Patent Publication Number: US-2022230790-A1

Title: Control element

Description:
The invention relates to a control element that is preferably used in a vehicle, in particular a motor vehicle, rail vehicle, aircraft, or boat. 
     There are numerous control elements in vehicles that can easily distract a driver when operated. This can result in undesired reactions or even the risk of an accident. 
     Based on this, the fundamental object of the invention is to create a control element that distracts the diver as little as possible. 
     This object is achieved by a control element comprising a magnetorheological material, which has at least one drive assembly for generating a variable magnetic field. 
     This object is achieved entirely in this manner. 
     According to the invention, a change in a magnetic field can generate a change in the feel of the control element. This can be achieved in particular by a change in the shape of the control element and/or by a change in the stiffness of the control element. In this manner, communication with a user of the control element can be established, without the user having to look at the control element itself, and thus becoming distracted. 
     The magnetorheological material can be a magnetorheological elastomer or a magnetorheological fluid. A magnetorheological elastomer contains magnetorheological material dispersed in the elastomer. This is usually carbonyl iron powder, which is homogenously dispersed in the elastomer. For special applications, the magnetorheological material can also be dispersed with a specific texture. 
     Under the effects of a magnetic field, the magnetorheological elastomer aligns itself with the direction of the field. If the magnetorheological elastomer forms the core of a coil, for example, the magnetic field results in a lengthening in the longitudinal direction of the coil, or a cross section reduction in the transverse direction of the coil. The shape therefore changes in a manner that the user feels. 
     If the magnetorheological material is a magnetorheological fluid, this material is then sealed into a hollow chamber in an elastomer. A change in the magnetic field only results in a change in the viscosity, and therefore the stiffness, of the switching element, but not in a change in shape. This change in stiffness can also be felt by a user. 
     According to another embodiment of the invention, the drive assembly is designed to generate a vibration in the control element, in particular with different frequencies that can be distinguished by the user, or for different lengths of time and/or intermittently. 
     The user can be notified in this manner by a vibration indicating that an input has been entered correctly. 
     By way of example, a user can be notified by a vibration if an input has been entered correctly, e.g. a telephone number has been input. Different frequencies can also indicate to the user whether an input is for increasing a specific value or decreasing a specific value. Different frequencies can also be used to provide a user with specific feedback, or specific requests for an input. In a similar manner, different lengths of time, and/or intermittent outputs, of a frequency can be used to communicate with a user. 
     According to another embodiment of the invention, the drive assembly is configured to allow at least a part of the control element to protrude from or retract into a surface when it is activated. 
     In this manner, the control element can then retract into a surface when it is not needed, for example, and only protrude when an input is needed. 
     The control element is preferably in the form of a push key or button. 
     According to another embodiment of the invention, the control element comprises numerous individual control elements, each of which has its own drive assembly. 
     In this manner, an entire input panel can be obtained, e.g. for inputting a telephone number. 
     According to another embodiment of the invention, the operating element contains a magnetorheological elastomer that is coupled to a coil for generating a variable magnetic field, wherein the coil is coupled to an electrical switching device, and is coupled at least at one end to an element of the drive assembly that can be moved manually via a connector, wherein the switching device contains means for monitoring the magnetic field and/or capacitance between the two connectors in order to trigger a switching procedure when the element that can be moved manually is activated. 
     The control element is combined with an electric switching device in this manner. The control element is thus simple and compact, forming a switching device as well as a variable feel for communicating with a user. 
     A control element according to the invention can preferably be produced with 3D printing. 
     Almost any shape can be obtained with 3D printing, such that the control element can be readily adapted to different applications and requirements. 
     As specified above, a control element according to the invention can preferably be used to communicate with a user, which is obtained by a change in the feel of the control element that can be felt by a user. A vibration can be used for this, to give a user feedback regarding the activation of the control element, or to request an input from a user. 
     As specified above, a control element according to the invention can preferably be used in a vehicle, in particular a motor vehicle, rail vehicle, aircraft, or boat. 
     It should be understood that the features of the invention specified above and explained below can be used, not only in the respective combinations that are given herein, but also in other combinations or in and of themselves, without abandoning the scope of the invention. 
    
    
     
       Further features and advantages of the invention can be derived from the following description of preferred exemplary embodiments in reference to the drawings. Therein: 
         FIG. 1  shows a schematic illustration of a control element according to the invention, which has a magnetorheological elastomer; 
         FIG. 2  shows a schematic illustration of a second embodiment of a control element according to the invention, which has a magnetorheological fluid; 
         FIG. 3  shows a schematic illustration of a control element according to the invention, composed of numerous magnetorheological individual elements; 
         FIG. 4  shows a partial view of a control element according to the invention, recessed into a surface in the inactive state; 
         FIG. 5  shows a view of the control element according to  FIG. 4  in the activated state, protruding in part from the surface; 
         FIG. 6  shows a schematic illustration of a control element composed of nine individual elements, wherein each individual element also contains a switch element; 
         FIG. 7  shows an enlarged depiction of another embodiment of a control element according to the invention, which can be used as an electrical switching element, and also contains a magnetorheological elastomer for communicating with the user by changing the feel thereof. 
     
