates 36 . 38 and the sliding surfaces 64 hold in the curvature shown, ie while the constant moment is applied to it, the mold becomes 50 subjected to an elevated temperature, wherein the adhesive layer 30 activated and cured at the same time. In this case, the piezoelectric plates connect 18 . 20 and the surface element 14 firm and inseparable from each other. A lateral displacement of the piezoelectric plates 18 . 20 as well as the surface element 14 is already compressing the plunger 54 . 56 takes place, so that when gluing the piezoelectric plates 18 . 20 with the surface element 14 no tensile or shear stresses occur anymore. The surface element 14 has a different thermal expansion coefficient than the piezoelectric plates 18 . 20 so that the elements contract differently when cooling down. Thereby the piezoelectric plates become 18 . 20 even more laterally compressed and thus biased. In operation, the risk of tensile forces is minimized, even in the case of resonance peaks.

To the finished multilayer bending actuator 10 also shear stress free from the mold 50 to be able to remove, as in 5 shown, first the second plunger 56 solved, with the first mounting plate 36 with the multilayer bending actuator resting thereon 10 at the first printing stamp 54 is held (arrow position shown).

After that, as in 6 shown, the cooled multilayer bending actuator 10 away. The first mounting plate 36 will continue at the arrow positions shown on the first plunger 54 recorded. So no unwanted force by jumping back the bendable first mounting plate 36 on the multilayer bending actuator 10 be applied.

Only after the multilayer bending actuator 10 from the mold 50 is removed, too, as in 7 shown the first mounting plate 36 from the first printing stamp 54 solved.

It results in the 8th shown multilayer bending actuator 10 that between two now curved piezoelectric plates 18 . 20 the curved membrane 16 having, via the connecting device 33 in the form of the activated adhesive layer 30 firm and unsolvable with the piezoelectric plates 18 . 20 connected is.

With the method shown above, it is possible to have commercially available planar piezoelectric plates 18 . 20 on both sides under defined flat pretensioning on a curved membrane 16 attach to a multilayer bending actuator 10 to obtain. The multilayer bending actuator 10 has a very long life due to its construction.

This multilayer bending actuator 10 can be preferably used in tight installation conditions that require a flat and curved actuator geometry, such as in stator blades of engines.

To planar piezoelectric plates 18 . 20 curved surfaces, such as a curved membrane 16 , To attach, so far the zugempfindliche ceramic on a flat surface element 14 glued and then curved. However, this results in high mechanical stresses on the ceramic surface. This method can also only on the concave side 24 the curved membrane 16 be applied because on the convex side 28 the tensile stresses quickly exceed the permissible level.

Another method is to use piezoelectric plates instead 18 . 20 to use piezo stripes embedded in a matrix (available from, for example, Mide Technology Corporation), which are then deformable about an axis. However, this gives an inhomogeneous area moment of inertia.

The process takes place in several steps with the aid of a production device 70 that allows the piezoelectric plates 18 . 20 in its original flat form to an originally pre-curved membrane 16 with intermediate adhesive film 32 to press flat. This is defined by means of two flexibly flexible mounting plates 36 . 38 reached, which is the curved membrane 16 deform such that it is flat against the piezoelectric plates 18 . 20 is applied. Subsequently, as in a 4-point bending test, the entire assembly is subjected to a constant external moment and thus almost constant to the predetermined shape, the stop, curved. It is possible that the bearing surfaces can slide away from each other almost free of tension. Finally, the temperature is applied to the adhesive layer 30 cured and also the piezoelectric plates 18 . 20 exclusively biased by the different thermal expansion coefficients and the set curing temperature defined.

In the adhesive film 32 can be embedded for better contacting a conductive mesh.

The method allows piezoelectric plates 18 . 20 Any manufacturer on both sides of a curved membrane 16 under mechanical pretension to induce homogeneous actuator deformation. With the design freedom thus obtained, a significant electromechanical increase in efficiency is achieved.

One in the adhesive film 32 embedded conductive mesh ensures a reliable surface contact of the piezoelectric plates 18 . 20 , Thus, the multilayer bending actuator 10 be used in case of occurring mechanical overloading and associated cracking in the ceramic without significant losses in the actuator performance and life.

• • Piezoelektrische Platte 18 – gekrümmte Membran 16 – piezoelektrische Platte 20
• • Piezoelektrische Platte 18 – piezoelektrische Platte 20 (ohne gekrümmte Membran 16)
• • Piezoelektrische Platte 18 – piezoelektrische Platte 18 – gekrümmte Membran 16 – piezoelektrische Platte 20 – piezoelektrische Membran 20
• • Piezoelektrische Platte 18 – gekrümmte Membran 16 (als asymmetrischer Aufbau)

With the method, it is possible to use the following construction variants of a multilayer actuator, in particular a multilayer bending actuator 10 to manufacture:

• • Piezoelectric plate 18 - curved membrane 16 - piezoelectric plate 20
• • Piezoelectric plate 18 - piezoelectric plate 20 (without curved membrane 16 )
• • Piezoelectric plate 18 - piezoelectric plate 18 - curved membrane 16 - piezoelectric plate 20 - piezoelectric membrane 20
• • Piezoelectric plate 18 - curved membrane 16 (as asymmetrical structure)

Such multilayer actuators, in particular multilayer bending actuators, z. B. in engine blades of, for example, aircraft, especially in turbine blades in turbines of aircraft and / or jackscrews are used.

