Abstract:
An apparatus includes a backing surface that is operable to support a workpiece, and a mounting structure that is operable to move linearly between a first position and a second position. Movement from the first position to the second position is in a direction toward the backing surface. A first engaging part is fixedly connected to the mounting structure for movement in unison with the mounting structure, wherein the first engaging part is operable to engage a first portion of the workpiece. A second engaging part is rotatably connected to the mounting structure such that the second engaging part rotates with respect to the first engaging part in response to movement of the mounting structure from the first position to the second position, wherein the first engaging part is operable to engage a second portion of the workpiece.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. Non-Provisional patent application Ser. No. 14/313,343, filed on Jun. 24, 2014, which is a continuation of U.S. Non-Provisional patent application Ser. No. 13/309,695, filed on Dec. 2, 2011, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/418,939, filed on Dec. 2, 2010. 
     
    
     BACKGROUND 
       [0002]    Sheet metal bending apparatuses are well-known. Typically, sheet metal bending dies operate by supporting a workpiece between two relatively moveable die portions. For example, the workpiece may be held in a fixed position with respect to a non-moving backing portion of the die, while an anvil portion of the die is moved into contact with the workpiece to bend a portion of the workpiece about a bend line. 
         [0003]    While such bending operations are trivial when applied to a planar workpiece, the complexity of the operation is increased substantially when the workpiece has a profiled shape prior to the bending operation. In such a case, the bend line itself is profiled, and the bend must be made in consideration of the profile of the bend line. One typical approach to bending a workpiece at a profiled bend line involves providing two or more anvil portions that are relatively moveable to a fixed backing portion of the die. These anvil portions are typically configured such that each moves along its own line of action, substantially perpendicular to the profile of the workpiece. When the two or more anvil portions first contact the workpiece during the course of the bending operation, there will typically be a gap between the two anvil portions at the location where the anvil portions contact the workpiece. This can cause some inconsistencies or quality issues in the finished workpiece. Furthermore, when the profile includes a radiused shape, the line of action of the anvil portion responsible for bending the part within the radius necessarily does not move normal to the entirety of the radiused portion. 
       SUMMARY 
       [0004]    One aspect of the disclosed embodiments is an apparatus that includes a backing surface that is operable to support a workpiece, and a mounting structure that is operable to move linearly between a first position and a second position. Movement from the first position to the second position is in a direction toward the backing surface. A first engaging part is fixedly connected to the mounting structure for movement in unison with the mounting structure, wherein the first engaging part is operable to engage a first portion of the workpiece during linear motion of the mounting structure from the first position to the second position. A second engaging part is rotatably connected to the mounting structure such that a rotational axis of the second engaging part moves in unison with the mounting structure and the second engaging part rotates with respect to the first engaging part in response to movement of the mounting structure from the first position to the second position, wherein the first engaging part is operable to engage a second portion of the workpiece during linear motion of the mounting structure from the first position to the second position. 
         [0005]    Another aspect of the disclosed embodiments is an apparatus that includes a body, a first engaging part defined on the body, a cam unit that is rotatably mounted to the body for rotation between a first position and a second position, and a second engaging part defined on the cam unit. The first engaging part and the second engaging part are positioned adjacent to each other when the cam unit is in the first position. The apparatus also includes a backing structure having a top surface for supporting at least a portion of a workpiece and a side surface such that an overhanging portion of the workpiece extends off of the top surface adjacent to the side surface and is not supported by the top surface The body is movable linearly from a first position to the second position while the cam unit rotates with respect to the body such that the first engaging part moves linearly, the second engaging part moves linearly and rotationally, and the first engaging part and the second engaging part each engage the overhanging portion of the workpiece. 
         [0006]    Another aspect of the disclosed embodiments is a method that includes placing a workpiece on a top surface of a backing structure having a top surface and a side surface such that an overhanging portion of the workpiece extends off of the top surface and is not supported by the top surface. The method also includes supporting a body on a mounting structure that is operable to move linearly from a first position to a second position, wherein a first engaging part is defined on the body. The method also includes mounting a cam unit to the body for rotation with respect to the body between a first rotational position and a second rotational position, wherein a second engaging part is defined on the cam unit. The method also includes moving the mounting structure from the first position to the second position while causing rotation of the cam unit such that the first engaging part moves linearly, the second engaging part moves linearly and rotationally, and the first engaging part and the second engaging part each engage the overhanging portion of the workpiece. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The description herein makes reference to the accompanying drawings, wherein like-referenced numerals refer to like parts throughout the several views, and wherein: 
           [0008]      FIG. 1  is a perspective view showing an example of a workpiece having a profiled bend line; 
           [0009]      FIG. 2  is a side view of the workpiece of  FIG. 1 ; 
           [0010]      FIG. 3  is a right side perspective view showing a bending die; 
           [0011]      FIG. 4  is a left side perspective view showing the bending die; 
           [0012]      FIG. 5  is an exploded view showing an anvil of the bending die; 
           [0013]      FIG. 6  is a right side view showing the bending die; 
           [0014]      FIG. 7  is a left side view showing the bending die; 
           [0015]      FIG. 8  is a perspective view showing a cam unit of the bending die; 
           [0016]      FIG. 9  is a cross-section view showing a driver of the bending die; 
           [0017]      FIG. 10A  is a front view showing the bending die positioned with respect to the workpiece prior to a bending operation; 
           [0018]      FIG. 10B  is a side view showing the bending die positioned with respect to the workpiece prior to the bending operation; 
           [0019]      FIG. 11A  is a front view showing the bending die positioned with respect to the workpiece subsequent to the bending operation; and 
           [0020]      FIG. 11B  is a side view showing the position of the bending die relative to the workpiece subsequent to the bending operation. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]      FIGS. 1-2  show an example of a workpiece  10  that can be produced using a bending die  100  ( FIGS. 3 ,  4 ,  6  and  7 ). The workpiece  10  can be a thin-walled part that is fabricated from sheet metal. The workpiece  10  includes a body portion  12  and a flange portion  14 . The body portion  12  has a profiled shape including a first portion  16 , a second portion  18 , and a radiused portion  20 . The first portion  16  and the second portion  18  are each substantially planar but extend at an angle with respect to one another. The radiused portion  20  interconnects the first portion  16  and the second portion  18  by providing a radiused profile between the first and second portions  16 ,  18 . 
         [0022]    The body portion  12  and the flange portion  14  meet at a profiled bend line  22 . The profiled bend line  22  extends continuously along the body portion  12 , including along the first portion  16 , the radiused portion  20 , and the second portion  18 . The flange  14  includes a first portion  24  that is adjacent to the first portion  16  of the body portion  12  and a second portion  26  that is adjacent to the second portion  18  of the body portion  12 . The first and second portions  24 ,  26  of the flange  14  are disposed on the same side of the profiled bend line  22 . The first and second portions  24 ,  26  of the flange  14  meet at a notch  28  that may be provided adjacent to the radiused portion  20  of the body portion  12  in order to facilitate a bending operation by which the flange  14  is formed. Prior to the bending operation, the first and second portions  16 ,  18  of the body portion  12  are substantially coplanar with the first and second portions  24 ,  26  of the flange  14 . 
         [0023]    A bend is defined at the profiled bend line  22  by a bending operation. The bend that is defined at the profiled bend line  22  by the bending operation can be of any desired geometry. For example, a 90° bend can be defined at the profiled bend line  22  by the bending operation. 
         [0024]    The workpiece  10  is shown and described herein to allow for understanding of the disclosure. The particular geometry of the workpiece  10  is not critical, and the bending die  100  ( FIGS. 3 ,  4 ,  6  and  7 ) can be utilized to form workpieces having other geometries. It is specifically contemplated that the bending die  100  can be utilized to form flange portions along profiled bend lines on workpieces having geometries other than those shown with respect to the workpiece  10 . 
         [0025]    The bending die  100 , as shown in  FIGS. 3-4 , is configured to form the flange  14  of the workpiece  10  ( FIGS. 1-2 ). It should be appreciated that the geometry of the bending die  100  in the illustrated example corresponds to the workpiece  10 . However, other geometries can be provided for the bending die  100  to accommodate differently configured workpieces. In particular, the bending die  100  can be configured to form flange portions of any selected geometry along radiused bend lines of any selected geometry. 
         [0026]    The bending die  100  includes an anvil  102  and a driver  104 . At least one of the anvil  102  or the driver  104  is mounted for movement, such as on a press or an actuator. During the bending operation, the anvil  102  and the driver  104  move relative to one another. The bend is formed at the profiled bend line  22  as a result of this relative motion. 
         [0027]    In one example, the anvil  102  is mounted for movement with respect to the driver  104 . The anvil  102  can be supported by a linear actuator (not shown in  FIGS. 3-4 ), such as a hydraulic press, that moves the anvil  102  along a single line of action in a single direction into and out of engagement with the driver  104 . In this example, the driver  104  can be disposed in a fixed position, such that the driver  104  as a whole does not move in response to engagement of the anvil  102  with the driver  104 . 
         [0028]    In another example, the anvil  102  can be disposed in a fixed position such that it does not move as a whole. In this example, the driver  104  can be supported by a linear actuator (not shown in  FIGS. 3-4 ), such as a hydraulic press, that moves the driver  104  along a single line of action in a single direction into and out of engagement with the anvil  102 . 
         [0029]    In both examples, the driver  104  can engage the anvil  102  in order to actuate rotational movement of a cam unit  106  that is rotatably supported by the anvil  102 . In particular, rotational movement of the cam unit  106  can be actuated by engagement of at least a portion of the driver  104  with the cam unit  106 . 
         [0030]    In the illustrated example, the anvil  102  moves vertically. It should be understood, however, that any orientation could be utilized. In particular, the bending die  100  can be configured such that at least one of the anvil  102  or the driver  104  is mounted for movement in any direction, such as horizontally, vertically, or at any desired angle. 
         [0031]    As best seen in  FIG. 5 , the anvil  102  can include a body portion  108 , a cover portion  110 , and the cam unit  106 . The anvil  102  can further include a mounting portion  111  for connecting the anvil  102  to a press or actuator. In the illustrated example, the cam unit  106  is mounted between the body portion  108  and the cover portion  110 . More particularly, the cam unit  106  is disposed within an internal cavity  112  that is defined by the body portion  108  of the anvil  102 . The internal cavity  112  faces the cover portion  110 , such that the cam unit  106  may be installed within the internal cavity  112  of the body portion  108  and retained therein by subsequent assembly of the cover portion  110  with respect to the body portion  108 , such that the cam unit  106  is disposed between the body portion  108  and the cover portion  110 . As a result, the cam unit  106  is rotatably mounted to the body portion  108  for rotation at least between a first position and a second position. Other configurations can be utilized to mount the cam unit  106  for rotation with respect to the body portion  108 . 
         [0032]    The cam unit  106  is mounted for rotation with respect to at least part of the anvil  102 , such as the body portion  108  and the cover portion  110  thereof. The cam unit  106  can be moveable between the first, or disengaged position, and the second, or engaged position, which will be explained in detail herein. The disengaged and engaged positions can define rotational limits of travel for the cam unit  106 . 
         [0033]    Opposite the cover portion  110  of the anvil  102 , a cutout  114  can be formed in the body portion  108  to allow a portion of the cam unit  106  to extend laterally out of the internal cavity  112 , as best seen in  FIG. 6 . Also, the internal cavity  112  is open in an area facing the driver  104 , such that a portion of the cam unit  106  extends out of the internal cavity  112  for engagement with the driver  104 . 
         [0034]    To retain the cam unit  106  within the internal cavity  112 , however, a periphery of the internal cavity  112  can extend through an arc that is greater than 180°, such that interference between the body portion  108  and the cam unit  106  retains the cam unit  106  within the internal cavity  112 . This configuration eliminates the need for an axle or other structure that supports the cam unit  106  with respect to the body portion  108  and the cover portion  110 . However, an axle or other supporting structure (not shown) could be provided in order to retain and rotatably support the cam unit  106  with respect to the body portion  108  and the cover portion  110  of the anvil  102 . In such a configuration, an interference fit is not needed to retain the cam unit  106  with respect to the body portion  108 . 
         [0035]    A biasing element  118  can be operably connected to the cam unit  106  in order to bias the cam unit  106  toward its disengaged position, as best seen in  FIG. 7 . In one example, the cover portion  110  can include an opening  116  that extends laterally through the cover portion  110  at a spaced location with respect to an outer periphery of the cover portion  110 . The opening  116  provides an area in which the biasing element  118  may be installed. A first portion of the biasing element  118  is disposed in a fixed position with respect to the anvil  102 , such as by connection to or engagement with one of the body portion  108  or the cover portion  110  of the anvil  102 . A second portion of the biasing element  118  is connected to the cam unit  106 , such as by a connector  119   a  and a pin  119   b.  In the illustrated example, the biasing element  118  is a pneumatic cylinder that resists retraction of a piston rod into the cylinder in order to exert a biasing force. Other structures can be used as the biasing element  118 , such as a wire spring, an elastic material, or other structures that are able to exert a biasing force, whether in tension, compression, torsion, or otherwise. 
         [0036]    Opposite the internal cavity  112 , a first bending surface  124  is defined on the body portion  108  of the anvil  102 . The first bending surface  124  can be substantially planar and is engageable with the workpiece  10  during the bending operation. The first bending surface  124  can be defined at an edge or corner of the body portion  108  of the anvil  102 . In one example, the first bending surface  124  is defined at an edge where an outer surface  125   a  of the body portion  108  meets a lower surface  125   b  of the body portion  108 . The first bending surface  124  can be radiused in order to facilitate bending of workpieces without tearing. 
         [0037]    As shown in  FIG. 8 , the cam unit  106  can include a supporting portion  128  and a cam portion  130 . The supporting portion  128  is adapted to be received within the internal cavity  112  of the body portion  108 . The supporting portion  128  has an arcuate peripheral surface  132  having a substantially circular shape. In the illustrated example, the arcuate peripheral surface  132  does not, however, define a complete circle. Rather, the arcuate peripheral surface  132  extends along an arc of approximately 270°, from a first surface, namely an engagement surface  134  that is formed on the supporting portion  128  of the cam unit  106  for engagement with the driver  104 , to a second surface  137  that is formed on the supporting portion  128  of the cam unit  106  adjacent to a second bending surface  136  that is defined on the cam portion  130 . The second bending surface  136  is utilized to form a portion of the flange  14  of the workpiece  10 , such as the second portion  26  of the flange  14 . 
         [0038]    The cam portion  130  of the cam unit  106  can extend laterally outward from the supporting portion  128  of the cam unit  106 . The cam portion  130  and the supporting portion  128  may be formed as separate pieces that are formed together, such as by fasteners  138 , or may be formed as a unitary structure. 
         [0039]    The cam portion  130  is configured to be received within the cutout  114  and the body portion  108  of the anvil  102  for rotation with respect to the body portion  108  of the anvil  102 . In this regard, a first limit surface  140  can be provided on the cam portion  130  for engagement with a second limit surface  142  that is defined on the body portion  108  on the periphery of the cutout  114 . Engagement of the first limit surface  140  with the second limit surface  142  sets a limit of travel for the cam unit  106  with respect to the body portion  108  and defines the disengaged position of the cam unit  106 . The biasing element  118  biases the cam unit  106  toward this limit of travel, such that the first limit surface  140  is brought into engagement with the second limit surface  142  by the biasing element  118  absent application of an external force that overcomes the biasing force that is applied by the biasing element  118 . Other features could alternatively be provided to define a limit of radial travel for the cam unit  106 . 
         [0040]    In order to rotate the cam unit  106  from the disengaged position to the engaged position during the bending operation, the driver  104  includes an engagement member  144 , as shown in  FIG. 9 . The engagement member  144  can include a substantially planar surface  145  that is adapted to engage the engagement surface  134  of the cam unit  106 . The engagement member  144  also includes an arcuate peripheral surface  146 . Other configurations can be provided for the engagement member  144 , such as a roller. 
         [0041]    The engagement member  144  can be supported by a carriage  147 . The carriage  147  includes an arcuate recess  148  in which the engagement member  144  is received. The arcuate recess  148  is shaped complementary to the arcuate peripheral surface  146  of the engagement member  144 . This allows the engagement member  144  to pivot with respect to the carriage  147 . Thus, when the substantially planar surface  145  of the engagement member  144  contacts the engagement surface  134  of the cam unit  106 , the engagement member  144  can pivot such that the substantially planar surface  145  maintains a coplanar relationship with respect to the engagement surface  134  of the cam unit  106 . In particular, the engagement member  144 , as supported by the carriage  147 , pivots about an axis that is substantially aligned with an axis of rotation of the cam unit  106 . 
         [0042]    To allow adjustment of the position of the engagement member  144 , the carriage  147  can be disposed on an inclined surface  150  of a sliding mount  152  of the driver  104 . The sliding mount  152  allows the longitudinal position of the engagement member  144  and the carriage  147  to be adjusted with respect to the anvil  102 , while the sliding mount  152  and a base  154  on which the sliding mount  152  is disposed remain in a fixed position with respect to the anvil  102 . In one example, the longitudinal adjustment is performed by rotating a threaded fastener  151  that is disposed within a bore  153  that is formed through the sliding mount  152  adjacent to the inclined surface  150 . The threaded fastener  151  is threadedly connected to a threaded bore  149  that is formed in the carriage  147 . By rotation of the threaded fastener  151 , the threaded connection between the threaded fastener  151  and the threaded bore  149  is advanced or retracted, thereby advancing or retracting the carriage  147  along the inclined surface  150 . During such an adjustment, the engagement member  144  travels along the inclined surface  150  of the sliding mount  152  that is raised or lowered as it is moved in the longitudinal direction with respect to the base. The result of advancing or retracting the position of the engagement member  144  with respect to the anvil  102  is that the distance between engagement member  144  and an axis of rotation of the cam unit  106  is changed. This changes the degree of rotation of the cam unit  106  in response to being driven by engagement with the engagement member  144  through a linear stroke of a given length. 
         [0043]    In use, the workpiece  10  can be supported on a backing die  160 , as shown in  FIGS. 10A-10B . The backing die  160  holds the workpiece  10  in a fixed position and has a geometric configuration similar to that of the workpiece  10  in its final form after the bending operation. The backing die  160  and the driver  104  can be both fixed to a base surface  162  or other immovable object or objects, such that the backing die  160  and the driver  104  are disposed in a fixed position with respect to one another. The anvil  102  can be supported for upward and downward movement, such as on a linear actuator  164 . Alternatively, the anvil  102  can be fixed, and the backing die  160  and the driver  104  can be mounted for movement. An engagement structure, such as an upper holder  161 , can be positioned opposite the backing die  160  to maintain the workpiece  10  in secure engagement with the backing die  160 . The upper holder  161  can be mounted to the linear actuator  164 , an upper die (not shown) or other structure, and may be mounted thereto by resilient means such as a spring. 
         [0044]    Initially, with the body portion  12  of the workpiece  10  supported by the backing die  160 , the area of the workpiece  10  that will become the flange  14  is not supported by the backing die  160 , and the profiled bend line  22  is disposed within a bend plane  166  that lies between the backing die  160  and the anvil  102 . At this point, the area of the workpiece  10  that will become the flange  14  is positioned adjacent to the first bending surface  124  and the second bending surface  136  and may be spaced therefrom by a distance sufficient to allow the workpiece  10  to be positioned on the backing die  160  without interference with the bending die  100 . 
         [0045]    Prior to the bending operation, the anvil  102 , including the first and second bending surfaces  124 ,  136  on the body portion  108  and the cam unit  106 , is disposed on a first side of the workpiece  10 . The backing die  160  is disposed opposite the anvil  102  on a second side of the workpiece  10 . The driver  104  can also be disposed on the second side of the workpiece  10 . 
         [0046]    Just prior to the bending operation, the bending die  100  is either spaced from the driver  104  or positioned with respect to the driver  104  such that, regardless of contact between the two elements, the cam unit  106  has not been rotated. Thus, the cam unit  106  is in its disengaged position, wherein the first limit surface  140  on the cam unit  106  is in engagement with the second limit surface  142  on the body portion  108  of the anvil  102  under influence of the biasing element  118 . At this point, the first bending surface  124  and the second bending surface  136  are positioned with respect to one another such that a continuous bending surface is defined by the first bending surface  124  and the second bending surface  136 . This continuous surface that is defined by both the first bending surface  124  and the second bending surface  136  is complementary in shape to the profiled shape of the body portion  12  of the workpiece  10  at the profiled bend line  22 . Thus, upon initial contact of the first bending surface  124  and the second bending surface  136  with the workpiece  10 , there will be no substantial gaps between the first bending surface  124  and the second bending surface  136 . 
         [0047]    The bending operation proceeds by moving the anvil  102  of the bending die  100  toward the driver  104  using the linear actuator  164 , as shown in  FIGS. 10A-10B . As the anvil  102  moves toward the driver  104 , the first bending surface  124  and the second bending surface  136  come into engagement with the workpiece  10 . Thus, the area of the workpiece  10  that is in engagement with the first bending surface  124  and the second bending surface  136  will begin to bend. 
         [0048]    During this motion of the anvil  102  toward the driver  104 , the engagement surface  134  of the cam unit  106  comes into engagement with the engagement member  144  of the driver  104 . This causes rotation of the cam unit  106 , since the resulting rotational force imposed upon the cam unit  106  is greater than the biasing force applied by the biasing element  118 . Engagement of the first bending surface  124  with the workpiece  10  bends the first portion  24  of the flange  14 . Engagement of the second bending surface  136  with the workpiece  10  bends the second portion  26  of the flange  14 . Thus, the linear motion of the first bending surface  124  of the anvil  102  forms the first portion  24  of the flange  14 , while the rotational movement of the second bending surface  136  forms the second portion  26  of the flange  14 . In this regard, it should be noted that the size and extents of the cam unit  106  and the second bending surface  136  are selected such that the second bending surface  136  on the cam unit  106  extends throughout the entirety of the radiused portion  20  of the body portion  12  of the workpiece  10 , thus improving the quality of the bend that is applied in the area of the radiused portion  20 . 
         [0049]    While the invention has been described in connection with certain embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.