Abstract:
A robot includes a movable robot arm, at least one actuator for moving the robot arm, and a tool attached to the robot arm for adjusting the track of a wheel by turning of a track rod of a motor vehicle. The tool includes a tool head and a tool handle connecting the tool head to the robot arm. The tool head has a slot-shaped opening in a distal end, which is remote from the robot arm, for introducing a track rod with a thickness that is less than or equal to 20%, and preferably less than and equal to 15% of the tool head from the distal end to the connection to the tool handle.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to German Patent Application No. 202015008713.2, filed Dec. 18, 2015, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a robot with a tool for tie rod adjustment. 
       BACKGROUND 
       [0003]    The steered wheels of motor vehicles each exhibit a tie rod for steering. The track of the wheels, i.e., the alignment of the two steered, opposing wheels on the motor vehicle, can be adjusted by turning a tie rod. It is here required that the two wheels be aligned parallel to each other. A hexagon is formed on the tie rod, and this hexagon can be used to apply a torque to the tie rod in order to turn the tie rod and change the track of the wheel allocated to this tie rod. A threaded section of the tie rod exhibits an external thread, and this external thread is screwed onto a bearing head with an internal thread, as a result of which turning the tie rod changes the track of the wheel. The bearing head is normally fastened to a steering arm for swiveling the steered wheel. 
         [0004]    Before turning the tie rod, it is first necessary to loosen a lock or counter nut, and then turn the tie rod to change the track, after which the lock nut must again be tightened so that the correspondingly changed track remains unchanged during motor vehicle operation. 
         [0005]    Known from U.S. Pat. No. 8,082,822 B2 is a robot with a movable robot arm. A tool for setting the track of a wheel is fastened to the robot arm. The tool encompasses a first mechanical actuating member for turning the tie rod, and a second mechanical actuating member for turning the lock nut. 
       SUMMARY 
       [0006]    The object of the invention is to provide a robot with a tool for tie rod adjustment in which the tie rod can be easily set, wherein the tool is inexpensive to manufacture. 
         [0007]    In an embodiment, this object is achieved in a robot comprising a movable robot arm, at least one actuator for moving the robot arm, a tool fastened to the robot arm for setting the track of a wheel by turning a tie rod of a motor vehicle, wherein the tool encompasses a tool head and tool shaft, which joins the tool head with the robot arm, wherein the front end of the tool head remote from the robot arm exhibits a slotted opening for introducing a tie rod as well as a thickness d, wherein the thickness d measures at most about 20%, preferably at most 15%, of the length  1  of the tool head from the front end to where connected to the tool shaft. In other words, the tool head is an approximately disk-shaped part, which based on its outer geometry can, guided by the robot arm, be introduced into the narrow, poorly accessible part of a motor vehicle in which the tie rod is mounted. 
         [0008]    In an embodiment, the tool encompasses a first mechanical actuating member that can be turned around a first rotational axis for turning the tie rod, and a second mechanical actuating member that can be turned around a second rotational axis for turning a lock nut on the tie rod, wherein the first mechanical actuating member exhibits a first contact surface for placement on a positive geometry of the tie rod, wherein a main part of the first contact surface of the first mechanical actuating member is fixed in design in terms of a radial movement relative to the remaining tool and/or relative to the first rotational axis. The first contact surface of the first mechanical actuating member forms a counter-positive geometry, and the geometry of the first contact surface is essentially designed complimentarily to the geometry of a positive geometry on the outside of the tie rod. As a result, a torque can be positively applied from the first contact surface of the main part to the positive geometry on the tie rod. A main part, meaning a greater part, of the first contact surface can here not be moved radially relative to the first rotational axis as a longitudinal axis of the first mechanical actuating member. As a result, the first mechanical actuating member can advantageously be built and fabricated in an especially easy manner from a structural standpoint, in addition to which the torque can be especially reliably transferred from the first actuator, i.e., the first contact surface on the first mechanical actuating member, to the positive geometry on the tie rod during robot operation. Turning involves a rotational movement around a rotational axis. 