LIST OF REFERENCE NUMBERS

10

multilayer bending actuator

12

actuator assembly

14

surface element

16

curved membrane

18

first piezoelectric plate

20

second piezoelectric plate

22

second page

24

convex side

26

first page

28

concave side

30

adhesive layer

32

adhesive film

33

connecting device

34

handling device

36

first mounting plate

38

second mounting plate

40

Got over

42

first spacer

44

outer edge area

46

second spacer

48

Krümmeinrichtung

50

mold

52

curved mold surface

54

first printing stamp

56

second printing stamp

58

first part form surface

60

second part form surface

62

area

64

sliding surfaces

68

top point

70

making device

Claims (13)

Method for producing a multilayer actuator ( 10 ), with the steps a) First, full-surface contacting a piezoelectric plate ( 18 . 20 ) with a surface element ( 14 ), which has a larger area than the piezoelectric plate ( 18 . 20 ) and supernatants ( 40 ) for generating an actuator structure ( 12 ), wherein the surface element ( 14 ) and the piezoelectric plate ( 18 . 20 ) Schubspannungsfrei between a first and a second flexible mounting plate ( 36 . 38 ), wherein the surface element ( 14 ) by contacting the supernatants ( 40 ) with at the mounting plates ( 36 . 38 ) arranged spacers ( 42 . 46 ) is held; b) subsequent bending of the actuator assembly ( 12 ); and c) subsequently connecting the piezoelectric plate ( 18 . 20 ) with the surface element ( 14 ), wherein the first and second mounting plates ( 36 . 38 ) after joining the multilayer actuator ( 10 ) are solved. Method according to one of the preceding claims, characterized in that for bending in step b) an over a surface ( 62 ) of the actuator assembly ( 12 ) constant moment is applied. Method according to one of the preceding claims, characterized in that in step b) a mold ( 50 ) having a curved molding surface ( 52 ) is used. Method according to claim 3, characterized in that the mold surface ( 52 ) by using at least a first and a second plunger ( 54 . 56 ) for providing at least two partial shaping surfaces ( 58 . 60 ) is formed. A method according to claim 4, characterized in that by the first plunger ( 54 ) a convexly curved partial surface ( 58 ) and by the second plunger ( 56 ) a concavely curved partial surface ( 60 ) is made available. Method according to one of claims 4 or 5, characterized in that in step b) the between the mounting plates ( 36 . 38 ) clamped actuator assembly ( 12 ) between the part form surfaces ( 58 . 60 ) and / or that between the mounting plates ( 36 . 38 ) and the partial form surfaces ( 58 . 60 ) Sliding surfaces ( 64 ) are introduced. Method according to one of the preceding claims, characterized in that between the piezoelectric plate ( 18 . 20 ) and the surface element ( 14 ) an adhesive layer ( 30 ) is arranged. A method according to claim 7, characterized in that in step c) while simultaneously applying the constant moment, the adhesive layer ( 30 ) is activated by temperature and hardened. A method according to claim 7 or 8, characterized by introducing a conductive mesh fabric into the adhesive layer ( 30 ). Method according to one of the preceding claims, characterized in that step a) comprises the step of contacting an adhesive layer ( 30 ) second piezoelectric plate ( 20 ) with one of the first piezoelectric plate ( 18 ) opposite side of the surface element ( 14 ) and / or the step of contacting a third and / or fourth piezoelectric plate with the first and / or second piezoelectric plate ( 18 . 20 ). Method according to one of the preceding claims, characterized in that the surface element ( 14 ), the piezoelectric plates ( 18 . 20 ), the mounting plates ( 36 . 38 ) and the sliding surfaces ( 64 ) are arranged to each other so that they can slide against each other during the application of the constant torque orthogonal to the constant moment. Method according to one of the preceding claims, characterized in that as surface element ( 14 ) another piezoelectric plate or a membrane ( 16 ) provided. Manufacturing device ( 70 ) for producing a multilayer actuator ( 10 ), with a handling device ( 34 ) for full surface contacting of a piezoelectric plate ( 18 . 20 ) with a surface element ( 14 ) for producing an actuator structure ( 12 ), as a handling device ( 34 ) a first and a second flexible mounting plate ( 36 . 38 ), the spacers ( 42 . 46 ) and which are formed, between them the surface element ( 14 ) and the piezoelectric plate ( 18 . 20 ) shear stress-free, the mounting plates ( 36 . 38 ) are further formed, the surface element ( 14 ) by means of the spacers ( 42 . 46 ) on a supernatant ( 40 ) of the surface element ( 14 ), a curving device ( 48 ) for curving the actuator assembly ( 12 ) and with a connection device ( 33 ) for connecting the piezoelectric plate ( 18 . 20 ) with the surface element ( 14 ).

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