Patent Publication Number: US-2023159100-A1

Title: Control Element And Vehicle With Content Element

Description:
FIELD OF THE INVENTION 
     A control element and a vehicle with a control element are specified. 
     BACKGROUND OF THE INVENTION 
     In order to provide feedback to a vehicle driver in certain driving situations, there are vehicles, such as motor vehicles, whose steering wheel is equipped with a vibration device for generating haptic feedback. The vibration device can, for example, be coupled to a lane assist and embodied in such a way that the steering wheel can provide feedback to the vehicle driver, for example by means of a click or a vibration, when the vehicle leaves its lane, so that the driver can respond accordingly. 
     So far, so-called linear resonator or unbalanced motor solutions, also known as “linear resonant actuator” (LRA) or “eccentric rotating mass” (ERM), have been used to generate such haptic feedback, which can only generate a predefined vibration. 
     At least one object of particular embodiments is to provide a control element. At least one further object of particular embodiments is to provide a vehicle with a control element. 
     These objects are achieved by subject-matters according to the independent patent claims. Advantageous embodiments and developments of the method and the subject-matter are characterized in the dependent claims, and are also disclosed by the following description and the drawings. 
     SUMMARY OF THE INVENTION 
     According to at least one embodiment, a control element comprises at least one piezoelectric component. The control element can in particular be an element operated by a user, by means of which haptic feedback and/or input functionality can be enabled. The control element can also be referred to as a so-called human-machine interface (HMI). 
     According to at least one further embodiment, a vehicle comprises a control element with a piezoelectric component. 
     The features and embodiments described above and below apply equally to the control element and the vehicle. 
     According to a further embodiment, the control element has at least one tubular section with a cavity at least partially surrounded by a wall. The piezoelectric component is arranged in the cavity. The piezoelectric component may in particular be provided and embodied to generate a haptic signal at at least a partial region of the control element. In particular, this can mean that a haptic signal can be generated, by means of a suitable electrical activation of the piezoelectric component, for a user of the control element who, for example, touches it with a hand or at least partially encloses it. Alternatively or additionally, the piezoelectric component may be provided and arranged to detect an action of pressure on at least a part of the piezoelectric component. In particular, this may mean that an action of pressure on the piezoelectric component, which is exerted for example by the user of the control element, can be converted into an electrical signal. 
     The control element can, for example, be a control element for a vehicle. Particularly preferably, the control element may be a steering element for a vehicle, in particular a steering element of a vehicle. Alternatively or additionally, the control element may be a brake element, for example a brake lever, and/or a gear selection element, for example a gearshift or a gear shift lever. Furthermore, the control element may be an input component, for example a pen-type input component, which may further be used, for example, in connection with a display component, for example in a vehicle. 
     The piezoelectric component may be connected to a drive component for generating an electrical drive signal for operating the piezoelectric component and/or for detecting an electrical signal generated by the piezoelectric component. The drive component, for example in the form of a control unit of the vehicle or at least a part thereof in the case of a control element for a vehicle, may be completely or partially integrated in the control element. Furthermore, the drive component can also be arranged completely or partially outside the control element and connected to the piezoelectric component, for example, via electrical lines that extend into the control element and run within it. 
     According to a further embodiment, the control element is embodied as a steering element for a vehicle and comprises a steering rod or is a steering rod that has the tubular section. In this case, the vehicle can preferably be a conventionally or electrically operated motorcycle, such as a motorcycle, a so-called trike or a so-called quad. Furthermore, the vehicle may be a bicycle, for example a so-called e-bike or also a conventional bicycle. The steering rod, which may also be referred to as a steering handlebar, may preferably be formed at least in the region of the tubular section as a tube and, particularly preferably, substantially completely as a tube. In this context, the steering rod may be straight, slightly bent or formed with bent or kinked sections. 
     Particularly preferably, the tubular section can be a handle region of the control element, i.e. the region that is enclosed or at least touched by a hand of the user during normal use. In the case of a control element embodied as a steering rod, the handle region can thus be the region that is enclosed or at least touched by a hand of the user, i.e. in particular of the vehicle driver, during normal use. In the case of a motorcycle steering rod, the handle region may also be rotatable. In particular, the steering rod may have two handle regions. Accordingly, the steering rod may also have at least two tubular sections, each having a cavity at least partially surrounded by a wall. In at least one or both of the cavities, a respective piezoelectric component is preferably arranged. Alternatively or additionally, at least one tubular section with at least one piezoelectric component can also be present outside the handle regions. 
     Alternatively, the control element may be embodied as a steering element for a vehicle and may comprise or be a steering wheel comprising the tubular section. In this case, the vehicle may preferably be a conventionally powered and/or electrically powered motor vehicle such as a passenger car or a truck or other vehicle with a steering wheel. The steering wheel may preferably be formed as a curved tube at least in the region of the tubular section, and particularly preferably substantially completely as a curved tube. In particular, the steering wheel may be substantially circular or at least approximate a circular shape. As already described for the control element in general and for the steering rod, the steering wheel can have one and preferably at least two handle regions which are each enclosed or at least touched by a hand of the user, i.e. in particular of the vehicle driver, during normal use. Accordingly, the steering wheel may also have at least two tubular sections each having a cavity at least partially surrounded by a wall. In at least one or both of the cavities, a respective piezoelectric component is preferably arranged. Alternatively or additionally, at least one tubular section with at least one piezoelectric component may also be present outside the handle regions. 
