The invention relates to a method for operating an electromechanical element, an actor, a drive device with an actor and a motor with a drive device and an element to be driven.
JP 2012 147510 A discloses a drive device with a stationary mounted first actor and a second actor which is located on the first actor and is provided for contact with an element to be driven. The deformation directions of the two actors are perpendicular to one another. The first actor is subjected to a symmetrical triangle voltage. In the increasing or decreasing range, the second actor is subjected to a high-frequency voltage in order to be able to effect with the vibrations which are generated thereby in the second actor or at the interface between the second actor and the element to be driven in this time range a reduction of the friction coefficients between the second actor and the element to be driven, so that a sliding relative movement between the second actor and the element to be driven can be realized in the relevant time range (slip phase), while in the respective other time range of the triangle voltage in which the high-frequency voltage is not applied to the second actor, the coefficient of friction between the second actor and the element to be driven is not reduced and is dimensioned such that due to the prevailing friction (i.e. static friction) the element to be driven follows the movement of the second actor caused by the first actor (stick phase).
The object of the invention is to provide a method for operating an electromechanical element, an actor, a drive device with such an actor and a motor with such a drive device, with which an element to be driven can be positioned with a predetermined accuracy.
This object is achieved with the features of the independent claims. Further embodiments are specified in the subclaims that refer back to these in each case.
According to the invention, a method is provided which comprises the following steps:
by controlling a first control section which is deformable by an electrical voltage with a first voltage signal generation of adjusting movements of a friction element which is arranged on the electromechanical element and which is provided for frictional contact with an element to be driven, wherein the first voltage signal comprises a plurality of signal flanks which rise according to absolute amount and signal flanks which decrease according to absolute amount over time, wherein the increasing signal flanks and the decreasing signal flanks which alternate with each other in terms of time, wherein after an increasing signal flank and before a subsequent decreasing signal flank, or vice versa, an intermediate signal section with a non-zero time interval which differs over time from the shape of the signal flanks and preferably comprise a time-dependent gradient,
controlling of a second control section which is deformable by an electrical voltage with a second voltage signal, which comprises a signal section, the frequency of which compared to the first voltage signal is by a factor of at least 10 higher and begins in terms of time within the time interval tz of a signal intermediate section of the first voltage signal and extends at least partially over the signal flank which in terms of time follows the signal intermediate section.
In particular, the invention relates to a method for operating an electromechanical element or an actor.
In the embodiments of the method according to the invention, it can be provided that the signal intermediate section comprises a time-dependent gradient, which amounts to a maximum of 10 degrees.
In the embodiments of the method according to the invention, it can be provided that the signal section of the second voltage signal begins after at least 10% and at most 90% of the time interval tz of the signal intermediate section has elapsed or 50% of the time interval before the end of the same.
In the embodiments of the method according to the invention, it can be provided that the signal segment of the second voltage signal extends into an adjacent and temporally subsequent intermediate section and within its time interval tz or ends until its end.
In the embodiments of the method according to the invention, it can be provided that the signal section of the second voltage signal is sinusoidal.
In the embodiments of the method according to the invention, it can be provided that the maximum amplitude of the signal section of the second voltage signal is at most 50% of the maximum amplitude of the first voltage signal.
In the embodiments of the method according to the invention, it can be provided
that the control of the first control section is a simultaneous control of a plurality of first control sub-sections with the first voltage signal, wherein the first control sub-sections form the first control section and are located one behind the other in the longitudinal direction,
that the control of the second control section is a simultaneous control of several second control sub-sections with the second voltage signal, wherein the second control sub-sections form the second control section and are located one behind the other in the longitudinal direction.
In the embodiments of the method according to the invention, it can be provided that, simultaneously with the control of the first control section, a third control section which is deformable by an electrical voltage is controlled with the first voltage signal, wherein the third control section is arranged such that the second control section is located between the first and the third control section.
In the embodiments of the method according to the invention, it can be provided that the control of the third control section is a simultaneous control of a plurality of third control sub-sections with the first voltage signal, wherein the third control sub-sections form the third control section and are located one behind the other in the longitudinal direction.
According to the invention, an actor is provided which comprises:
a first control section which extends in a longitudinal direction and is deformable by an electrical voltage and comprises: a first deformation body, which is delimited by a first outer surface and two end faces which are lying opposite to each other, between which the first outer surface extends along the longitudinal direction, and two actuation electrodes which extend transversely to the longitudinal direction electrodes, wherein one actuation electrode acts as an excitation electrode and is disposed at the first end face and wherein another actuation electrode acts as a common electrode and is disposed at the second end face,
a second control section which extends in a longitudinal direction and is deformable by an electrical voltage and comprises: a second deformation body, which is disposed in the longitudinal direction at the first deformation body, wherein the second deformation body is delimited by a second outer surface and two end faces which are lying opposite to each other, between which the first outer surface extends along the longitudinal direction, and two actuation electrodes which extend transversely to the longitudinal direction electrodes, wherein one actuation electrode acts as an excitation electrode and is disposed at the first end face and wherein another actuation electrode acts as a common electrode and is disposed at the second end face,
a first control electrode which is disposed at a first connection section of the first outer surface and which is electrically connected to the excitation electrode of the first control section,
a second control electrode which is electrically separated from the first control electrode, which is disposed at a second connection section of the second outer surface and which is electrically connected to the excitation electrode of the second control section,
a reference electrode which is disposed at the first outer surface and the second outer surface and separated from the first control electrode and separated from the second control electrode and which is electrically connected to the common electrodes of the first and the second deformation body.