         [0009]    In an additional embodiment, the first mechanical actuating member and second mechanical actuating member are built into just a single tool. As a rule, the just one single tool exhibits a shared housing, and is fastened to a, in particular just one, robot arm of the robot. A movement of the robot arm thereby forces an identical movement of both the first and second mechanical actuating members. 
         [0010]    In a supplemental variant, the first mechanical actuating member is configured so as to preclude a radial movement by the main part of the first contact surface relative to the remaining tool and/or relative to the first rotational axis. 
         [0011]    It is best for the main part of the first contact surface to be essentially U-shaped in design, with a counter-positive geometry for positively applying a torque to a positive geometry of the tie rod. 
         [0012]    In an additional embodiment, the counter-positive geometry of the main part of the first contact surface is designed as a square for applying the torque. 
         [0013]    In a supplemental embodiment, the main part of the first contact surface of the first mechanical actuating member is designed on a partial ring with an opening for introducing the positive geometry of the tie rod, and an interior side of the partial ring forms the main part of the first contact surface. 
         [0014]    In a supplemental variant, the main part of the first contact surface of the first mechanical actuating member encompasses at least 50% or 60% of the first contact surface. A greater part of the first contact surface of the first mechanical actuating member is thus comprised of the main part of the first contact surface on the partial ring. 
         [0015]    An additional part of the first contact surface of the first mechanical actuating member is preferably moveable in design in terms of a radial movement relative to the first rotational axis and/or movable relative to the main part of the first contact surface, in particular the additional part of the first contact surface is comprised of two movable connecting pieces. The additional part of the first contact surface is thus the first contact surface minus the main part of the first contact surface of the first mechanical actuating member. However, the additional part of the first contact surface can also be formed on just a single component, for example an additional contact component, for example by designing the two connecting pieces as a single piece as an additional contact component. The additional part of the first contact surface preferably encompasses less than 50% or 40% of the entire first contact surface. The first contact surface is thus divided into the main part and additional part. 
         [0016]    In a supplemental variant, the tool encompasses at least one actuator and preferably at least one mechanism for turning the first mechanical actuating member around the first rotational axis and/or turning the second mechanical actuating member around the second rotational axis. For example, the at least one actuator is an electric motor, a pneumatically driven actuator or a hydraulically driven actuator. As a rule, the mechanism encompasses at least one gear for turning the first and/or second mechanical actuating member, i.e., for imparting a rotational movement of the first and/or second mechanical actuating member around the first and/or second rotational axis. 
         [0017]    In an additional embodiment, exclusively a rotational movement around the first rotational axis can be performed by the main part of the first contact surface and/or the partial ring, or no translational movement relative to the remaining tool can be performed by the main part of the first contact surface and/or the partial ring. 
         [0018]    In an additional embodiment, the first mechanical actuating member and second mechanical actuating member are designed coaxially to each other. The first and second mechanical actuating members are aligned coaxially to each other, i.e., have an essentially identical longitudinal axis or rotational axis. The longitudinal axis of the first mechanical actuating member is the first rotational axis, and the longitudinal axis of the second mechanical actuating member is the second rotational axis. 
         [0019]    In an additional variant, the first rotational axis and second rotational axis are essentially identical. The first and second rotational axes thus exhibit a distance of less than 5 mm, 4 mm, 3 mm, 2 mm or 1 mm, and/or the first and second rotational axes are aligned parallel to each other. 
         [0020]    In an additional embodiment, a main part of the second contact surface of the second mechanical actuating member is fixed in design in terms of a radial movement relative to the remaining tool and/or relative to the second rotational axis. The second mechanical actuating member is designed similarly to the first mechanical actuating member, and differs from the first mechanical actuating member only in that the radial distance from the second rotational axis to the second contact surface is larger than the radial distance from the first rotational axis to the first contact surface. The radial distance between two points on the first contact surface is thus larger than the radial distance between two points on the second contact surface given a similar alignment of points on the first contact surface and on the second contact surface according to the geometry of the first contact surface and the second contact surface. This is necessary because the diameter of the positive geometry of the lock nut is larger than the diameter of the positive geometry of the tie rod. 
         [0021]    In a supplemental variant, the second mechanical actuating member is designed so as to preclude a radial movement by the main part of the second contact surface relative to the remaining tool and/or relative to the second rotational axis. 
         [0022]    It is best that the main part of the second contact surface be essentially U-shaped in design, with a counter-positive geometry for positively applying a torque to a positive geometry of the lock nut. 
         [0023]    In an additional embodiment, the counter-positive geometry of the main part of the second contact surface is designed as a square for applying the torque. 
         [0024]    In a supplemental configuration, the main part of the second contact surface of the second mechanical actuating member is designed on a partial ring with an opening for introducing the positive geometry of the lock nut, and an interior side of the partial ring forms the main part of the second contact surface. 
         [0025]    In a supplemental variant, the main part of the second contact surface of the second mechanical actuating member encompasses at least 50% or 60% of the second contact surface. A greater part of the second contact surface of the second mechanical actuating member is thus comprised of the main part of the second contact surface on the partial ring. 
         [0026]    An additional part of the second contact surface of the first mechanical actuating member is preferably moveable in design relative to the main part of the second contact surface, in particular the additional part of the second contact surface is comprised of two movable connecting pieces. The additional part of the second contact surface is thus the second contact surface minus the main part of the second contact surface of the second mechanical actuating member. The additional part of the second contact surface can also be formed on just a single component, for example by designing the two connecting pieces as a single piece. 
         [0027]    In an additional embodiment, the robot encompasses a control unit for controlling the movement of the robot arm and/or for actuating the tool. 
         [0028]    In a supplemental variant, the robot encompasses an optical system with a camera for optically acquiring the position of the lock nut and/or tie rod. 
         [0029]    It is best that the additional part of the first contact surface be designed on a first component, in particular a first additional contact component, and that a rotational movement around the first rotational axis can be imparted to the first component in a closed position together with the partial ring of the first mechanical actuating mechanism. In the closed position of the first component, the additional part of the first contact surface rests on the positive geometry of the tie rod if the tie rod is located inside of the opening on the partial ring. In the open position of the component, the tie rod and/or lock nut can be moved through the opening on the housing and the opening on the partial ring. The first component consists of one or several parts. The first component can preferably be moved between the closed position and open position and vice versa by means of an actuator, and preferably a mechanism. 
         [0030]    It is best that the additional part of the second contact surface be designed on a second component, in particular a second additional contact component, and that a rotational movement around the second rotational axis can be imparted to the second component in a closed position together with the partial ring of the second mechanical actuating mechanism. In the closed position of the second component, the additional part of the second contact surface rests on the positive geometry of the lock nut if the lock nut is located inside of the opening on the partial ring. In the open position of the component, the tie rod and/or lock nut can be moved through the opening on the housing and the opening on the partial ring. The second component consists of one or several parts. The second component can preferably be moved between the closed position and open position and vice versa by means of an actuator, and preferably a mechanism. 
         [0031]    In an additional configuration, the robot encompasses a measuring system for acquiring the position of the wheels of the motor vehicle, and the control unit can be used to calculate the required rotational angle of the tie rod as a function of the acquired position of the wheels, i.e., of the steered wheels of the motor vehicle, so as to correctly set the track of the wheels. 
         [0032]    In an additional embodiment, the first and/or second mechanical actuating member is designed out of metal, in particular steel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    An exemplary embodiment of the invention will be described in more detail below with reference to the attached drawings. Shown on: 
           [0034]      FIG. 1  is a view of a tie rod with lock nut; 
           [0035]      FIG. 2  is a perspective view of a robot; 
           [0036]      FIG. 3  is a side view of a schematically depicted tool on the robot; 
           [0037]      FIG. 4  is a highly simplified cross section A-A according to  FIG. 3  through the tool; 
           [0038]      FIG. 5 a    is a perspective view of a first embodiment of a tool; and 
           [0039]      FIG. 5 b    is a perspective view of a second embodiment of a tool. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. 
