Abstract:
An actuator for operating the foot pedals of a motor vehicle with the aid of a servomotor. The actuator has two actuating arms which can be alternatingly actuated by selecting the direction of rotation of the servomotor. First and second coupling elements in the form of, respectively, an eccentric device and a pin projecting radially away from the motor shaft are provided to produce this alternating action on either actuating arm. It is thus possible to selectively actuate either the brake pedal or the gas pedal, for example, of a motor vehicle with a mutual device which makes only minimal demands on space and is cost-effective.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to an actuator for operating the foot pedals of a motor vehicle with the aid of a servomotor.  
           [0002]    In the course of functional and fatigue testing of a motor vehicle, it is customary to have appropriate robots perform the pedal and steering wheel movements, so that movement sequences of these devices are generated which correspond to a large extent to the actual sequences of the operation of the motor vehicle. As a rule, such devices consist of frames with arms that are hinged to each other in a lever-like manner and create these typical movements, and of actuating elements, which act on the respective operating elements, for example the gas pedal, and create the desired movement sequences.  
           [0003]    Devices for operating at least one foot pedal, either the gas pedal or the brake pedal, are known from DE 39 40 588 A1 or EP 0 235 333 B1, which describe the arrangement of a drive robot on the driver&#39;s seat. Hydraulically or pneumatically operating actuating elements are provided for operating the pedals, which require solid anchoring and support.  
           [0004]    Only limited space is available in the lower area of the motor vehicle for the drive and actuating devices for performing the automatic operation of the gas pedal, the brake pedal and the clutch pedal, so that it is necessary to make optimal use of the available space.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides an actuator that can selectively operate either the brake pedal, the clutch pedal, or the accelerator, or gas, pedal of a motor vehicle, has minimum space requirements and is cost-effective.  
           [0006]    For this purpose, the invention provides an actuator for operating foot pedals of a motor vehicle, the actuator comprising: a servomotor having a motor shaft that is selectively rotatable in either one of two senses; and two actuating arms coupled to the servomotor, each actuating arm being adapted to operate a first one of the vehicle foot pedals in response to rotation of the motor shaft in a first one of the two senses and to operate a second one of the vehicle foot pedals in response to rotation of the motor shaft in a second one of the two senses.  
           [0007]    The idea on which the invention is based resides in that either an actuating arm for one pedal or an actuating arm for another pedal is actuated, depending on the selection of the direction of rotation of the servomotor, so that a single common servomotor suffices for actuating two pedals.  
           [0008]    In accordance with advantageous embodiments of the invention, first and second coupling elements, each in the form of an eccentric device and of a pin radially projecting away from the motor shaft, are provided, which cause this alternating action on respectively one actuating arm or the other.  
           [0009]    A preferred exemplary embodiment of the invention will now be described in greater detail, making reference to the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    FIGS.  1  to  3  are perspective basic representations of an actuator according to the invention, in the full braking position, viewed from three different directions.  
         [0011]    [0011]FIG. 4 is a perspective view of an actuator according to the invention in the basic position.  
         [0012]    [0012]FIG. 5 is a top view of the actuator of FIG. 4.  
         [0013]    [0013]FIG. 6 is a bottom view of the actuator of FIG. 4.  
         [0014]    [0014]FIGS. 7 and 8 are cross-sectional views taken along lines  7 - 7  and  8 - 8 , respectively, of FIG. 6.  
         [0015]    FIGS.  9  to  13  are views corresponding to those of FIGS.  4 - 8 , respectively, showing the actuator in the full braking position.  
         [0016]    FIGS.  14  to  18  are views corresponding to those of FIGS.  4 - 8 , respectively, showing the actuator in the full throttle position.  
         [0017]    [0017]FIGS. 19 and 20 are perspective representations of an embodiment of an actuator with a pedal arrangement.  
         [0018]    [0018]FIGS. 21 and 22 are partial representations of an embodiment of an actuator with an associated clutch actuator. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    The basic structure of an actuator according to the invention is shown in FIGS. 1, 2 and  3 , which illustrate the actuator, in perspective views from three different directions, in the full braking position. A first actuating arm  20  with an actuating element  24  for a first foot pedal is in an operating, or active, position, while a second actuating arm  30  with an actuating element  34  rests in an inactive position. The actuating arms  20  and  30  are respectively hinged on a first pivot shaft  12  and on a second pivot shaft  13 , which are mounted in parallel with a motor shaft  11  in a support plate of a housing of a servomotor  10 . Only the structurally important elements are represented in FIGS.  1 - 3 , i.e. those elements required for performing the actuating movements, but not those elements which are required for structural purposes for the mechanical reinforcement or optimization of the mechanical structure. Such elements can vary, depending on the layout of the actuator and are not the subject of the invention.  