The actor according to the invention is particularly suitable for using an embodiment of the method according to the invention. It can also be provided that the actor is realized to carry out the method according to the invention.
In the embodiments of the actor according to the invention, it can be provided that the actor furthermore comprises:
a third control section which extends in a longitudinal direction and is deformable by an electrical voltage and which is located at a side of the second control section, wherein this side is located opposite of the side of the first control section with respect to the longitudinal direction, and wherein the third control section comprises:
a third deformation body, which is delimited by a third outer surface and two end faces which are lying opposite to each other, between which the third outer surface extends along the longitudinal direction, and two actuation electrodes which extend transversely to the longitudinal direction, wherein one actuation electrode acts as an excitation electrode and is disposed at the first end face and wherein another actuation electrode acts as a common electrode and is disposed at the second end face, and
a third control electrode which is disposed at a third outer surface of the third connection section of the is arranged and which is electrically connected to the excitation electrode of the third control section,
wherein the reference electrode is additionally disposed at the third outer surface of the third deformation body and separated from the third control electrode and separated from the second control electrode and which is electrically connected to the common electrode of the third deformation body.
In the embodiments of the actor according to the invention, the third control electrode can be formed in one piece with the first control electrode.
In the embodiments of the actor according to the invention, at least one of the control sections can be formed of a sequence of several control sub-sections, wherein each of the control sub-sections is formed of a plate-shaped excitation electrode which extends transversely to the longitudinal direction, of a plate-shaped common electrode which extends transversely to the longitudinal direction and of a layer which is located between these in the longitudinal direction and is made of an electromechanical, in particular piezoelectric material, wherein the layer (P) is respectively located between the excitation electrode and the common electrode.
In the embodiments of the actor according to the invention, at least one of the deformation bodies can be formed from a homogeneous and electrically deformable material.
In the embodiments of the actor according to the invention, a friction element can be arranged on an end section of the first control section or of the second control section oriented in the longitudinal direction.
According to the invention, a drive device with an embodiment of the actor according to the invention and with a holding device is provided, wherein the holding device is formed in an at least partially elastic manner, wherein the actor is held in the holding device and preferably clamped therein.
In the embodiments of the drive device according to the invention, the holding device can be realized as a tensioning frame surrounding the actor at least in sections.
According to the invention, a motor with a drive device according to an embodiment of the invention and with an element to be driven is provided, which is supported so as to be movable relative to the drive device and which is in frictional contact with a friction element which is disposed at the actor.
The invention is described below with reference to the accompanying figures, wherein:
The actor 1 according to the invention is formed from a group of at least two control sections A1 and A2, which each extend in a longitudinal direction L of the actor 1 and, viewed in the longitudinal direction L, are arranged one behind the other. The actor 1 is as realized as an electromechanical and preferably a piezoelectric element. The actor 1 is delimited by an outer actor outer surface FA and two actor end faces FE1, FE2 which are oriented opposite to each other with respect to the longitudinal direction L and between which the actor outer surface FA extends along the longitudinal direction L.
The first control section A1 comprises a first deformation body D1, which is delimited by a first outer surface 10 and two end faces 11, 12 which are oriented opposite one another with respect to the longitudinal direction L and between which the first outer surface 10 extends along the longitudinal direction L, and at least two actuation electrodes E1, E2 which extend transversely to the longitudinal direction L. The end faces 11, 12 which are formed in the longitudinal direction L comprise a first end face 11 as an actor end face FE1 and a second end face 12. In a functional aspect, based on the control function according to the invention, a first actuation electrode of the actuation electrodes E1, E2 is disposed as an excitation electrode E1 at the first end face 11 and at least one common electrode E2 is disposed at a second end face 12. Within the first deformation body D1, further actuation electrodes E1, E2, which extend transversely to the longitudinal direction and which are disposed in a distance from one another and between which electromechanical material is located can be arranged in order to realize a multilayer structure. In this case, due to the control provided according to the invention, an excitation electrode E1 and a common electrode E2 can be arranged at least in sections alternately, viewed in the longitudinal direction L, when starting from the first end face 11 to the second end face 12. In the embodiments described herein with a first end face 11, the same can be realized as a first actor end face FE1.
The second control section A2 comprises a second deformation body D2, which is delimited by a second outer surface 20 and two end faces 21, 22 which are oriented opposite to one another in relation to the longitudinal direction L and between which the second outer surface 20 extends along the longitudinal direction L, and at least two actuation electrodes E1, E2 which extend transversely to the longitudinal direction L. The end faces 21, 22 comprise a first end face 21 and a second end face 22 as an actor end face FE2. As with the first control section A1, in a functional aspect, based on the control function according to the invention, from the group of actuation electrodes E1, E2 a first electrode E1 with the function of an excitation electrode is disposed at the first end face 21 and at least one common electrode E2 is disposed at a second end face 22. Within the second deformation body D2, further actuation electrodes E1, E2 which extend transversely to the longitudinal direction and are spaced apart from each other, and intervening layers of electromechanical material, each of which lie between them in each case, may be arranged for realizing a multilayer structure. In this case, due to the control provided according to the invention an excitation electrode E1 and a common electrode E2 can be arranged at least in sections alternately, viewed in the longitudinal direction L, when starting from the first end face 11 to the second end face 12. The actor 1 with the two control sections A1, A2 extends in the longitudinal direction L between the end faces 11, 22, which form the actor end faces FE1 and FE1, respectively.
The actor 1 of
The actor 1 further comprises a reference electrode 5, which is disposed on the first outer surface 10 of the first deformation body D1 and the second outer surface 20 of the second deformation body D2 and which extends at least partially over both outer surfaces 10, 20 or essentially over both outer surfaces 10, 20. The reference electrode 5 is therefore an external electrode with respect to the control sections A1, A2. The reference electrode 5 is electrically separated from the first control electrode 15 and of the second control electrode 25 and is electrically connected to the at least one common electrode E2 of the first and second deformation bodies D1 and D2.
Embodiments of the invention may comprise a friction element F, which is disposed at an actuation surface 1a which is oriented in the longitudinal direction L and which takes over the deformation movements of the first end face 11 of the actor 1 and transfers them to the friction element F.
For the embodiments of the actor 1 that can be taken from
In the embodiment of
In the embodiments according to
In this embodiment, the actor 1 additionally comprises a third control section A3 which extends in a longitudinal direction and which is deformable by an electrical voltage, wherein the second control section A2 is located between the first control section A1 and the third control section A3, so that the control sections A1, A2 and A3 are located one behind the other as seen in the longitudinal direction L. The third control section A3 comprises: a third deformation body D3, which is delimited by a third outer surface 30, and by a first end face 31 and by a second end face 32 as a second actor end face FE2, which is positioned opposite to the first end face 31 with respect to the longitudinal direction L, and by at least two actuation electrodes E1, E2 which extend transversely to the longitudinal direction. The third outer surface 30 extends between the end faces 31, 32 along the longitudinal direction L. The actuation electrodes E1, E2 are realized, due to the control provided according to the invention, by at least one excitation electrode E1, which is disposed on the first end face 31, and at least one common electrode E2, which is disposed on the second end face 32. Within the third deformation body D3, further actuation electrodes E1, E2, which extend transversely to the longitudinal direction and which are disposed in a distance from one another with a layer made of an electromechanical material located between the same in each case can be arranged in order to realize a multilayer structure. In this case, due to the control provided according to the invention, an excitation electrode E1 and a common electrode E2 can be disposed at least in sections alternately, viewed in the longitudinal direction L, when starting from the first end face 11 to the second end face 12.
The embodiment of the actor 1 according to
The third drive electrode 35 can be electrically connected to the first control electrode 15. For this purpose, this electrical connection can be realized with external lines. As an alternative or in addition, as provided in the embodiment of the actor 1 according to
The reference electrode 5 is disposed electrically separated from the first, second and third control electrode 15, 25, 35 and electrically connected to the at least one common electrode E2 of the first deformation body D1 and of the second deformation body D2 and of the third deformation body D3. In the embodiment of the actor 1 according to
In particular, the first control electrode 15, the second control electrode 25, the third control electrode 35 and the reference electrode 5, or one or more of these electrodes, may be realized as a layer applied to the respective outer surface or respective outer surfaces or as a flexible plate or be realized as an inflexible plate.
The actor 1 with the three control sections A1, A2, A3 extends in the longitudinal direction L between the end faces 11, 32, which form the actor end faces FE1 and FE1, respectively.
According to one embodiment of the actor 1, the first deformation body D1, the second deformation body D2 and the third deformation body D3 or one or more of these deformation bodies are each made of a homogeneous and electrically deformable material, i.e. formed as a bulk and formed without comprising a multilayer structure. A control section with such a deformation body formed as a bulk comprises at least two actuation electrodes E1, E2, which are formed in particular respectively on one of two end faces of the respective deformation body which are located opposite one another in the longitudinal direction L. One or both of the electrodes can also be arranged within the bulk and at a distance from one another in the longitudinal direction L.
An example of an embodiment in which three deformation bodies D1, D2 and D3 of the actor 1 are each realized as a bulk is shown in
As an alternative or in addition to this, in the actor 1 according to the invention, one of its control section or several of its control sections can be formed from several control subsections, each of which extend transversely to the longitudinal direction L and are located in layers on top of one another in the longitudinal direction L. Each control section is formed of a plate-shaped actuation electrode which extends transversely to the longitudinal direction with the function of an excitation electrode, of a plate-shaped actuation electrode which extends transversely to the longitudinal direction with the function of a common electrode and of a piezoelectric layer which is located in the longitudinal direction between these actuation electrodes, wherein the piezoelectric layer is electromechanically deformable.
the first control section A1 comprises the control subsections A11, A12, A13 with the piezoelectric layers P11, P12, P13,
the second control section A2 comprises the control sections A21, A22, A23, A24 with the piezoelectric layers P21, P22, P23, P24, and
the third control section A3 comprises the control sections A31, A32, A33, A34 with the piezoelectric layers P31, P32, P33, P34.
Each piezoelectric layer of a control subsection A1, A2, A3 comprises subsection end faces F1, F2 which are located opposite to one another and which extend transversely to the longitudinal direction L and which are oriented opposite to one another in relation to the longitudinal direction L. An actuation electrode E1, E2 is located on each subsection end face F1, F2. The same may have the shape of a plate or of a layer, or may have another shape, and for example may be formed as a wire section. Between two control sections of a control subsection A1, A2, A3 also a material layer can be located which is not electromechanically deformable.
As an example with the reference numerals of
(a) the first control section A1 is formed of a sequence of several first control subsections A11, A12, A13 each with a plate-shaped excitation electrode which extends transversely to the longitudinal direction, with a plate-shaped common electrode which extends transversely to the longitudinal direction and a piezoelectric layer which is located between each two internal electrodes in the longitudinal direction;
(b) the second control section A2 is formed of a sequence of several second control subsections A21, A22, A23, A24 each with a plate-shaped excitation electrode which extends transversely to the longitudinal direction, with a plate-shaped common electrode which extends transversely to the longitudinal direction and a piezoelectric layer which is located between each two internal electrodes in the longitudinal direction;
(c) the third control section A3 is formed of a sequence of several third control subsections A31, A32, A33 each with a plate-shaped excitation electrode which extends transversely to the longitudinal direction, with a plate-shaped common electrode which extends transversely to the longitudinal direction and a piezoelectric layer which is located between each two internal electrodes in the longitudinal direction.