     In the following, reference is made to a tubular section of the control element having a cavity with at least one piezoelectric component. The control element can also have more than one tubular section with a cavity with at least one piezoelectric component, as described above by way of example for a control element embodied as a steering element, wherein each of the tubular sections with the respective at least one piezoelectric component can have one or more of the features described below. The tubular sections with the respective at least one piezoelectric component can be of the same or different design and thus have the same or also different functionalities. 
     The piezoelectric component particularly preferably has a piezoelectric actuator based on a piezoelectric material, in particular a piezoelectric ceramic material or a piezoelectric polymer material. For example, the piezoelectric actuator may be of multilayer construction with a plurality of piezoelectric layers and internal electrodes arranged one on top of another along a stacking direction. Furthermore, the piezoelectric actuator may have a longitudinal direction, which may correspond to the direction with the largest extension. In particular, the longitudinal direction may be perpendicular to the stacking direction. 
     By applying a suitable electrical signal, the piezoelectric actuator can perform a change of an extension in at least one direction, wherein this change can be part of the haptic signal, which can be passed on to a user directly or indirectly via further components of the piezoelectric component and/or the control element. When an AC voltage is applied, a periodic change and thus a vibration can be generated. In particular, the change in the extension of the piezoelectric actuator may be caused by at least the d31 effect and may correspond at least to a change in the length of the piezoelectric actuator along the longitudinal direction. 
     Using a piezoelectric actuator to generate a haptic signal offers significant advantages. A piezoelectric actuator has a short response and decay time. Accordingly, the time and period during which the haptic signal is generated can be very precisely defined and adjusted. Furthermore, by varying the drive signal applied to the piezoelectric actuator, for example in terms of frequency, electrical voltage, pulse sequence and signal type, it is possible to determine the amplitude, frequency and time duration with which the piezoelectric component is driven. Different drive signals can make it possible to generate different haptic signals. 
     Piezoelectric actuators have a small volume compared to other components for generating a vibration, for example unbalance motors or linear resonators. By using a piezoelectric actuator in the piezoelectric component, it is thus possible to design a component that has a comparatively small space requirement. 
     The piezoelectric component may further comprise at least one mechanical amplification element attached to the piezoelectric actuator such that the change in length of the piezoelectric actuator along its longitudinal direction moves a portion of the mechanical amplification element in a direction perpendicular to the longitudinal direction. 
     The amplification element may comprise metal or be made of metal and, particularly preferably, may be a metal bracket, for example with two end regions attached to end regions along the longitudinal direction of the piezoelectric actuator and with a middle region between the end regions spaced from the piezoelectric actuator The mechanical amplification element may be attached to the piezoelectric actuator by, for example, an adhesive bond. The metal of the amplification element may be titanium, for example. Titanium may have the advantage that its coefficient of thermal expansion is very similar to the coefficient of thermal expansion of the piezoelectric actuator, so that there is little or no mechanical stress when the temperature changes. 
     The mechanical amplification element can convert the length change of the piezoelectric actuator caused by the d31 effect into a stroke movement perpendicular to the length change, wherein the direction of the stroke movement can correspond to the stacking direction. The stroke movement may have a much larger amplitude than the length change. For example, the amplitude of the stroke movement may be 5 to 40 times the amplitude of the length change. Thus, by combining the piezoelectric actuator with the amplification element, for example, significantly stronger movements can be produced. 
     The mechanical amplification element may be free of indentations and have a constant wall thickness. The absence of indentations in the amplification element may allow for ease of fabrication of the amplification element. In alternative embodiments, the amplification element may include at least one indentation that reduces a mechanical resistance to deformation of the mechanical amplification element. In particular, for amplification elements having a thickness where deformations of the amplification element require a lot of force, the use of indentations in the amplification element may be useful as the indentations may facilitate deformation of the amplification element. 
     In particular, the piezoelectric component may be arranged in the tubular section such that it has a force effect in a radial direction with respect to the tubular section, i.e., perpendicular to a tube axis of the tubular section. In other words, the piezoelectric component may, for example in the case of an embodiment with at least one amplification element described above, be arranged such that the stroke direction runs along a radial direction of the tubular section. 
     According to a further embodiment, the piezoelectric component is arranged in the tubular section such that the longitudinal direction of the piezoelectric actuator runs along a tube axis of the tubular section. If the tubular section has a curved course, “running along the tube axis” may mean, for example, a tangential approach to the tube axis or to a longitudinal direction of the tubular section. In such an arrangement, which may also be referred to as a longitudinal arrangement, a piezoelectric component may be used that has a linear extent that may be far greater than a diameter of the tubular section. 