         [0041]    A motor vehicle (not shown) exhibits two steered front wheels. The force necessary for steering is applied to the wheels by means of a tie rod  9 . To this end, the two tie rods  9  of the motor vehicle are joined with a steering gear (not shown) for moving the tie rods  9  in essentially the transverse direction of the motor vehicle. The tie rod  9  ( FIG. 1 ) encompasses a threaded section  16  in the area of the wheel, a neutral section  15  and a positive geometry  13  as a hexagon  14  in proximity to the steering gear (not shown). An extension of the tie rod  9  not depicted on  FIG. 1  is arranged inside of a covering hose  18 , and joined with the steering gear. The threaded section  16  of the tie rod  9  is screwed into a bearing head  17 , and the bearing head  17  exhibits a borehole with an internal thread. The threaded section  16  of the tie rod  9  is screwed into this internal thread on the borehole of the bearing head  17 . The bearing head  17  is hinged by means of a steering arm with the wheel of the motor vehicle. 
         [0042]    A robot  1  exhibits a robot arm  2 , which consists of several members  3 . The members  3  of the robot arm  2  are joined together by hinges  4 , and the individual members  3  can be moved toward each other on the hinges  4  by means of actuators  5  as the electric motors  6 . The lowermost member  3  of the robot arm  2  is fastened to a floor part  8 , and the floor part  8  rests on a floor or is secured thereto. Another end of the robot arm  2  exhibits a fastener for fastening a tool  7 , and the tool  7  is fastened to the end section of the robot arm  2  with this fastener. A control unit  35  serves to control the movement of the robot arm  2 , i.e., to control the actuators  5  and activate the tool  7 . A camera  36  on the end region of the robot arm  2  optically acquires the tie rod  9  as well as a lock nut  10  or counter nut  10 , so that the optical data acquired by the camera  6  and the optical data of the camera  36  evaluated by the control unit  35  can resultantly be used to perform a targeted movement of the tool  7  into the corresponding positions on the tie rod  9  and lock nut  10 . The outside of the lock nut  10  exhibits a positive geometry  11  as a hexagon  12  ( FIG. 1 ), so that the hexagon  12  on the lock nut  10  can be used to turn the lock nut  10 , i.e., impart a rotational movement around a first rotational axis  38  to it. This makes it possible to fix and detach the lock nut  10 . 
         [0043]    The tool  7  exhibits a housing  19 , and the housing  19  incorporates a first mechanical actuating member  20  for turning the tie rod  9 , and a second mechanical actuating member  30  for turning the lock nut  10 . The first mechanical actuating member  20  encompasses a partial ring  21  with an opening  22  and two connecting pieces  24 . An interior side of the partial ring  21  and the interior sides of the connecting pieces  24  form a first contact surface  25  for placement on the positive geometry  13  on the outside of the tie rod  9 . The geometry of the first contact surface  25  as a counter-positive geometry is here designed complementarily to the positive geometry  13  on the tie rod  9 , so that, by turning the first mechanical actuating member  20  around the first rotational axis  38  based on a positive connection between the first contact surface  25  of the first mechanical actuating member  20  and the positive geometry  13  on the tie rod  9 , a torque can thereby be applied to the tie rod  9 , as a result of which the tie rod  9  can be turned around the first rotational axis  38 , i.e., a rotational movement around the first rotational axis  38  can be imparted thereto. This makes it possible to turn the tie rod  9  and set the track of the wheel. The partial ring  21  exhibits the opening  22 , and the housing  19  further also exhibits an opening  37 . The two connecting pieces  24  can be moved with an actuator (not shown) and preferably a mechanism, and  FIG. 3  presents a closed position of the two connecting pieces  24  with dashed lines for turning the tie rod  9 . In this closed position of the connecting pieces  24 , the connecting pieces  24  also comprise an additional part  23  of the first contact surface  25 . In an open position (not shown) of the connecting pieces  24 , the additional part  23  of the first contact surface  25  cannot be used for turning the tie rod  9 , and the connecting pieces  24  are at least partially situated inside of the housing  19 . While turning the tie rod  9  with the first mechanical actuating member  20 , the connecting pieces  24  are also in the closed position, meaning that the additional part  23  of the first contact surface  25  along with the main part  26  on the partial ring  21  of the first mechanical actuating member  20  lie on the positive geometry  13  of the tie rod  9 . The first mechanical actuating member  20 , i.e., the partial ring  21  and the two connecting pieces  24 , can be turned around the first rotational axis  38  by an actuator  27  as the electric motor and a mechanism  28 . The mechanism  28  encompasses at least a gear wheel  29  for applying a torque to the first mechanical actuating member  20 . 