In this case, the control section or the control sections which are not formed according to (a), (b) or (c) may be formed in bulk construction.
The actor 1 according to the invention can also be realized by combinations of alternatives (a), (b), (c) with features or embodiments which are described with reference to
The actor 1 may be coated in sections or completely on its outside. In the actor 1 which is realized according to the invention, for example with at least two control sections A1 and A2, by a corresponding control with voltage signals, which are generated by the signal generating device V and which are acting respectively between the actuation electrodes E1, E2 lying adjacent in the longitudinal direction L, the deformation states shown in
The actuation electrodes E1, E2 can be realized in various manners in the embodiments of the actor 1 mentioned herein and also in control sections thereof. For example, the actuation electrodes E1, E2 can be shaped as a plate, layered, shaped as a line section or shaped as material patches.
According to the invention, the actor 1 may be held in a holding device 40 and preferably may be structurally integrated therein, so that the actor 1 together with the holding device 40 forms a drive device K. The holding device 40 may be realized as a tensioning frame 41 which, at least in sections, is made of an elastic material is formed, in which the control sections of the respective actor 1 are resiliently clamped. The clamping force or the compression force which the holding device 40 exerts on the actor 1 acts in the longitudinal direction L of the actor 1 in order to preload the actor 1 in this direction. In this way, the actor is under compressive stress and is thus returned more quickly from an expanded state to a contracted state. The holding device 40 is preferably realized such that it extends at least on one side of the actor 1 over a distance running from the first actor end face FE of the actor 1 to the second actor end face FE2 of the same and thus that the same surrounds or embraces or clasps the actor 1 at least in sections in the longitudinal direction L.
According to the invention, a method for operating an actor 1 and preferably an actor according to the above description with at least two control sections A1, A2, which are arranged one behind the other in a longitudinal direction L of the actor 1, is provided. Furthermore, according to the invention, a method for operating a drive device K, which comprises an actor 1 according to the invention and a friction element F which is arranged on an actuation surface 1a, is provided. The friction element F can be disposed directly or indirectly, for example via an intermediate layer or structural component lying in between, on the first end face 11 of the actor 1, so that deformation movements of the actor 1 cause corresponding changes in position and orientation of the friction element F. The deformation movements of the actor 1 cause changes in position of the actuation area 1a at the position of the friction element F, which for example are shown in
In particular, the actor according to one of the embodiments described herein is formed with at least a first control section which is deformable by an electrical voltage with a first end face 11 and a second control section which is deformable by an electrical voltage with a further end face, which is oriented opposite to the first end face 11. According to the invention, a friction element F for formation of the drive device K may be located on the first end face 11 or the further end face.
In this case a first control section A1, which is deformable by an electrical voltage, is controlled with a first voltage signal S10 and, superimposed in time segments, a second control section A2, which is deformable by an electrical voltage, is controlled with a second voltage signal S20.
The first voltage signal S10 comprises a signal which is formed of: a plurality of signal sections or signal flanks S11 which increase according to absolute amount, a plurality of signal sections or signal flanks S12 which decrease according to absolute amount and a plurality of intermediate signal sections S13, each of which is positioned between one signal flank S11, which increases according to absolute amount, and one signal flank S12, which decreases according to absolute amount. The signal intermediate sections S13 extend over a time interval tz which differs from zero, or, to put it another way: the time interval tz extends over a time period which comprises the amount of which is not equal to zero.
The first voltage signal S10 comprises signal flanks which are increasing according to absolute amount and signal flanks which are decreasing according to absolute amount. The expression “increasing according to absolute amount ” in this context means that the signal in question increases at least in sections in the direction of a time axis T, i.e. that the voltage signal S10 comprises first signal sections SA1 with a signal flank S11 with positive gradient. The expression “decreasing according to absolute amount ” means in this context that the signal in question decreases at least in sections in the direction of a time axis T, i.e. that the voltage signal S10 comprises second signal sections SA2 with a signal flank S12 with a negative gradient. The first signal sections SA1 and the second signal sections SA2 may generally be signal sections which are continuous in the course of time, that is to say uninterrupted in time, or signal sections that are discontinuous in time, that is to say interrupted in the course of time.
The first signal sections SA1 do not necessarily consist of increasing signal flanks S11, i.e. they do not have to be formed exclusively from a signal flank S11 that increases according to absolute amount. The first signal sections SA1 may also comprise subsections without a gradient or subsections with a negative gradient. Likewise, the second signal sections SA2 may not necessarily consist of decreasing signal flanks S12, i.e. the same do not have to be formed exclusively from a decreasing signal flank S12 according to absolute amount. The second signal sections SA2 may also have subsections without a gradient or subsections with a negative gradient.
The first signal sections SA1 of an embodiment of the first voltage signal S1 according to the invention may, however, in particular be defined in such a way that they are formed of or exclusively consist of increasing signal flanks S11 according to the definition according to the invention. Alternatively or additionally, the second signal sections SA2 of an embodiment of the first voltage signal S1 according to the invention can be defined in such a way that they are formed of or exclusively consist of decreasing signal flanks S12 according to the definition according to the invention.
An intermediate section S13 defined according to the invention forms a local maximum and differs both from the signal flank S11, which is increasing according to absolute amount, and the signal flank S12, which is decreasing according to absolute amount, in that the signal shape of the intermediate section S13 according to the invention differs over time both from the signal shape of the signal flank S11 which is increasing according to absolute amount and from the signal shape of the signal flank S12 which is decreasing according to absolute amount.
In addition, the signal intermediate section S13 can be defined in that the same comprises a time-dependent gradient which comprises a value of a maximum of 10 degrees. Additionally or independently of this, it can be defined that the signal flank S11, which increases according to absolute amount, lies, in the course of time, immediately before the signal intermediate section S13, has a value of more than 10 degrees and preferably a value of more than 20 degrees. It can also be defined additionally or independently of this that the absolute value of the decreasing signal flank S12, which is immediately after the signal intermediate section S13, comprises a value of more than 10 degrees and preferably a value of more than 20 degrees. In the case of these variants, it can be defined in particular that the temporal length of the signal flank S11 which increases according to absolute amount is larger than the temporal length of the signal intermediate section S13. In these variants, it can also be defined in particular that the temporal length of the signal flank S12 which is decreasing according to absolute amount is larger than the length of the signal intermediate section S13.
An embodiment of the first voltage signal S10, which is used in the method according to the invention, comprises a plurality of signal flanks S11 which are increasing according to absolute amount, each of which is immediately followed in time by an intermediate section S13, wherein this intermediate section S13 is followed directly in time by a signal flank S12 that decreases according to absolute amount. An example of this embodiment is shown in
An embodiment of the first voltage signal S10 used in the method according to the invention may be formed of a temporal sequence of signal section groups G1 each consisting of an increasing signal flank S11, of a temporally directly following intermediate section S13 and a temporally directly following decreasing signal flank S12, wherein each signal section group G1 may in particular have a sawtooth shape or a trapezoidal shape or essentially one of these shapes, this means that each of the signal flank S11, the intermediate section S13 and the signal flank S12 are formed straight-line.
In the embodiments of the method according to the invention, the second voltage signal S20 comprises at least one relatively high-frequency signal section S21. In this case, the second voltage signal S20 may comprise have at least one connection signal section S22, which connects respective two relatively high-frequency signal sections S21. as shown in
An example of an embodiment of the method in which a control of an actor 1, which comprises three control sections A1, A2, A3, with a first voltage signal S10 with trapezoidal shape and the second voltage signal S20 is shown in
In the embodiment of
In the case of the first voltage signal S10 shown in
Furthermore, the amount of the gradient of the decreasing signal flank S12 is set in such a way that, due to the comparatively higher speed of the change of the state of the shape of the actor 1 which is caused by the same, no static friction between the friction element F and the friction surface 90a occurs, but sliding friction results. In the time section of the decreasing signal flank S12, the inertia of the element 90 to be driven relative to the friction force which occurs between the contact surface FK of the friction element F, which is in contact with the friction surface 90a of the element 90 to be driven, and the friction surface 90a is so large that with the comparatively rapid change of the state of the shape of the actor 1 and the position of the contact surface FK of the friction element F a relative movement and thus a slide friction between the contact surface and the FK friction surface 90a of the element 90 to be driven results. In this period of time, the element 90 to be driven is not advanced, but a return movement of the contact surface FK of the friction element F relative to the friction surface 90a of the element 90 to be driven occurs. After the temporal end of the signal flank S12 is reached, an increasing signal flank S11 of a further signal section group G1 can in turn be adjoined in order to achieve a further advance of the element 90 to be driven.
In general, in the case of a voltage signal S10 to achieve a first drive direction, a signal section group G1 is realized in such a way
(a) that the first signal section SA1 comprises at least one section which comprises a gradient with which a movement speed of the friction element F results with which a static friction state between the friction element F, which is disposed on the actuation surface 1a, and the friction surface 90a of the element 90 to be driven, on which the friction element F rests, occurs,
(b) that the second signal section SA2 comprises a gradient according to absolute amount at every position, with which a movement speed of the friction element F results, at which a slide friction state between the friction element F, which is disposed on the actuation surface 1a, and the friction surface 90a of the element 90 to be driven, on which the friction element F rests, occurs.
The friction element F assumes a neutral state with regard to its shape or its orientation or both aspects in case the actor 1 is in a neutral state. Both in the first signal section SA1 and in the second signal section SA2 the friction element F in its orientation or in its state of shape is in a state of motion contrary to the neutral state. In the embodiments of the method according to the invention, the intermediate section S13, which is located between the first signal section SA1 and the second signal section SA2, is a signal section in which no change in the state of the shape of the actor 1 occurs or in which a change in the state of the shape of the actor 1 occurs which is significantly smaller in comparison with the first and second signal sections SA1, SA2. While a signal strength of an intermediate section S13 is applied, a restitution of the friction element F and optionally of the friction element F together with a holding device, in which the actor 1 is received, from a respective momentary state of motion into the neutral state may take place, before the friction element F is again brought into a state of motion as soon as the actor 1 is controlled with the first signal section SA1 or the second signal section SA2.