         [0020]    Two eccentric devices or eccentric cams  22  and  32  are seated on the motor shaft  11  and constitute first coupling elements. During rotation of the motor shaft  11  by the servomotor  10 , one or the other of devices  22 ,  32  is acted upon in such a way as to produce a force coupling with the associated actuating arm  20  or  30  in the sense that pivoting of the associated eccentric device  22 ,  32  results in pivoting out of the associated actuating arm  20 ,  30 . Here, their shape and their hinged attachment to the first and second pivot shafts  12  and  13  is defined in such a way that the pivot movement of the actuating element  24  or  34 , required for the actuation of the respectively associated foot pedal, is performed by means of the rotary movement of the respective eccentric device  22 ,  32 .  
         [0021]    Here, the basic idea lies in that the coupling of the eccentric devices  22 ,  32  to the motor shaft  11  depends on the direction of rotation of the servomotor  10 . In this case, starting from a neutral position, motor shaft  11  is rotated either toward the right (clockwise) or to the left (counterclockwise), as viewed from the left-hand end in FIG. 1, depending on which of the actuating elements  24  or  34  is intended to perform an actuating movement for operating the foot pedal associated with it.  
         [0022]    To achieve this, second coupling elements, here constituted by pins  21 ,  31  (see FIGS. 7 and 8) radially projecting away from the motor shaft  11 , are provided. Each of pins  21 ,  31  acts together with a respective stop  22 A,  32 A, respectively, attached to an associated eccentric device  22  or  32 , depending on the direction, or sense, of rotation of shaft  11 , in such a way that during rotation in a first, clockwise, direction of rotation the first pin  21  acts on the stop  22 A in the eccentric device  22 , but the second pin  31  in the eccentric device  32  is moved away from its associated stop  32 A into a space in which the rotation of the second pin  31  can take place without acting on its associated eccentric device  32  as the associated second coupling element.  
         [0023]    A rotation of the motor shaft  11  out of the neutral position in a counterclockwise direction correspondingly leads to the second pin  31  now acting on its associated stop  32 A in the eccentric device  32  as the second coupling element and therefore results in the extension of the second actuating arm  30  and of the associated actuating element  34  for the actuating movement on the second foot pedal.  
         [0024]    The details of this coupling in the individual operating positions of the actuator are schematically sketched in FIGS. 7, 8,  12 ,  13  and  17 ,  18 , each of which represents a cross section through the actuating plane of the first actuating arm  20  or of the second actuating arm  30 . The respective cross section planes are shown in FIGS. 6, 11 and  16 .  
         [0025]    It should be noted here that the shape of the two actuating arms  20  and  30  and their hinging on the pivot shafts have been selected to be different from one another because the opposite movements of the two eccentric devices  22  and  32  must lead to a movement in the same direction of the associated actuating element  24  or  34  in order to achieve the movement, correspondingly in the same direction, for actuating the two foot pedals. Not only are toggle levers  25  and  35  used for this, but also the intermediate pieces and hinge arms shown in the drawings, by means of which the toggle levers  25  and  35  and also the actuating elements  24  and  34  are hinged on the pivot shafts  12  and  13 .  
         [0026]    The mutual action of the individual components will now be explained with reference to a movement sequence with the activation of the two actuation elements  24  and  34  taking place sequentially:  
         [0027]    The point of departure is the neutral position, represented in FIGS.  4  to  8 , of the actuator, wherein the two pins  21  (FIG. 7) and  31  (FIG. 8) on the motor shaft  11  are on respectively different sides of their associated stops  22 A,  32 A, and the two actuating elements  24  and  34  take up their neutral position, as is also represented for the actuating element  34  in FIGS.  1  to  3 .  
         [0028]    If the servomotor  10  is turned in a counterclockwise direction, the first pin  21  acts on its associated stop  22 A in the eccentric device  22  (arrow P 1  in FIG. 12), whereupon stop  22 A is pivoted and extends the first actuating arm  20  out of its neutral position into the full braking position, represented in FIG. 1 and in FIGS.  9  to  13 , i.e. performs the actuating process by means of which the brake pedal is moved, depending on the angle of rotation of the servomotor  10 , or the motor shaft  11 . A restoring spring (not represented) is tensed in the course of this actuating movement. During this movement in a counterclockwise direction (arrow P 2  in FIG. 13), the second pin  31  moves away from its associated stop  32 A and therefore does not act on its associated eccentric device  32 . As a result the second actuating arm  30  remains in its neutral position, also represented in FIGS.  1  to  3 .  
         [0029]    When the actuating process (braking) is terminated, the servomotor  10 , or the motor shaft  11 , turns in a clockwise direction back into the neutral position, i.e. the first pin  21  moves away from its associated stop  22 A (FIG. 12), whereupon the first actuating element  24  is moved back into its neutral position because of the action of the restoring spring assigned to it, and therefore the neutral position of the actuator represented in FIGS.  4  to  8  is achieved.  
         [0030]    If a rotation of the shaft  11  in a clockwise direction takes place (arrows P 3  and P 4  in FIGS. 17, 18), the second pin  31  acts on its associated stop  32 A on the eccentric device  32 , and the same process is performed for the second actuating arm  30 , i.e. now the second actuating element  34  is extended because of the tension of its associated restoring spring and actuates the gas pedal, while the first pin  21  turns away from it&#39;s associated stop  22 A and the first actuating arm  20  remains in its neutral position. Here, too, the return of the actuating element  34 , or of the second actuating arm  30 , by means of the restoring spring  33  into the neutral position of the actuator represented in FIGS.  4  to  8  takes place following the return movement of the motor  10 , or the motor shaft  11 , into the neutral position.  