     According to a further embodiment, the piezoelectric component is arranged in the tubular section in such a way that the longitudinal direction of the piezoelectric actuator is transverse to the tube axis of the tubular section. In such an arrangement, also referred to as a transverse arrangement, the longitudinal extent of the piezoelectric component is limited by the diameter of the tubular section. However, this allows several piezoelectric components to be placed close together along the tube axis. 
     According to another embodiment, a plurality of piezoelectric components is arranged in the tubular section, wherein the piezoelectric components may be the same or different. For example, the plurality of piezoelectric components may be arranged side by side to form an array. For example, each of the piezoelectric components can be read and/or driven separately from the other piezoelectric components. This allows different piezoelectric components to perform different functions. Alternatively, several piezoelectric components can be read out or driven together, so that the functionality can be multiplied compared to a single piezoelectric component. 
     According to a further embodiment, the control element has at least one interaction element through which a user can cause an action of pressure on the piezoelectric component and/or to which the piezoelectric component can transmit the haptic signal for forwarding to the user. In particular, the piezoelectric component can act on the interaction element by the lifting movement described above. Furthermore, the interaction element can transmit a pressure caused by a user on the interaction element to the piezoelectric component so that the action of pressure can be detected by the piezoelectric component by generating an electrical signal in the piezoelectric component. In this case, the interaction element can form a button that can be actuated by the user, by means of which a specific function can be triggered. 
     The interaction element may, for example, be in the form of a button or a plunger. In the case of a piezoelectric component having an amplification element as described above, the interaction element may be arranged or attached to the amplification element. The interaction element may be arranged at least partially in an opening in the wall of the tubular section and extend into the cavity. Due to the stroke movement of the piezoelectric component, the interaction element, which in the rest position prior to the stroke movement may be recessed in the opening or may also be arranged protruding from the opening, may be pressed (further) out of the opening and thus cause a perceptible haptic signal for a user. Conversely, the interaction element can protrude from the opening in a rest position and can be pressed by a user in the direction of the piezoelectric component. 
     Furthermore, the wall can have an interaction region which forms the interaction element or at which a previously described interaction element is arranged within the cavity of the tubular section. In this case, the wall does not have an opening and the transmission of the haptic signal or the action of pressure takes place at least partially via the interaction region of the wall. Thus, the piezoelectric component can exert a force on the interaction region of the wall in the tubular section when generating the haptic signal, either directly or via an interaction element. In this regard, it may be advantageous if the wall in the interaction region has a greater mechanical deformability than in other regions, so that the interaction region may have sufficient flexibility, for example, to transmit a haptic signal to a user. For example, the wall in the interaction region may be thinner than in other regions and/or surrounded by an indentation around the interaction region. 
     According to a further embodiment, the piezoelectric component is arranged between the interaction element and a back side region of the wall opposite the interaction element as viewed from the piezoelectric component. A support element may be arranged between the piezoelectric component and the back side region of the wall in the cavity of the tubular section. The support element may, for example, have a bearing surface for the piezoelectric component and, on a surface opposite the bearing surface, a support surface which nestles against the back side region. The support element allows the stroke movement of the piezoelectric component to be directed completely in the direction of the interaction element. 
     Alternatively, it is also possible for the piezoelectric component to be arranged between two interaction elements. The interaction elements can be arranged, in particular in relation to the tube cross section, radially opposite one another. 
     According to a further embodiment, the control element has a handle element that surrounds the tubular section with the piezoelectric component and that has a plastic that is softer than the wall of the tubular section. For example, at least the tubular section of the control element may comprise a metal. The handle element may comprise or be made of a plastic, for example a rubber, and/or also a metal. 
     The described invention enables the integration of haptic feedback and/or the integration of functional buttons in a control element. For example, in the case of a control element embodied as a steering element, the integration can take place in the handle region of a steering rod or a steering wheel and serve to enable the driver to be specifically notified or alerted via a tactile or palpable signal, for example in a dangerous situation, when parameters are exceeded or in the case of other messages. Furthermore, the dual functionality of the piezoelectric component can also be used to actively trigger control commands by applying targeted pressure in the handle region. 
     For the realization of a haptic feedback, in particular in the handle region, the movement of the piezoelectric actuator in the longitudinal or transverse direction relative to the tube axis of the tubular section is preferably used as described above. The amplification element of the piezoelectric component can convert this into an amplified movement in a radial direction, i.e. perpendicular to the longitudinal and transverse directions. This mechanical translation pushes or spreads the tubular section or at least the interaction element apart and is responsible for noticeable haptic feedback. Preferably, the movement can act on an interaction element, for example a plunger, wherein the movement can be transferred to the user. In this way, it can be achieved that the haptic feedback can act substantially locally or preferably only locally in a very defined region of a contact surface to the user. 
     In contrast to ERM and LRA solutions, the use of the piezoelectric component can enable the use of different drive signals in the form of one or more of the following variable parameters electrical voltage, frequency, signal type, pulse sequence. The variation of the drive signal results in a changed perception by the user, which enables the use of different signals for different functions. The haptic feedback can also only occur locally in a defined region at the contact surface to the user, while conventional solutions can only generate global feedback. 