A special embodiment of the first voltage signal S10 used in the method according to the invention for generating the first drive direction of the element 90 to be driven comprises, due to a corresponding starting point for the first voltage signal S10, a plurality of signal section groups G2 each consisting of the sequence of a signal flank S12 which decreases according to absolute amount, of a temporally directly subsequent intermediate section S13 and a temporally directly adjoining signal flank S11 which increases according to absolute amount, wherein the increasing signal flank S11 comprises a gradient which is smaller according to absolute amount than the decreasing signal flank S12. In this embodiment of the first voltage signal S10, when such a signal section group G2 and a decreasing signal flank, which is next in time after this signal section group, occurs, the occurrence of such a group does not necessarily follow. Accordingly, in the case of the first voltage signal S10, after a decreasing signal flank S12, other signal sections may also follow temporally which do not have an intermediate section S13 defined according to the invention. Further, in the case of a first voltage signal S1, a decreasing signal flank S12 according to absolute amount can also be temporally directly followed by an increasing signal flank S11. According to an embodiment of the method according to the invention, however, the first voltage signal S10 can also have a plurality of such groups which temporally follow one another. The signal section group G2 can in particular have a sawtooth shape or a trapezoid shape.
In general, for achieving the second drive direction a signal section group G1 of a voltage signal S10 is realized in such a way
(a) that the first signal section SA1 has, at least in sections and in particular at each position, a gradient with which a speed of motion of the friction element F results, in which a slide friction state between the friction element F, which is disposed on the actuating surface 1a, and the friction surface 90a of the element 90 to be driven, on which the friction element F rests, occurs,
(b) that the second signal section SA2 comprises at least one section which comprises a gradient with which a motion speed of the friction element F results with which a static friction state between the friction element F, which is disposed on the actuation surface 1a and the friction surface 90a of the element to be driven 90, on which the friction element F rests, occurs.
A special variant of the first voltage signal S10 which is used in this regard for generating the second drive direction of the element 90 to be driven comprises, with a corresponding starting point of the first voltage signal S10, a plurality of signal section groups G2 each consisting of the sequence of a decreasing signal flank S12 according to absolute amount, a temporally directly following intermediate section S13 and an increasing signal flank S11 according to absolute amount which temporally directly follows, wherein the increasing signal flank S11 according to absolute amount comprises a larger gradient than the decreasing signal flank S12.
Furthermore, the amount of the gradient of the decreasing signal flank S12 is set such that, due to the slower speed of the change in the shape state of the actor 1 caused by this, static friction between the friction element F and the friction surface 90a predominates. In this time section, with the change of the shape state of the actor 1, the position of the contact surface FK (
After reaching the temporal end of the signal flank S12, an increasing signal flank S11 of a further signal section group G1 may in turn be adjoined in order to achieve a further advance of the element 90 to be driven. In the embodiment of
The high-frequency signal section S21 of the second voltage signal S20 begins in the embodiments of the method according to the invention within the time interval tz in the intermediate sections S13 and extends along the subsequent increasing signal flank S11 and also along a part of the respective subsequent intermediate section S13. The changes in position U of a reference point on the first end face 11 or of the actuation surface 1a, in particular on which the friction element F is arranged, which results from this control, is shown over time in
In all embodiments of the method according to the invention, it can be provided that the signal flanks S11 of the first voltage signal S10, which increase according to absolute amount, run linearly and thus have a positive and temporally constant gradient. In this case, several groups G1 and G2 and in particular a direct succession of groups G1, of groups G2 or alternately of groups G1 and G2 may have increasing signal flanks S11 that run linearly and thus have a positive and temporally constant gradient. The increasing signal flanks S11 may each have the same gradient.
As an alternative or in addition to this, the embodiments of the first voltage signal S10 which is used in the method according to the invention may comprise signal flanks S12 which decrease according to absolute amount and run linearly and thus have a gradient which is negative and is constant over time. Several groups G1 and G2 and in particular a direct succession of groups G1, of groups G2 or alternately of groups G1 and G2 may comprise decreasing signal flanks S12, which run linearly and thus have a negative and temporally constant gradient. In this case, the decreasing signal flanks S12 can each have the same gradient.
An embodiment of the first voltage signal S10 which is used in the method according to the invention may comprise intermediate sections S13 which run linearly. In this case, a plurality of groups G1 and G2 and in particular a direct succession of groups G1, of groups G2 or of alternately groups G1 and G2 may comprise intermediate sections S13 which run linearly. In each case It can be provided that the intermediate section S13 is a section with a gradient has the value zero in sections or, as shown in the examples in
The control of the second control section A2 with the second voltage signal S20 temporally begins according to the invention within the time interval tz of the signal intermediate section S13 of the first voltage signal S10, which is located in particular by a time section TZ before a signal flank which causes a relative movement between the friction element F which is arranged on the actuation surface 1a and the friction surface 90a of the element 90 to be driven.
In particular, if a frequency of the first voltage signal S10 is defined from the temporal sequence of two signal intermediate sections S13, in each case after an increasing signal flank S11 or in each case after a decreasing signal flank S12, the frequency of the second voltage signal S20 may be, at least in these signal intermediate sections S13, a factor of at least 10 times higher compared to the frequency of the first voltage signal S10 defined in this way.
In general, the high-frequency signal section S21 of the second voltage signal S20 may be sinusoidal.
According to an embodiment of the method according to the invention, in particular in combination with one of the features of the same described above, the second voltage signal S20 begins at a point in time which occurs after at least 10% and at most 90% of the time interval tz of the signal intermediate section S13 has passed. Alternatively or additionally, the begin of the second voltage signal S20 occurs at a point in time which lies 50% of the time interval of the signal intermediate section S13 before the end of the same.
According to an embodiment of the method according to the invention, in particular in combination with one of the previously described features of the same, the second voltage signal S20 extends over a temporally directly following or temporally adjacent signal section SA1 with a increasing signal flank S11 uninterruptedly up to a temporally following signal intermediate section 13 and ends in particular with the expiration of a time section TN within the time interval tz this signal intermediate section 13 or with its end. Further, according to one embodiment of the method according to the invention, in particular in connection with one of the previously described features of the same, the second voltage signal S20 may continue uninterruptedly over a temporally directly following or temporally adjacent signal section SA2 with a decreasing signal flank S12 up to a temporally following intermediate signal section 13 and may end within the time interval tz of this signal intermediate section 13 or with its end.
According to an embodiment of the method according to the invention, in particular in combination with one of the features of the same described above, the maximum amplitude of the second voltage signal S20 amounts at most to 50% of the maximum amplitude of the first voltage signal S10.
According to a further embodiment of the method according to the invention, in particular in combination with one of the previously described features thereof, the following takes place:
(a) during the activation of the first control section A1, simultaneous activation of a plurality of first control subsections, which form the first control section A1 and which are located one behind the other in the longitudinal direction L, with the first voltage signal S10,
(b) during the activation of the second control section A2, simultaneous driving of a plurality of second control sub-sections, which form the second control section A2 and are located one behind the other in the longitudinal direction L, with the second voltage signal S20.
According to a further embodiment of the method according to the invention, in particular in combination with one of the above-described features of the same, a control of a third control section A3, which is deformable by an electrical voltage, with the first voltage signal S10 takes place simultaneously with the control of the first control section A1 with the first voltage signal, wherein the third control section is arranged in such a way that the second control section A2 is located between the first and the third control section A3.
In
As seen from the drive device K1, the holding part 44 presses on the friction element F from the outside in a direction which runs along the longitudinal direction L to the actuation surface 1a. Due to the movements of the actuation surface 1a, which are caused by the deformation states of the actor 1 by corresponding application of voltage as shown in
The actor 1 according to the invention with the holding device 40 may be built in or integrated into a support device 50 of a motor M, wherein the support device is disposed spatially fixed, i.e. arranged stationary in a spatial reference system. In case of a dynamic deformation of the actor 1 and the resulting movement of the actuation surface 1a, the friction element F moves relative to the support device 50 or the spatial reference system and causes a movement of the element 90 to be driven, which is in frictional contact with the friction element F and is guided by a guide device 95 in a guide path predetermined by the latter. The guide device 95 is in particular arranged in a stationary manner relative to the support device 50 as a reference system.
In the embodiment according to
The support device 50 may comprise a pretensioning device 60 which exerts a force on the drive device K or on the friction element F, which is directed from the base plate 51 to the friction element F and presses the same against the element 90 to be driven. In the embodiment of the drive device K of
A motor M with a drive device K and the support device 50 is shown schematically in
In a further embodiment, the friction element F can be located on an outer surface 44a of the holding part 44 of the holding device 40 as actuation surface 1a, which is oriented opposite to an inner surface 44b of the holding part 44 on which the actor 1 rests. In this regard, it can be provided in particular that the friction element F is fastened to the holding part 44. It can be provided that the friction element F extends with its longitudinal direction LF transversely to the longitudinal direction L or along the longitudinal direction L of the actor 1 to a friction surface 90a of the element 90 to be driven.
An embodiment of the drive device K with these features is shown in
The embodiment of the drive device K2 shown in
It is also conceivable that the longitudinal direction LF of the friction element F extends transversely to the longitudinal direction L of the actor 1 towards a friction surface 90a of the element 90 to be driven. The friction element F may also be arranged between the holding part 244 and in particular the inner surface 244b of the holding part 244 and the actor 1.
Due to the position of the actor 1, a central axis Z of the drive device K2 can be defined, which can run along or in particular in the direction of the longitudinal direction L of the actor 1. The central axis Z can be an axis of symmetry of the mounting device 240 or a central axis of the same. The connecting parts 245, 246 extend along the central axis Z. The connecting parts 245, 246 each have an outer surface 245c and 246c, which run along the longitudinal direction L of the actor 1 or the central axis Z and are oriented opposite to one another. The receiving part 243, the holding part 244 and the connecting parts 245, 246 can be manufactured as one piece. Alternatively, as shown in
The mounting device 240 can be realized as a tensioning frame 241 into which the control sections of the respective actor 1 are clamped between the receiving part 243 and the holding part 244 and thereby exert a clamping force in the form of a compression force on the actor 1, which acts in the longitudinal direction L of the actor 1. In this embodiment of the mounting device 240, by the clamping force the actor 1 is resiliently biased in a predetermined contracted state with regard to the longitudinal direction L, for example in a reference state or a neutral state. An elastic pretension of the actor 1 is given in particular by the fact that the holding part 244 is plate-shaped or web-shaped. In particular, the holding part 244 can be formed at least in sections from an elastic material. Due to this pretension, the actor 1 is returned more quickly from an expanded state to a contracted state. The holding device 240 is realized in such a way that the same extends at least on one side of the actor 1 over a distance which runs from the actuating surface 1a to the support surface 1 b and thus surrounds or clasps the actor 1 in the longitudinal direction L.
The first end section 245a of a first connecting part 245 and the second end portion 246a of a second connecting part 246 is located on the holding part 244 or the actuation surface 1a of the actor 1. In the embodiments of holding device 240 it may be provided that each of two opposite end sections 247 or 248 of the holding part 244 is attached to the respective end section or end section 245a, 245b of the at least one connecting part 245 or 246, in each case for example by means of a connecting element 245d or 246d. It can be provided that the position of the holding part 244 relative to the receiving part 243 or to the connecting parts 245 or 246 and in particular to the end sections 245a or 245b can be adjusted by means of an adjusting device. The adjustment device may be realized by the connecting elements 245d or 246d can be implemented, with which the distance between a respective outer end section 245d or 246d can be adjusted. By adjusting the position of the holding part 244 relative to the at least one connecting part 245 or 246, the clamping force acting on the actor 1 may be adjusted.