         [0044]    The tool  7  also encompasses a second mechanical actuating member  30  for turning the lock nut  10 . The second mechanical actuating member  30  has a structural design similar to the first mechanical actuating member  20 , i.e., exhibits a partial ring  41  and (not shown) movable connecting pieces  24 . The main part  40  of a second contact surface  31  of the second mechanical actuating member  30  is formed on the partial ring  41  of the second mechanical actuating member  30 , and the additional part (not shown) of the second contact surface  31  is provided on the inside of the connecting pieces  24  (not shown). The second mechanical actuating member  30  can be turned around a second rotational axis  39  by means of an actuator  32  and a mechanism  33  with at least one gear wheel  34 , similarly to the first mechanical actuating member  20 . The first and second mechanical actuating members  20 ,  30  only differ in terms of the diameter between the two contact surfaces  25 ,  31 . The lock nut  10  has a larger diameter on the positive geometry  11 , i.e., on the hexagon  12 , than the tie rod  9  does on the positive geometry  13 , so that the first contact surface  25  of the first mechanical actuating member  20  also exhibits a smaller diameter than the second contact surface  31  of the second mechanical actuating member  30 . 
         [0045]    In order to set the track of the wheels of the motor vehicle, the connecting pieces  24  of the first mechanical actuating member  20  are first situated in an open position (not shown) inside of the housing  19 , so that the opening  22  on the partial ring  21  of the first mechanical actuating member  20  is thereby open, and the connecting pieces (not shown) of the second mechanical actuating member  30  are simultaneously located inside of the housing  19 . As a result, the neutral section  15  of the tie rod  9  can be introduced into the opening  37  on the housing  19 , and then simultaneously introduced into the opening  22  on the partial ring  21  of the first mechanical actuating member  20  and into the opening on the partial ring  41  of the second mechanical actuating member  30  until the two rotational axis  38 ,  39  essentially correspond to the longitudinal axis of the tie rod  9  and the lock nut  10 . The connecting pieces  24  of the first mechanical actuating member  20  and the connecting pieces of the second mechanical actuating member  30  are then brought into the closed position shown with dashed lines on  FIG. 3 , after which the tool  7  is moved in the direction of the longitudinal axis of the tie rod  9  to the lock nut  10 , so that the second contact surface  31  is thereby engaged as the complementary hexagon to the hexagon  12  on the lock nut  10 . The actuator  32  is then used to impart a rotational movement around the second rotational axis  39  to the second mechanical actuating member  30 , i.e., the partial ring  41  and the two connecting pieces (not shown), thereby releasing the lock nut  10 . 
         [0046]    The robot  1  then moves the tool  7  in the direction of the longitudinal axis of the tie rod  9  and lock nut  10 , which are coaxial and identical, in the direction toward the positive geometry  13  as the hexagon  14  on the tie rod  9  until the first contact surface  25  of the first mechanical actuating member  20  is positively joined with the hexagon  14  on the tie rod  9 . The actuator  27  then imparts a rotational movement around the first rotational axis  38  to the first mechanical actuating member  20 , i.e., the partial ring  41  and two connecting pieces  24  in the closed position, until the track of the wheel has been set in a correspondingly proper manner. The rotational angle of the first mechanical actuating member  20 , and thus also the rotational angle of the tie rod  9 , is calculated by the control unit  35  as a function of the positions of the two steered wheels of the motor vehicle acquired by the measuring system (not shown). The robot  1  then similarly again moves the tool  7  in a translational movement along the longitudinal axis of the tie rod  9  back to the lock nut  10 , until the second mechanical actuating member  30  is positively joined with the positive geometry  11  on the lock nut  10 . 