     As described above, the use of the piezoelectric component also offers the advantage that the piezoelectric component can also be used as a pushbutton in a dual function. By applying pressure to the piezoelectric component, the user can generate an electrical signal that can be used to trigger a defined function, such as switching displays and/or accepting or rejecting calls, as well as other functions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, advantageous embodiments and further developments are revealed by the embodiments described below in connection with the figures, in which. 
         FIG.  1 A  shows a schematic illustration of an embodiments of a control element. 
         FIG.  1 B  shows a schematic illustration of an embodiment of a vehicle with a control element. 
         FIG.  2    shows a schematic illustration of another vehicle with a control element according to a further embodiment. 
         FIG.  3 A  shows a schematic illustration of a piezoelectric component according to a further embodiment, 
         FIG.  3 B  shows a schematic illustration of the piezoelectric component of  FIG.  3 A  in a sectional view. 
         FIG.  4 A  shows a schematic illustration of a control element in a perspective view according to a further embodiment. 
         FIG.  413    shows a schematic illustration of the control element of  FIG.  4 A  in a sectional view. 
         FIG.  4 C  shows a schematic illustration of the control element of  FIG.  4 A  in another sectional view. 
         FIG.  5    shows a schematic illustration of a control element according to a further embodiment. 
         FIG.  6    shows a schematic illustration of a control element according to yet a further embodiment. 
         FIG.  7    shows a schematic illustration of a control element according to another embodiment. 
         FIG.  8 A  shows a schematic illustration of a control element in a perspective view according to another embodiment. 
         FIG.  8 B  shows a schematic illustration of the control element of  FIG.  8 A  in a sectional view. 
         FIG.  8 C  shows a schematic illustration of the control element of  FIG.  8 A  in another sectional view. 
     
    
    
     In the embodiments and figures, identical, similar or identically acting elements are provided in each case with the same reference numerals. The elements illustrated and their size ratios to one another should not be regarded as being to scale, but rather individual elements, such as for example layers, components, devices and regions, may have been made exaggeratedly large to illustrate them better and/or to aid comprehension. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIGS.  1 A and  1 B  show embodiments of a control element  100  and a vehicle  1000  having a control element  100 . The following description refers equally to  FIGS.  1 A and  1 B . 
     In the embodiment shown, the vehicle  1000  is a motorcycle. In particular, as shown, it may be a conventionally or electrically powered motorcycle such as a motorcycle. Alternatively, the vehicle may be, for example, a trike, a quad bike, or a bicycle. These types of vehicles typically include a steering rod  101 , also referred to as a steering handlebar, as a steering element for steering the vehicle. In the embodiment shown, purely by way of example, the steering element is formed as a control element  100 . The steering rod  101  has handle regions  111  which are embraced or at least touched by the hands of a user, i.e. a vehicle driver, during normal use for driving. 
     As shown in  FIG.  1 A , the control element  100  has at least one piezoelectric component  1  in a tubular section  2 . For this purpose, the control element  100 , i.e. in the shown embodiment the steering rod  101  indicated in  FIG.  1 B , has in the at least one tubular section  2  a cavity  4  at least partially surrounded by a wall  3 . The piezoelectric component  1 , which is arranged in the cavity  4 , is provided and embodied to generate a haptic signal at at least a partial region of the control element  100  and/or to detect an action of pressure on at least a part of the piezoelectric component  1 . 
     The steering rod  101  may preferably be formed as a tube at least in the region of the tubular section  2 , and particularly preferably substantially completely as a tube. In this context, the steering rod may be straight or, as indicated in  FIG.  1 B , slightly bent or formed with bent or kinked sections. Particularly preferably, the tubular section  2  may be the handle portion  111  of the steering rod  101 . In the case of the motorcycle steering rod shown, the handle portion may also be rotatable and thus form a rotatable part of the control element  100 . Corresponding to the two handle regions  111 , the control element  100  may also comprise at least two tubular sections  2  each having a cavity  4  at least partially surrounded by a wall  3 . In at least one or in both of the cavities, at least one respective piezoelectric component  1  is preferably arranged. Alternatively or additionally, at least one tubular section  2  with at least one piezoelectric component  1  can also be present outside the handle regions  111 . 
     In the embodiment shown, the control element  100  has a handle element  5  in each of the handle regions  111 , which surrounds the tubular section  2  with the piezoelectric component  1  and which preferably has a plastic that is softer than the wall  3  of the tubular section  2 . For example, at least the tubular section  2  of the control element  100  may comprise a metal. In particular, the steering rod  101  may comprise a metal. The handle element  5  may comprise or be made of a plastic, for example a rubber, and/or a metal and may be a conventional handle element for a motorcycle or bicycle mounted directly on the steering rod  101 . 
       FIG.  2    shows a further embodiment of a vehicle  1000 , which is a conventionally and/or electrically powered motor vehicle as compared to the previous embodiment. As indicated in  FIG.  2   , the vehicle may be a passenger car. Alternatively, a truck or other vehicle is also possible, which, as shown in  FIG.  2   , has a steering wheel  102  as the control element  100 . 
     The steering wheel  102  has at least one tubular section, which may be formed as explained in connection with  FIG.  1 A  and which has a cavity with at least one piezoelectric component. For example, the steering wheel may be formed as a bent tube at least in the region of the tubular section, and particularly preferably substantially completely as a tube. In particular, the steering wheel may be substantially circular or at least approximate a circular shape. As already described for the steering rod of the preceding embodiment, the steering wheel  102  may, for example, comprise at least two handle regions  111 , each of which is enclosed or at least touched by a hand of the user, i.e. in particular of the vehicle driver, during normal use. Accordingly, the steering wheel may also include at least two tubular sections each having a cavity at least partially surrounded by a wall. In at least one or both of the cavities, a respective piezoelectric component is preferably arranged. Alternatively or additionally, at least one tubular section with at least one piezoelectric component may also be present outside the handle regions  111 . 
     By means of the piezoelectric component integrated in the control element  100 , a driver of a vehicle  1000  can be specifically notified or alerted via a tactile or palpable signal, for example, in a hazardous situation, when parameters are exceeded, or in the case of other messages. Furthermore, the dual functionality of the piezoelectric component can also actively trigger control commands by applying a targeted pressure. 
     For the realization of a haptic feedback, in particular in the handle region  111  of the control elements  100  shown in  FIGS.  1 A to  2   , the piezoelectric component can be operated with a suitable drive signal by which the piezoelectric component  100  undergoes a change in expansion as described in the general part, wherein a pressure can be exerted on at least a part of the tubular section. As a result, the tubular section can be for example at least partially spread, which can preferably also be perceived by a user through the handle element. Due to the piezoelectric component, it can be achieved that the haptic feedback can only act locally in a very defined region of a contact surface to the user. 
     The use of the piezoelectric component makes it possible to use different drive signals in the form of one or more variable parameters, for example voltage, frequency, signal type and/or pulse sequence, which enables the use of different signals for different functions. 
     By applying pressure to the piezoelectric component, the user can generate an electrical signal that can be used to trigger a defined function, such as switching displays and/or accepting or rejecting calls, as well as other functions. 
     As an alternative to the control element for a vehicle in the form of a steering element described in the previous embodiments, the control element  100  can also be formed as another element, in particular, for example, as another control element for a vehicle. For example, the control element may be a brake element, for example a brake lever, and/or a gear selection element, for example a gearshift or a gear shift lever. Furthermore, the control element may also be, for example, an input component, for example a pen-type input component, which may further be used, for example, in connection with a display component, for example in a vehicle. In connection with the figures described below, preferred modifications and further embodiments of the control element  100  are described, which may be, for example, as shown, a control element for a vehicle. Elements and features not described or shown may be embodied as described in preceding embodiments. 
       FIGS.  3 A and  3 B  show, in a perspective view and a sectional view, a preferred embodiment of a piezoelectric component  1  usable in a control element. 
     The piezoelectric component  1  has a piezoelectric actuator  11  and two mechanical amplification elements  13   a ,  13   b . The piezoelectric actuator  11  has a stack of internal electrodes  21  and piezoelectric layers  22  alternately stacked in a stacking direction S. The piezoelectric actuator  11  has a first outer electrode  23  disposed on a first end face  24 , and a second outer electrode  23  disposed on a second end face. The internal electrodes  21  are alternately contacted with one of the first outer electrodes  23  in the stacking direction S. 
     The piezoelectric layers  22  may be, for example, lead zirconate titanate (PZT) ceramics. The PZT ceramics may additionally further include Nd and Ni. Alternatively, the PZT ceramic may additionally further comprise Nd, K, and optionally Cu. Alternatively, the piezoelectric layers  22  may have a composition comprising Pb(Zr x Ti 1-x )O 3 +y Pb(Mn 1/3 Nb 2/3 )O 3 . As an alternative to a piezoelectric ceramic material, for example a piezoelectric polymer may be used. The internal electrodes  21  preferably comprise copper or are particularly preferably made of copper. 
     The piezoelectric actuator  11  is preferably cuboid-shaped as shown. The base surface is defined as a surface whose surface normal points in the stacking direction S. The base surface is rectangular. The longer side of the base surface defines the length L of the piezoelectric actuator  11  and the shorter side of the base surface defines the width B of the piezoelectric actuator  11 . 
     The piezoelectric actuator  11  has a length L between 5 mm and 100 mm and a width B between 2 mm and 8 mm. In a particularly preferred embodiment, for example, the piezoelectric actuator  11  has a length L of 60 mm and a width B of 5 mm. 
     The extent of the piezoelectric actuator  11  in stacking direction S defines the height H of the piezoelectric actuator  11 . The height H of the piezoelectric actuator  11  can be between 200 μm and 3 mm in a particularly preferred embodiment, the height H is 1.8 mm. 