The friction element F can be located centrally on the central axis Z. Alternatively or additionally, the actor 1 can also be located centrally on the central axis Z, wherein the longitudinal direction L can coincide with the central axis Z. In general, the longitudinal direction L may be located in at a distance from the central axis Z, which is different from the value zero. In the embodiment of the drive device K2 shown in
In the embodiment of the drive device K2, the actor 1 can be realized according to one of the embodiments of the same described herein. In
In the drive device K3, a first end section 347 of the holding part 344 is located above the first end section 345b of the first connecting part 345 and the holding part 344 extends transversely to the longitudinal direction L from the first end section 345b of the first connecting part 345 to the second end portion 346b of the second connecting part 346. Here, the first end section 347 of the holding part 344 is located, when viewed in the longitudinal direction L, over the first end portion 345b of the first connecting part 345 and the second end portion 348 of the holding part 344 is formed with the second end portion 346b of the second connecting part 346 as one piece. The first end section 347 of the holding part 344 may be formed as one piece with the first end section 345b of the first connecting part 345 or, as shown in
The friction element F is disposed on an elevation 344e of the outside 344a of the holding part 344. In the embodiment of the drive device K3, which is shown in
The drive device K3 may comprise features of the drive device K2 and vice versa.
In case that the actor 1 is electrically controlled with corresponding voltage signals from a signal generating device V, the drive devices K2 and K3 according to
In the following essentially features are described in which the drive device K4 differs from the drive device K2. On the holding part 444 or the actuation surface 1a of the actor 1a first end section 445a of a first connection part 445 and a second end portion 446a of a second connection part 446 is located. The receiving part 443, the holding part 444 and the connecting parts 445, 446 form a receiving space 449 in which the actors 401, 402 are located. The longitudinal directions L401, L402 of the actors 401, 402 run parallel to one another. In general, the longitudinal direction L401 runs along the longitudinal direction L402. The outer surfaces 445c, 446c of the connecting parts 445, 446, which are oriented opposite to one another, run along the longitudinal directions L401, L402 of the actors 401, 402 or the central axis Z.
The holding part 444 of the drive device K4 may have any shape and, in the embodiment shown, has the shape of a plate or of a web. A first end portion 447 of the holding part 444 is located above the first end portion 445b and a second end portion 448 of the retaining member 444 is located above the second end portion 446b. Here is the first end portion 447 of the holding part 444, when viewed in the longitudinal direction L401, is located above the first end portion 445b of the first connecting part 445 and the second end portion 448 of the holding part 444, when viewed in the longitudinal direction L402, is located above the second end portion 446b of the second connecting part 446. One or both of the end sections 447, 448 of the holding part 444 can be formed as one piece with the respective end section 445b, 446b or, as shown in
In general, the longitudinal directions L401, L402 can be located at a distance from the central axis Z which differs from the value zero. The actors 401, 402 can be located as a whole laterally and on opposite sides of the central axis Z. In the embodiment of the drive device K4 shown in
The drive device K4 may comprise features of the drive device K2 or the drive device K3 and vice versa. Also, the definitions made in relation to the rive device K2 and K3 may be applied to another drive device described herein and in particular to the drive device K4.
In
The support device 450 is realized as a base plate 451 which in particular can have the function of a storage plate or connecting plate. The drive device K4 may be disposed or supported on a section of the support device 450 or of the base plate 451, wherein the section is located at a distance from the friction element F. In this case, the friction element F extends with its longitudinal direction LF in the longitudinal direction L or along the longitudinal direction L of the actor 1 towards the friction surface 90a of the element 90 to be driven. As an alternative thereto, it can be provided that the friction element F extends with its longitudinal direction LF transversely to the longitudinal direction L of the actor 1 towards a friction surface 90a of the element 90 to be driven. The friction element F can also be disposed between the holding part 444 and in particular between the inner surface 444b of the holding part 444 and the actor 1.
The support device 450 shown in
The pretensioning device 460 is arranged between the base plate 451 and the drive device K4 and is shaped in such a way that the same presses the friction element F of the drive device K4 against the element 490 to be driven. The pretensioning device 460 of
Furthermore, the pretensioning device 460 of
The pretensioning device 460 can also be embodied in other ways. For example, the drive device K4 can be positively locked and supported in a recess in the base plate 461. In this regard, it can be provided that the shape of the recess allows the drive device K4 to move relative to the base plate 461, wherein a spring is additionally acting between the recess and the drive device K4, which presses the drive device K4 against the element 90 to be driven.
The support device 450 can also be realized in a different manner and for example realized as a mounting device so that the motor comprises no pretensioning device. In the motor M with an embodiment of the support device 450 according to the invention, an embodiment of the actor 1 described herein can be built into or integrated.
The guide device is formed on the base plate 451 and, in particular, provides a guide track which extends transversely to the central axis Z or at least to one of the longitudinal directions L401, L402 run, so that the element 90 to be driven is moveable due to the deformations of the actor 1 and the movement of the friction element F relative to the base plate 51 transversely to the central axis Z or transversely to at least one of the longitudinal directions L401, L402.
The guide device is in particular arranged stationary relative to the support device 450 as a reference system.
It can be seen that the drive device K4 or its friction element F can move an element to be driven (not shown in these figures) in two mutually opposite directions, in particular in that only one of the two actors 401 or 402 is alternately contracted and expanded. In
Number | Date | Country | Kind |
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10 2019 001 579.7 | Mar 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/055668 | 3/4/2020 | WO |