         [0047]    The actuator  32  is thereupon activated, and turns the second mechanical actuating member  30  in a rotational direction opposite the rotational direction for detaching the lock nut  10 , thereby fixing the lock nut  10  in place again. The connecting pieces  24  of the first mechanical actuating member  20  and the connecting pieces of the second mechanical actuating member  30  can then be moved out of the opening  22  again and into an open position inside of the housing  19 , so that, in a side view as depicted on  FIG. 3 , the connecting pieces  24  are located inside of the housing  19 , and thereby are essentially no longer visible. As a result, the tool  7  can again be moved away from the tie rod  9  and lock nut  10  by the robot  1  by moving the tie rod  9  and lock nut  10  out of the opening  37  on the housing  19 . In the open position of the connecting pieces  24 , the tool  7  is thus designed similarly to a fork wrench, so that the tie rod  9  and lock nut  10  can be moved into this fork wrench, i.e., through the opening  37  of the housing  19 , and vice versa. 
         [0048]    Deviating from the approach described above, the tool  7  can be first be moved by the robot  1  not to the neutral section  15 , but first to the lock nut  10  for detaching the lock nut  10 , and then moved to the positive geometry  13  of the tie rod  9 , and thereupon back to the lock nut  10  again for tightening the lock nut  10 . A translational movement of the tool  7  is not necessary if the axial distance between the first and second mechanical actuating members  20 ,  30  essentially corresponds to the axial distance between the positive geometry  11  of the lock nut  10  and positive geometry  13  of the tie rod  9 . 
         [0049]    The robot  1  exhibits sensors (not shown) for acquiring the torque applied by the first and second mechanical actuating members  20 ,  30  and/or for acquiring the rotational angle position of the first and second mechanical actuating members  20 ,  30  and/or for acquiring the position of the tie rod  9  and/or lock nut  10  in the opening  37 . The robot  1  and tool  7  are additionally controlled as a function of the data provided by these sensors. For example, if the rotational angle position of the partial ring  21  is such that the latter cannot be slipped onto the hexagon  11  of the tie rod  9 , the actuator  27  is used to turn the partial ring  21  so that the hexagon  14  on the tie rod  9  is correspondingly aligned to the square on the partial ring  21  or to the hexagon of the first contact surface  25  in a closed position of the connecting pieces  24  as denoted by the dashed line on  FIG. 3 . The same also holds true analogously for the second mechanical actuating member  30 . 
         [0050]    Viewed overall, significant advantages are associated with the robot  1  according to the invention. The partial ring  21  comprising a greater part or main part  26  of the first contact surface  25  is simply formed by the interior side of the partial ring  21 , which makes it especially easy and inexpensive to manufacture. Since just one component is here involved, a greater part of the torque can thus also be applied to the lock nut  10  in an especially reliable manner. The robot  1  with the tool  7  is thus inexpensive to manufacture, and especially reliable during operation for setting the track of the wheels. 
         [0051]      FIGS. 5 a  and 5 b    show a perspective view of two embodiments of a tool  7 . As evident from the figures, each tool  7  is composed of a tool head  7   a,  into which a slotted opening  7   aa  for receiving a tie rod extends, along with a tool shaft  7   b.  The respective tool head  7   a  is flat, i.e., approximately disk-shaped, in structure. For this reason, the tool head  7   a  can be guided tightly along the bearing head  17  shown on  FIG. 1  during operation, so as to engage the locked nut  10  of the tie rod  9  via the slotted opening  7   aa.    
         [0052]    The tool  7  itself does not incorporate any active elements, such as a drive, etc., so that the tool head  7   a  and tool shaft  7   b  can be given a small design. The tool  7  is thus controlled and moved exclusively by controlling and moving the robot arm  1 , to which the tool  7  is fastened. Due to this configuration, the tool can be exchanged quickly and easily. 
         [0053]    At least one exemplary embodiment was described, wherein it must be remembered that a high number of variants thereto exists. It should also be borne in mind that the exemplary embodiment or exemplary embodiments are only examples, and hence are not intended to in any way limit the protective scope, applicability or implementability or structural design. The above description provides the expert with a suitable instruction for implementing at least one exemplary embodiment. Let it be understood that various changes can be made in the function and arrangement of the described components in an exemplary embodiment without deviating from the protective scope of the following claims and the equivalents of the following claims.