    
    
     A schematic illustration of a control element according to the invention is indicated as a whole with the numeral  10  in  FIG. 1 . This is a control element  10  that has a magnetorheological elastomer  12  in the form of a block surrounded by a coil  15 . 
     The magnetorheological elastomer  12  contains magnetizable particles that are dispersed in the elastomer matrix. This is usually carbonyl iron powder that is homogenously dispersed in the elastomer matrix. A texture can also be provided for special applications. 
     When an external magnetic field is applied, the magnetizable particles are reversibly magnetized in the magnetic field. This results in a change in shape, which can result in a change in length, i.e. a lengthening, as indicated by the arrows  23  and  24 , as well as a corresponding reduction in the cross section. The stiffness of the magnetorheological elastomer  12  can also change. A drive assembly  14  comprises a coil  15 , a power source, and a switch  22 . 
     The power source  20  and the switch  22  can preferably be controlled electronically. The coil can be an annular coil in a cylindrical, elongated shape, within which the magnetorheological elastomer  12  is enclosed. It should be understood that a variety of other coils can also be used. 
     It should be understood that the magnetorheological elastomer  12  does not have to be in the shape of a block, but instead can take nearly any arbitrary shape, which can be readily obtained with 3D printing. By way of example, it can be a hollow structure, or a structured hollow structure containing identical or different individual elements. 
       FIG. 2  shows a variation on the embodiment shown in  FIG. 1 , and is indicated as a whole with the numeral  10   a . The same reference symbols are used for the same elements in the other figures as well. 
     Instead of a magnetorheological elastomer, this embodiment contains a magnetorheological fluid  13 , which is sealed into a hollow chamber in an elastomer. This construction also corresponds to the assembly in  FIG. 1 . 
     Under the effect of a magnetic field, only the stiffness of the control element  10   a  is changed, while its shape remains the same. 
     The control element  10  or  10   a  in  FIG. 1  and  FIG. 2  respectively, can be part of a switching element with which an electric switch is actuated. The control element  10  or  10   a  can therefore be part of a mechanical tappet, with which an electric switch is actuated. The drive assembly  14  is used to generate a variable feel through a change in the shape and/or stiffness of the elastomer  12 , which can be felt by a user. 
     As a result, a user can be given feedback as to whether the control element has been actuated correctly to execute a specific input. Furthermore, the elastomer can be caused to vibrate, wherein different frequencies, lengths of time, and/or an intermittent output can be used to exchange certain information with the user. 
     The control element can also be composed of numerous individual elements, as is shown schematically in  FIGS. 3 and 6 . 
     The control element  10   b  in  FIG. 3  is composed, by way of example, of nine individual control elements  26 ,  27 ,  28 ,  29 ,  30 ,  31 , 32 ,  33 , and  34 , arranged in the manner of a chess board. Each individual control element  26  to  34  has its own drive assembly  35 ,  36 ,  37 ,  38 ,  39 ,  40 ,  41 ,  42 ,  43  that has a coil that can be activated individually (connectors not shown). 
     In this manner, larger input panels can be obtained, e.g. like those for a telephone keypad. A switching procedure can be obtained with each individual control element  26  to  34 , and communication with a user can take place in that a change in the shape or stiffness, and thus in the feel, is obtained that can be felt by a user. 
     Another embodiment of a control element according to the invention is shown in  FIGS. 4 and 5 , indicated as a whole with the numeral  10   c . This control element  10   c  is recessed in a surface  45 , and can move therein. When it is activated, as indicated by way of example in  FIG. 5 , part of the control elements  10   c ′ protrude from the surface  45 . 
       FIG. 6  shows another control element, indicated as a whole with the numeral  10   d , which is also composed of nine individual control elements  26  to  34  arranged in the manner of a chess board. 
     Each of the individual control elements  26  to  34  also contains a switch element  47 , which triggers an electric switching procedure when activated manually. Depending on the predefined structure thereof, there is a specific pressure point characteristic in the inactive state, through which a switching procedure can be triggered when actuated manually (fail-safe operation). In the activated state, this switching characteristic can be altered, and communication with the user can be established as described above. 
     Another control element is shown by way of example in  FIG. 7 , indicated as a whole with the numeral  10   e . This is a control element with which an electrical switching element  50  is obtained, and which is combined with a magnetorheological elastomer  12  to generate a variable feel. 
     The coil  15  is connected at a first end, via a flat connector  16 , to the magnetorheological elastomer  12 , which contains a protruding switch element  47 . 
     The coil  15  is connected at its other end to the drive assembly  14  via a connector  18 . 
     A switching device  50  is interconnected between the two connectors  16 ,  18 . The switching device  50  contains an electronic monitor that registers a change in the magnetic field and/or the capacitance between the two connectors  16 ,  18  when the switch element  47  is depressed manually. This triggers a switching procedure that results in a switching between the two connectors  52 ,  54 . 
     REFERENCE SYMBOLS 
     
         
         
           
               10 ,  10   a ,  10   b ,  10   c ,  10   d ,  10   e  control element 
               12  elastomer 
               13  magnetorheological fluid 
               14  drive assembly 
               15  coil 
               16  first connector 
               18  second connector 
               20  power source 
               22  switch 
               23  arrow 
               24  arrow 
               26  individual control element 
               27  individual control element 
               28  individual control element 
               29  individual control element 
               30  individual control element 
               31  individual control element 
               32  individual control element 
               33  individual control element 
               34  individual control element 
               35  individual drive assembly 
               36  individual drive assembly 
               37  individual drive assembly 
               38  individual drive assembly 
               39  individual drive assembly 
               40  individual drive assembly 
               41  individual drive assembly 
               42  individual drive assembly 
               43  individual drive assembly 
               45  surface 
               47  switch element 
               50  switching device 
               52  connector 
               54  connector