     The actuator  11  has two insulation regions  12 . Each of the insulation regions  12  is formed in an end region of the actuator  11 . In particular, the respective insulation region  12  is formed in the region of an end face  24  of the actuator  11 . 
     In the insulation region  12 , only internal electrodes  21  of one polarity extend to the end face  24  of the actuator  11 . The insulation region  12  can be used for contacting the actuator  11 . For example, the respective insulation region  12  can be provided with the outer electrodes  23  for electrical contacting. 
     The actuator  11  is embodied in such a way that when an electrical voltage is applied, a deformation of the actuator  11  takes place, in particular a change in length in the longitudinal direction R 1  indicated in  FIG.  3 B . In particular, the piezoelectric layers  22  are thus polarized in such a way that the application of an electrical voltage between the internal electrodes  21  leads to a contraction of the actuator  11 , during which the length L of the actuator  11  changes perpendicularly to the stacking direction S. Consequently, there is an expansion of the actuator transverse to the polarization direction and the electric field, which is also referred to as the d31 effect. 
     In order to redirect the effect of the change in length in the stacking direction S, the component has two amplification elements  13   a ,  13   b . When a voltage is applied to the actuator  11 , the amplification elements  13   a ,  13   b  deform at least partially as a result of the change in the extension of the actuator  11 . In particular, the two amplification elements  13   a ,  13   b  are dimensioned and connected to the actuator  11  in such a way that, as a result of a change in the length L of the actuator  11 , a middle region  17   a ,  17   b  of each of the amplification elements  13   a ,  13   b  executes a stroke movement in the stroke direction R 2 , as indicated in  FIG.  3 B , corresponding to the stacking direction S, the amplitude of the stroke movement being greater than the amplitude of the change in the length L of the actuator  11 . 
     As shown, the actuator  11  is preferably arranged between the amplification elements  13   a ,  13   b . The amplification elements  13   a ,  13   b  rest at least partially on the upper side  25  and the lower side  26  of the actuator  11 , respectively. 
     Each of the amplification elements  13   a ,  13   b  is preferably formed in one piece and is strip-shaped and has a rectangular basic shape. Furthermore, each of the amplification elements  13   a ,  13   b  is curved or bent and is bow-shaped. For example, the amplification elements  13   a ,  13   b  each have a sheet metal strip or are made from it, in particular, with or from titanium. 
     Each of the amplification elements  13   a ,  13   b  is divided into several regions or sections. Thus, each amplification element  13   a ,  13   b  has a middle region  17   a ,  17   b . The middle regions  17   a ,  17   b  are connected to respective end regions  18   a ,  18   b  via connecting regions  20   a ,  20   b . The two end regions  18   a ,  18   b  of each of the amplification elements  13   a ,  13   b  rest directly on a surface of the actuator  11 . In other words, the first and second end regions  18   a  of the first amplification element  13   a  rest on a partial region of the top surface  25  of the actuator  11 . Further, the first and second end region  18   b  of the second amplification element  13   b  rest on a partial region of the bottom surface  26  of the actuator  11 . Preferably, the end regions  18   a ,  18   b  are non-detachably connected to the surface of the actuator  11 . In particular, the end regions  18   a ,  18   b  are connected to the surface of the actuator  11  by an adhesive bond  15 . 
     Each of the middle regions  17   a ,  17   b  is spaced from the surface of the actuator  11 . In particular, a free region  16  is located between the respective middle region  17   a ,  17   b  and the bottom side  26  or the top side  25  of the actuator  11 . The free region  16  has a height h. A free height h between the actuator  11  and the respective middle region  17   a ,  17   b  is preferably between 0.2 mm and 5.0 mm and, in a particularly preferred embodiment, is about 3 mm, wherein the free height h indicates the maximum distance between the respective middle region  17   a ,  17   b  and the piezoelectric actuator  11  when no voltage is applied to the actuator  11  and no external force acts on the amplification element  13   a ,  13   b.    
     Preferably, the middle regions  17   a ,  17   b  are formed to run parallel to the surface of the actuator  11 . The connecting regions  20   a ,  20   b  run obliquely to the surface of the actuator  11 . In other words, the respective connecting region  20   a ,  20   b  encloses an angle with the upper side  25  or the lower side  26  of the actuator  11 . The angle is preferably less than or equal to 45°. Thus, the height h of the free region  16  decreases in the direction from the middle region  17   a ,  17   b  towards the end region  18   a ,  18   b  of the respective amplification element  13   a ,  13   b . A total height of the piezoelectric component  1  with the actuator  11  and the two amplification elements  13   a ,  13   b  may be about 9 mm in a preferred embodiment. 
     If an electrical voltage is now applied to the actuator  11 , the partial regions  17   a ,  17   b  of the respective amplification element  13   a ,  13   b  move relative to the actuator  11  in the stroke direction R 2 . In particular, the middle regions  17   a ,  17   b  move in the stroke direction R 2 . In doing so, the amplification elements  13   a ,  13   b  bend at transitions between the middle regions  17   a ,  17   b  and the connecting regions  20   a ,  20   b  and between the connecting regions  20   a ,  20   b  and the end regions  18   a ,  18   b . The amplification elements  13   a ,  13   b  can have at least one thinning, preferably several thinnings, between the respective regions, which allow better deformability of the amplification elements  13   a ,  13   b  and easier execution of the stroke movement. Furthermore, the amplification elements  13   a ,  13   b  can have, for example, embossed structures to increase the strength of individual regions. 
     Movement of the end regions  18   a ,  18   b  in the stroke direction R 2  is prevented by the adhesive bond  15  to the actuator  11 . Instead, the end regions  18   a ,  18   b  move with the actuator  11  in the longitudinal direction R 1 . Thus, a relative movement takes place between the end regions  18   a ,  18   b  and the middle regions  17   a ,  17   b . In a preferred embodiment, a total stroke movement of about 200 μm can be achieved when an electrical voltage of up to 120 V is applied. 
     If a force is applied to the piezoelectric component  1  along the stroke movement R 2 , the amplification elements  13   a ,  13   b  are deformed in such a way that, in particular, the end regions  18   a ,  18   b  are moved away from each other in the longitudinal direction R 1 . By attaching the amplification elements  13   a ,  13   b  to the piezoelectric actuator  11 , the latter is also deformed in the longitudinal direction. As a result, an electrical voltage is generated in the piezoelectric actuator  11 . This voltage can be detected and in this way an action of force can be inferred. For this purpose, the piezoelectric actuator  11  can be connected to a control element, for example a microcontroller or a control unit of the vehicle, which evaluates the electrical voltages generated at the piezoelectric actuator  11 . The piezoelectric actuator  11  can thus be used as a sensor that can detect a force applied by a user. 
     Furthermore, the piezoelectric component  1  can also be used to generate a haptic signal, as described above. When an electrical voltage is applied to the actuator  11 , the piezoelectric actuator  11  deforms in the longitudinal direction R 1  and the amplification elements  13   a ,  13   b  accordingly perform the described stroke movement. By applying an AC voltage, a vibration can be generated accordingly, which can be transmitted to the tubular section of the control element and perceived by a user. 
       FIGS.  4 A to  4 C  show an embodiment of a control element  100  in which the piezoelectric component  1  described above is used. The control element  100  may, for example, be a control element for a vehicle as described further above.  FIGS.  4 A to  4 C  show a perspective view and two sectional views of a part of the control element  100 . In particular, the tubular section  2  in which the piezoelectric component  1  is arranged is shown. The tube axis of the tubular section  2  extends in the direction  91  indicated in  FIGS.  4 A to  4 C , and the tube cross-section lies in the plane spanned by directions  92  and  93 . A possible handle element mounted on the tubular section  2 , such as shown in  FIG.  1 A , is not shown in  FIGS.  4 A to  4 C  or in the following figures for the sake of clarity. 
     The piezoelectric component  1  is arranged in the tubular section  2  such that the longitudinal direction of the piezoelectric actuator is along the tube axis of the tubular section. In such a longitudinal arrangement, as shown, a piezoelectric component  1  can be used which has a linear expansion much larger than a diameter of the tubular section  2 . 
     Furthermore, the control element  100  comprises at least one interaction element  6  through which a user can cause an action of pressure on the piezoelectric component  1  and/or to which the piezoelectric component  1  can transmit the haptic signal for forwarding to the user. In particular, the piezoelectric component  1  may act on the interaction element  6  by the stroke movement described above. Furthermore, the interaction element can transmit a pressure caused by a user on the interaction element  6  to the piezoelectric component  1  so that the action of pressure can be detected by the piezoelectric component  1  by generating an electrical signal in the piezoelectric component  1 . In this case, the interaction element  6  can form a button that can be actuated by the user, by means of which a specific function can be triggered. 
     In the embodiment shown, the interaction element  6  is in the form of a button or a plunger and is arranged or attached to an amplification element of the piezoelectric component  1 . The interaction element is partially arranged in an opening  62  in the wall  3  of the tubular section  2  and extends into the cavity  4 . Due to the stroke movement of the piezoelectric component  1 , the interaction element  6 , which in the rest position prior to the stroke movement may be recessed in the opening or may also be arranged protruding from the opening, can be pressed (further) out of the opening  62  and thus cause a perceptible haptic signal for a user. Conversely, in a rest position, the interaction element  6  may protrude from the opening  62  and be pressable by a user towards the piezoelectric component  1 . 
     The control element  100  further comprises a support element  7  on a side of the piezoelectric component  1  facing away from the interaction element  6 . Thus, the piezoelectric component  1  is arranged between the interaction element  6  and a back side region  63  of the wall  3  opposite the interaction element  6 , as viewed from the piezoelectric component  1 . The support element  7  is thus arranged between the piezoelectric component  1  and the back side region  63  of the wall  3  in the cavity  4  of the tubular section  2 . As shown, the support element  7  has a bearing surface  71  for the piezoelectric component  1 , with which the piezoelectric component  1  can be supported against the support element  7 . On a side opposite to the bearing surface  71 , the support element  7  has a support surface  72  which nestles against the back side region  63 . The support element  7  allows the stroke movement of the piezoelectric component  1  to be directed completely in the direction of the interaction element  6 . 
     As shown, the tubular section  2  of the control element  100  may have a round, in particular a circular, tubular cross-section. In addition, however, other cross-sectional shapes are also possible, since in particular the shapes of the support element  7  and the interaction element  6  can be easily adapted to other tubular cross-sections. 
       FIGS.  4 A to  4 C  thus show a unilaterally movable concept of the piezoelectric component  1  within the control element  100 , which allows a unilateral use of the actuator movement. In particular, only the interaction element  6  moves against the tubular section  2 , while the opposite side is completely blocked in the back side region  63 . This leads to the effect that the deflection of the interaction element is maximized. The interaction element  6  and/or the support element  7  can each be with or made of a plastic, preferably a hard plastic, or with or made of a metal, in order to be able to transmit the forces of the piezoelectric component  1  to a user or vice versa as effectively as possible. 
     In the figures below, directions  91 ,  92 ,  93  are also shown for clarity. 
     As can be seen in  FIG.  5    according to a further embodiment, the wall  3  can have an interaction region  31  which forms the interaction element or at which an interaction element  6  described above is arranged within the cavity  4  of the tubular section as shown. In this case, the wall  3  does not have an opening and the transmission of the haptic signal or the action of pressure takes place at least partially via the interaction region  31  of the wall. Thus, the piezoelectric component can exert a force on the interaction region  31  of the wall in the tubular section when the haptic signal is generated, either directly or as shown via the interaction element  6 . In this regard, it may be advantageous if the wall  3  has greater mechanical deformability in the interaction region  31  than in other regions so that the interaction region  31  may have sufficient flexibility, for example, to transmit a haptic signal to a user. For example, as indicated, the wall may be thinner in the interaction region  31  than in other regions and/or surrounded by an indentation around the interaction region. 
     As shown in  FIGS.  6  and  7   , a plurality of piezoelectric components  1  may also be arranged in the tubular section  2 , wherein the piezoelectric components  1  may be the same or different in terms of their technical design and/or functionality. For example, the plurality of piezoelectric components  1  may be arranged side by side to form an array as shown. Each of the piezoelectric components  1  may, for example, be read out and/or controlled separately from the remaining piezoelectric components. This allows different piezoelectric components  1  to perform different functions. Alternatively, several piezoelectric components  1  can be read out or driven together, so that the functionality can be multiplied compared to a single piezoelectric component  1 . The piezoelectric components  1  could, for example, be arranged in a partial region of the handle region or also distributed over the handle region. Thus, interactions with a user can be possible at different positions. 
     As indicated in  FIG.  6   , the piezoelectric components  1  may be placed in a longitudinal arrangement in the tubular section. As shown in  FIG.  7   , the piezoelectric components  1  can also be arranged in the tubular section  2  in such a way that the longitudinal direction of the piezoelectric actuators is transverse to the tube axis of the tubular section  2 . In this transverse arrangement, several piezoelectric components  1  can be placed close together along the tube axis so that the piezoelectric components can, for example, together simulate the function of a slider. 
       FIGS.  8 A to  8 C  show another embodiment of a control element  100 , with views corresponding to those of  FIGS.  4 A to  4 C . Compared to the embodiment of  FIGS.  4 A to  4 C , the piezoelectric component  1  is arranged between two interaction elements  6 . The interaction elements  6 , each of which is arranged as a button or plunger in a respective opening  62  of the wall  3  as shown, can be arranged radially opposite one another, in particular with respect to the tube cross section. Compared to the embodiment of  FIGS.  4 A to  4 C , this concept allows deflections in opposite directions and thus interaction in both directions with a user. 
     The features and embodiments described in connection with the figures can be combined with each other according to further embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in connection with the figures may alternatively or additionally have further features according to the description in the general part. 
     The invention is not limited by the description based on the embodiments to these embodiments. Rather, the invention includes each new feature and each combination of features, which includes in particular each combination of features in the patent claims, even if this feature or this combination itself is not explicitly explained in the patent claims or embodiments. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  piezoelectric component 
               2  tubular section 
               3  wall 
               4  cavity 
               5  handle element 
               6  interaction element 
               7  support element 
               11  piezoelectric actuator 
               12  insulation region 
               13   a  amplification element 
               13   b  amplification element 
               15  adhesive bond 
               16  free region 
               17   a ,  17   b  middle region 
               18   a ,  18   b  end region 
               20   a ,  20   b  connection region 
               21  internal electrode 
               22  piezoelectric layer 
               23  outer electrode 
               62  opening 
               63  back side region 
               71  bearing surface 
               72  support surface 
               91 ,  92 ,  93  direction 
               100  control element 
               101  steering rod 
               102  steering wheel 
               111  handle region 
               1000  vehicle 
             B width 
             h height 
             H height 
             L length 
             R 1  longitudinal direction 
             R 2  stroke direction 
             S stacking direction