         [0031]    Only the actuator itself is represented in FIGS.  1  to  18 , i.e. a device which generates an actuating movement through its actuating elements  24 ,  34 , the geometry and the kinematic sequence of which approximately correspond to the actuating sequence of a foot pedal (gas or brake pedal) of a motor vehicle.  
         [0032]    For the purpose of a more flexible adaptation to the individual circumstances in the lower area of the motor vehicle between the pedals and the driver&#39;s seat, FIGS. 19 and 20 represent a further development of the solution in accordance with the invention, wherein the actuator is coupled with a pedal arrangement  40 , which has pedals  41 ,  42  and  43 , which then directly act on the respectively associated pedals of the motor vehicle. This pedal device  40  consists of a mounting plate  44 , which is pivotably connected by means of shafts M 1  to M 2  with support arms  55 ,  65 , wherein the support arms  55  and  56  are structurally embodied in such a way that they can be fastened on the actuator on both sides of the two actuating arms  20  and  30 , or are formed as support plates, for example, by appropriately shaped components of the actuator itself.  
         [0033]    In the exemplary embodiment represented in FIGS. 19 and 20, the three pedals  41 ,  42 ,  43  are hinged by means of a common shaft M 3  to M 4  to the mounting plate  44 , so that the pedals can be tilted out of a position of rest (pedals  42  and  43  in FIG. 19) into their actuating position (pedal  41  in FIG. 19). In this actuating position the upper end of a pedal is connected by means of a connecting element  50 ,  60  with the associated actuating element  24 ,  34  of the actuator. Each connecting element  50  and  60  is embodied in two parts in such a way that a tilt shaft M 7 , M 8  (FIG. 20) is formed in addition to the pivot shaft M 5  to M 6  and extends through the upper end of the associated actuating elements  24 ,  34 . The two parts  61  and  62 , or  51  and  52 , of the connecting elements  50 ,  60  are preferably also designed to be longitudinally displaceable so as to preset the initial positioning of a pedal  41 ,  42 ,  43  on the foot pedal of the motor vehicle assigned to it.  
         [0034]    Thus, in FIG. 19 the pedal  41 , which is used for actuating the gas pedal of the motor vehicle, is connected by means of the connecting element  60  with the upper end of the actuating element  34 , which is in a neutral position. If now the servomotor  10  performs the actuating movement described above, the actuating element  34  is pivoted, for example into the position represented in FIG. 14 and, via the connecting element  60 , takes the pedal  41  along which, after appropriate calibration, actuates the gas pedal of the motor vehicle in the intended manner and with the intended force (arrow in FIG. 19).  
         [0035]    [0035]FIG. 20 shows the assembly of the actuator and the pedal device in a compact state, in which it has been optimized, in particular for transport and installation in the lower area of the motor vehicle.  
         [0036]    The connecting elements  50 ,  60 , as well as the pedals  41  to  43  and the entire mounting plate  44  have been folded into a compact unit along the axes represented in FIG. 20, wherein the connecting elements  50  and  60  come to rest above the actuator, and the mounting plate  44  with the pedals  41  to  43  folded on it are in an approximately vertical position in front of the actuator. The entire unit of actuator and pedal arrangement is introduced into the lower area of the motor vehicle while in this assembly position, the mounting plate  44  is then flipped down on the floor of the motor vehicle, the pedals  41  to  43  are flipped up, and the connecting elements  50  and  60  are folded out and their front ends are coupled with the upper ends of the associated pedals, so that the frictionally connected coupling between the actuator on the one side and the pedal  41 , shown for use with the gas pedal in FIG. 19, on the other side, is formed. Only the coupling of the pedal  41  for the gas pedal is represented in FIG. 19 for reasons of simplifying the drawing. However, it can be clearly seen that such a frictional connection for actuating the brake pedal can also be provided by flipping the pedal  42  up and pivoting the connecting element  50  out, so that then, by means of the rotation of the servomotor  10  in a clockwise or counterclockwise direction, as described earlier herein, either the pedal  41  (for the gas pedal) or the pedal  42  (for the brake pedal) is actuated.  
         [0037]    The pedal arrangement  40  represented in FIGS.  19  to  22  has three pedals, in particular also a pedal  43  on the left side, viewed in the driving direction, for actuating the vehivle clutch pedal. To make this possible, the actuator in accordance with the invention for actuating the gas pedal and the brake pedal can be complemented by a clutch actuator  70 . The clutch actuator  70  has an additional servomotor  73 , which acts via an actuating linkage  72  on a connecting element  71 , which is essentially constructed identically to the connecting elements  50  and  60  and which, following the attachment to the pedal  43  (FIG. 22), can act on the clutch pedal via the actuating linkage  72 . In order to make the connection of the clutch actuator  70  clear, the actuator which has already been described in detail above is only rudimentarily shown. The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.  
         [0038]    Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation.