Abstract:
An apparatus for determining balancing information of an object in rotation comprises a base, an arm, a spindle, at least one force sensor, a rolling road, a controller, and an actuator. The arm is rotatably connected to the base about a pivot axis. The spindle is positioned on the arm and receives and rotates the object. The force sensor detects forces generated by the object during rotation of the object. The rolling road includes a surface upon which the object can be positioned. The controller receives force information from the sensor and calculates the balancing information from the force information. An actuator connected to both the arm and the base moves with the movement being controlled by the controller. The object can be a wheel.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to motor vehicle alignment and, more specifically, to an apparatus integrating a wheel lift and a loaded mode testing mechanism.  
         BACKGROUND OF THE INVENTION  
         [0002]    Motor vehicle alignment systems are important for ensuring that the alignments of wheels on a vehicle are within the specifications provided by motor vehicle manufacturers. If the wheels are out of alignment, there may be excessive or uneven wear. In addition, the performance of the vehicle, particularly handling and stability, may be adversely affected if the wheels are not properly aligned. As used herein, the term “wheel” or “vehicle wheel” refers to the tire and wheel assembly found on a motor vehicle. Such an assembly generally includes a conventional tire that is mounted on a metal wheel or “rim.” 
           [0003]    Many different types of apparatus have been developed to obtain balancing information for a wheel. One balancing apparatus currently in use involves mounting a wheel on a spindle. The spindle and wheel are then rotated, and forces generated by the wheel are measured to obtain such information as tire and/or rim lateral and radial runout and improper bead seating of the tire on the rim.  
           [0004]    The balancing apparatus also simulates a road test by applying a radial force or load to the wheel while the wheel is rotating. From the simulated road test, a measure of tire uniformity is obtained. Tire uniformity is the change in the sidewall and footprint as the force is exerted against the tire. In a current system, a roller having a diameter approximately one-sixth the diameter of the wheel is being used to exert the radial force against the wheel. Because the roller has such a small diameter, the force being exerted by the roller against the wheel is distributed over a considerably smaller footprint than if the force was being exerted by ground against the wheel.  
           [0005]    In the above-described balancing apparatus, the spindle is typically located greater than one wheel diameter above the surface upon which balancing apparatus is positioned. As such, a technician using the balancing apparatus is required to lift the wheel a considerable distance to mount the wheel on the spindle. This lifting and subsequent lowering of the wheel can be particularly burdensome, as certain wheels, for example for SUVs, weigh in excess of ninety pounds. There is, therefore, a need for an improved balancing apparatus that reduces the lifting required by a technician to mount the wheel on the balancing apparatus, and a balancing apparatus that better simulates road conditions during testing.  
         SUMMARY OF THE INVENTION  
         [0006]    These and other needs are met by the present invention, which in accord with one aspect is a testing system that includes a base, an arm, a spindle, at least one force sensor, and a controller. The arm is rotatably connected to the base about a pivot axis. The spindle is positioned on the arm and receives and rotates the object. The force sensor detects forces generated by the object during rotation of the object. The controller receives force information from the sensor and calculates balancing information from the force information.  
           [0007]    By providing a movable arm, the arm can be adjusted to a position that minimizes lifting of the object onto the spindle. This can reduce the stress on an operator of the apparatus caused by lifting the object onto the apparatus, particularly when the object to be spun is heavy and/or bulky. Also, the arm can be adjusted to present the object in a number of different orientations relative to the various testing equipment on the apparatus.  
           [0008]    In another aspect of the system, a rolling road is provided that includes a surface upon which the object can be positioned. This surface replicates the surface upon which the object may normally be rotated. The force sensor can also detect the force exerted upon the object by the moving surface, and the controller controls the magnitude of the force exerted upon the object by the moving surface. By using a conveyor belt as the moving surface, a contact surface of the moving surface, upon which the object contacts, is substantially planar, and this more closely replicates the actual surface upon which the object is normally rotated.  
           [0009]    In yet another aspect of the system, an actuator connected to both the arm and the base moves the arm relative to the base, and movement of the actuator is controlled by the controller. In one position of the arm, the spindle is located proximate to ground upon which the base is positioned to minimize a distance the wheel is lifted by a user to position the wheel on the spindle.  
           [0010]    In other aspects of the apparatus, the object is a wheel, and the apparatus includes a wheel debeader. The wheel debeader can be positioned on the base and can debead the wheel when the arm is in a spinning position. A wheel profiler can also be included for detecting wheel information about the wheel and transmitting the wheel information to the controller. The wheel profiler can be a vision recognition system, and the wheel information obtained by the wheel profiler includes wheel diameter, rim diameter, wheel thickness, and location of spokes on wheel.  
           [0011]    Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only an exemplary embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout, and wherein:  
         [0013]    [0013]FIG. 1 is a schematic side view of a test system in accord with an embodiment of the invention;  
         [0014]    [0014]FIG. 2 is a schematic side view of another test system;  
         [0015]    [0015]FIG. 3 is a schematic side view of the test system of FIG. 1 in one position;  
         [0016]    [0016]FIG. 4 is a schematic side view of the testing system of FIG. 1 in another position;  
         [0017]    [0017]FIG. 5 is a partial schematic side view of a rolling road; and  
         [0018]    [0018]FIG. 6 is a front view of a control panel. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    An example of a testing system, implemented in accordance with one embodiment of the invention, is illustrated in FIGS. 1 and 2. The testing system  100  includes a base  110  and a spindle  116 . The testing system  100  can also include, but is not limited to, an arm  112 , a rolling road  134 , a wheel profiler  152 , a tire inflation apparatus (not shown), and a wheel demounter  138 . Upon mounting a wheel  120  on the spindle  116 , the wheel  120  can be spun, and balancing information can be obtained regarding the wheel  120 .  
         [0020]    In certain aspects of the testing system  100 , the spindle  116  can be selectively positioned in multiple locations relative to a surface or ground  126  upon which the base  110  rests. Although the testing system  100  is not limited in the manner is which the spindle  116  is selectively positioned relative to ground  126 , in certain current aspects of the testing system  100 , the spindle  116  is mounted on the arm  112 , which is supported by the base  110 . The spindle  116  is then selectively positioned relative to ground  126  by moving the arm  112  relative to the base  110 .  
         [0021]    The testing system  100  is not limited in the manner in which the arm  112  moves relative to the base  110 . For example, the arm  112  can move translationally relative to the base  110 . However, in certain aspects of the testing system  100 , the arm  112  rotates or pivots relative to the base  110  about a pivot axis  118 , and the testing system  100  is not limited in manner in which the arm  112  rotates relative to the base  110  about the pivot axis  118 . In one aspect, however, the arm  112  and the base  110  are connected via a bearing system  130 , and the bearing system  130  allows rotation of the arm  112  relative to the base  110  about the pivot axis  118 . Any bearing system  130  so capable is acceptable for use with the testing system  100 . However, in certain aspects, the bearing system  130  is a roller bearing.  
         [0022]    Any device capable of providing the motive force to pivot the arm  112  relative to the base  110  is acceptable for use with the testing system  100 . In a current aspect, however, an actuator  114  is used to rotate the arm  112  relative to the base  110 , and any actuator  114  so capable is acceptable for use with the testing system  100 . For example, the actuator  114  can be a gearing system connected to the bearing system  130  that rotates the arm  112  relative to the base  110 . In certain current aspects, however, the actuator  114  rotates the arm  112  relative to the base  110  by either extending or retracting in a piston-like manner. Although, as illustrated, the actuator  114  is connected to both the base  110  and the arm  112 , the testing system  100  is not limited in this manner. For example, the actuator  114  can be connected to the arm  112  and also to the surface or ground  126 .  
         [0023]    The testing system  100  can also include a device, such as a controller  142 , to manage the operation of the testing system  100 . For example, the device or controller  142  can control the movement of the arm  112  and the spindle  116  relative to ground  126 . The controller  142  can also include a database containing various information related to wheel balancing, for example tire size, tire speed rating, inflation pressure, vehicle corner weight, and past data for a given type of vehicle and/or type of wheel. It should be noted, however, that the testing system  100  is not limited as to a particular type of controller  142 , and the controller  142  is also not limited as to the particular functions described above.  
         [0024]    The controller  142  can also include input/output devices, which allow a technician or operator of the testing system  100  to interface with the controller  142  so as to operate the testing system  100 . The controller  142  and input/output devices can be physically integrated with the testing system  100 . Alternatively, the controller and/or input/output devices can be connected to, but physically separate from, the testing system  100 . In certain current aspects of the testing system, as illustrated in FIG. 2, the controller  142  and input/output devices are incorporated into the testing system  100  as a control panel  142  and a monitor  140 . Although not necessary, both the controller  142  and monitor  140  can be respectively mounted on adjustable stands  146 ,  144 . The controller  142  is discussed in more detail below.  
         [0025]    The controller  142  can be connected to a positioning monitoring device, such as an encoder (not shown), to determine the location of the spindle  116  or arm  112  relative to ground  126 . In this manner, the controller  142  can monitor and control the movement and location of the spindle  116  and arm  112  relative to ground  126 .  
         [0026]    As illustrated in FIGS. 3 and 4, the testing system  100  is capable of selectively positioning the spindle  116  relative to the ground  126  in multiple positions. Although the testing system  100  is not limited in the manner is which the spindle  116  is positioned relative to ground  126 , in certain aspects of the testing system  100 , the spindle  116  is positioned relative to ground  126  by moving the arm  112 , upon which the spindle  116  is mounted, relative to the base  110 .  
         [0027]    In one position, as illustrated in FIG. 3, the spindle  116  can be located proximate to ground  126  so as to minimize a distance the wheel  120  is raised from ground to be positioned on the spindle  116 . By positioning the center of the spindle  116  away from ground  126  at a distance of approximately the radius of the wheel  120 , a distance the wheel  120  is lifted by a technician to position the wheel  120  on the spindle  116  is minimized or eliminated. Although the distance between the center of the spindle  116  and the ground  126  varies depending upon the size of the wheel  120 , in certain aspects of the testing system  100 , the distance is less than twenty-four inches. This same position can also be used when the wheel  120  is removed from the spindle  116 .  
         [0028]    In another position, as illustrated in FIG. 4, the spindle  116  can be raised relative to ground  126  to position the wheel  120  for rotation. The spindle  116  can also be located relative to the ground  126  in other positions. For example, the spindle  116  can be moved to other positions when the wheel  120  is being tested using a rolling road  134  or when using a wheel demounter  138 .  
         [0029]    As illustrated in FIGS. 2 and 5, the testing system  100  can also include a rolling road  134 . The rolling road  134  provides a surface against which the outer circumference of wheel  120  contacts during rotation of the wheel  120 . In one aspect, the rolling road  134  exerts a predetermined force on the wheel  120  when the wheel  120  is rotating, and any rolling road  134  so capable is acceptable for use with the testing system  100 . The force against the wheel  120  can simulate forces that the wheel  120  would experience during a road test when the wheel  120  is mounted on a vehicle.  
         [0030]    In certain aspects of the testing system  100 , the surface of the rolling road  134  is a conveyor belt  136 , which is supported, for example, by a plurality of rollers  152 . The conveyor belt  136  presents a surface that is substantially planar and more accurately replicates the road surface contact area or footprint that the wheel  120  would encounter during actual use of the wheel  120  on a vehicle. In contrast, previous devices for exerting force against a wheel, such as a single roller, provide a much smaller contact area. As such, by using a conveyor belt  136  to exert the predetermined force against the wheel  120 , the manner in which the wheel  120  deforms more closely replicates the deformation of the wheel  120  during actual use than if the wheel  120  is deformed by a single roller.  
         [0031]    Although shown connected to the base  110 , the rolling road  134  is not limited in this manner. For example, the rolling road  134  can be positioned directly on the ground  126 . Also, in one of the positions of the spindle  116  relative to ground  126 , the spindle  116  can present the wheel  120  to the rolling road  134  for testing of the wheel  120 .  
         [0032]    Although any device capable of measuring the force exerted by the rolling road  134  against the wheel  120 , in certain current aspects of the testing system  100 , a force sensor  132  is positioned on the actuator  114  and is used to inferentially measure the force being exerted against the wheel  120  by the rolling road  134 . The force sensor  132  can also be connected to the controller  142  to allow the controller  142  to actively adjust the position of the spindle  116  relative to the rolling road  134  such that a specific desired force can be exerted against the wheel  120  by the rolling road  134 .  
         [0033]    In certain modes of operation, the testing system  100  is used to test the wheel  120  and provide, if necessary, information useful in balancing the wheel  120 . The rotation of the unbalanced wheel  120  in the spindle  116  creates a vibration, which can be measured to determine the degree of unbalance of the wheel  120 .  
         [0034]    The wheel  120  is connected to the arm  112  and spun. Many devices capable of receiving the wheel  120  and spinning the wheel  120  are commonly known, and the invention is not limited as to a particular device for receiving and spinning the wheel  120 . In one aspect of the testing system  100 , however, a spindle  116  receives the wheel  120 .  
         [0035]    During testing, when the wheel  120  is spinning, balancing measurements, such as dynamic and static imbalance, can be obtained about the wheel  120 . As such, the testing system  100  can also include a device for obtaining balancing measurements, and any device capable of obtaining balancing measurements is acceptable for use with the testing system  100 . Many types of devices capable of obtaining balancing measurements are known by those skilled in the art, and the testing system  100  is not limited as to a particular device for obtaining balancing measurements. An example of a device for obtaining balancing measurements is a VPI System 3 Wheel Balancer manufactured by John Bean of Conway Ark.  
         [0036]    When the wheel  120  is spinning, measurements regarding the roundness of the wheel  120  can also be obtained. The testing system  100  is not limited as to the manner in which the roundness of the wheel  120  can be determined. However, in certain current aspects, the testing system  100  includes a first force sensor  132  that measures forces on the arm  112 . The spinning of an out-of-round wheel  120  will exert forces on the arm  112 , and these forces can be measured by the first force sensor  132 . Although not limited in this manner, the first force sensor  132  can be located on the actuator  114  or on the base  110 .  
         [0037]    To prevent the vibration from destabilizing the testing system  100 , the base  110  is fixed to a surface or ground  126 , and any base  110  so capable is acceptable for use with the testing system  100 . In one aspect, however, the base  110  includes a bottom plate  122  fixed to the surface  126  extending from the bottom plate  122 . The testing system  100  is not limited in the manner in which the bottom plate  122  is fixed to the surface bottom plate  122 . However, in one aspect, the bottom plate  122  is fixed to the surface using anchor bolts (not shown) through anchor holes in the bottom plate  122 .  
         [0038]    The testing system  100  can also include a wheel demounter  138 , also known as a tire debeader. A tire is typically sealed to the rim by a bead, which is generally wire reinforced and resists deformation. For this purpose, the bead has a diameter that is somewhat less than the diameter of the wheel rim flange and is positioned between the spaced flanges of the wheel rim. To break the seal between the tire and rim, the beads are unsealed or “broken” by moving the beads axially inward. The tire can then be repositioned on the rim or removed entire from the rim. As is known to those skilled in the art, many types of wheel demounters  138  are capable of loosening or removing the tire from its rim, and the testing system  100  is not limited as to a particular type of wheel demounter  138 . Although not limited in this manner, the wheel demounter  138  is attached to the base  110  of the testing system  100 , for example, with a mount  150  that allows movement of the wheel demounter  138  relative to the base  110 .  
         [0039]    One advantage of including a wheel demounter  138  with the testing system  100  is that the wheel demounter  138  allows a user of the testing system  100  to adjust the tire on the rim without removing the wheel  120  from the testing system  100 . In so doing, for example, the user can properly locate and adjust low and high points of the tire and rim without having to remove and remount the wheel  120  on the testing system  100 .  
         [0040]    Upon obtaining the balancing measurements, a process, sometimes known as optimization, can be used to enable a technician to properly locate the tire on the rim. After obtaining the optimized tire to rim position, both the tire and rim are marked prior to adjusting the tire on the rim. Although any method of marking the tire and rim is acceptable for use with the testing system  100 , in a current aspect, the wheel  120  and rim are each marked with a laser (not shown), which can be positioned on or off the testing system  100 . Once marked, the tire can be adjusted on the rim using the wheel demounter  138  such that the tire and rim are in an optimized position relative to each other. The tire can then be reinflated and subjected to additional testing, such as spinning for final balancing.  
         [0041]    The testing system  100  can also use a wheel profiler  152 . As known by those skilled in the art, a wheel profiler  152  is a vision recognition system that visually obtains tire information, such as tire diameter, thickness of the tire, and where the tire is located relative to the rim. This information can then be automated provided to the controller  142 . The wheel profiler  152  can be positioned adjacent to the testing system  100 , or as illustrated in FIG. 2, the wheel profiler  152  can be attached to the base  110 .  
         [0042]    An illustrative example of the controller  142  is shown in FIG. 6. It should be understood, however, that the controller  142  is not limited to the particular layout illustrated or the features shown on the controller  142 . The controller  142  includes up and down arrows  160 ,  162  for positioning the spindle  116  up and down. Start and stop buttons  164 ,  168  are included for starting and stopping the spinning of the spindle  116  and wheel  120 . A help button  166  is including for providing help information to an operator of the testing system  100 . The controller  142  also includes two meters  174 ,  176 , which are respectively used for the inside and outside of the wheel  120 . Each indicator  174 ,  176  includes a direction needle  178 ,  180 , a top dead center (TDC) indicator  174 ,  176 , and a weight indicator  182 ,  184 . After the wheel  120  is spun and the balancing information calculated, the two meters  174 ,  176  indicate the locations on the inside and outside of the wheel  120  where weights are to be placed to balance the wheel  120 .  
         [0043]    The present invention can be practiced by employing conventional materials, methodology and equipment. Accordingly, the details of such materials, equipment and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., in order to provide a thorough understanding of the present invention. However, it should be recognized that the present invention can be practiced without resorting to the details specifically set forth. In other instances, well known processing structures have not been described in detail, in order not to unnecessarily obscure the present invention.  
         [0044]    Only an exemplary aspect of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.