Abstract:
An incremental forming machine binder is provided that has a blank holding opening that may be subdivided into smaller blank holding openings. The opening is subdivided by one or more clamping modules that are connected by connecting modules to each other and the frame. Clamps are attached to the clamping modules to clamp blanks in the blank holding openings. Multiple blanks may be secured to the binder for incremental forming.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a fixture assembly for an incremental forming machine and a method for configuring the fixture assembly. 
       BACKGROUND 
       [0002]    One process for forming a sheet metal prototype part, manufacturing low volumes of sheet metal components, or custom sheet metal parts is to build a low production die set for a stamping machine. This process is time consuming and expensive. The die set needs to be built and is limited to forming a specific part. 
         [0003]    Incremental forming is a process used for forming sheet metal prototypes, manufacturing low volumes of sheet metal components, or custom sheet metal. An incremental forming machine can be used to form a prototype part by using one or more stylus tools that follow CAD data to form the sheet metal in increments into a prototype part. Incremental forming offers the advantages of low cost, reduced time between design freeze and delivery of prototype parts, and reduced energy consumption. One problem with incremental forming is that even for a small part the blank used must fill the entire binder. This may create excessive scrap and also affect part dimensional accuracy or to sacrifice cycle time to achieve tight dimensional accuracy when making small prototypes. Incremental forming productivity is reduced because the stylus tools can only form one prototype part per fixture set-up. A new blank must be loaded in the binder of the incremental forming machine to make each additional part. 
         [0004]    This disclosure is directed to the above problems and other problems as summarized below. 
       SUMMARY 
       [0005]    According to one aspect of the disclosure, an incremental forming machine is provided that has a binder opening that can be divided into smaller portions to allow a smaller blank to be formed. This reduces the amount of scrap produced by the incremental forming process. Clamp supporting segments are used to support clamps that secure multiple blanks in the binder. This eliminates the need to reload the binder with a new blank after forming each part. Multiple parts can be formed in separate areas on a single blank by simply entering CAD data for each of the parts. The present invention allows for different sized parts or multiple parts to be formed on different sized blanks in a single fixture set-up. 
         [0006]    In one embodiment, a fixture assembly is provided for forming one or more smaller blanks The fixture assembly includes a frame that defines an opening and dividing members that extend across the opening. The dividing members include a plurality of clamp support segments and connecting members. The clamp support segments support a clamping mechanism to secure the smaller blanks in the larger opening. The clamp support segments are interconnected in the opening by the connecting members to provide a clamping mechanism about the blank periphery. The clamping mechanism can be manually, pneumatically, hydraulically, or electrically actuated. For structural support, a reinforcement rod is inserted through the clamp support segments and the connecting members. The reinforcement rods are fastened to the frame to ensure that the clamp support segments rigidly support the clamping mechanism during the forming process. 
         [0007]    In another embodiment, a method is provided for configuring the fixture assembly. The fixture assembly is configured by framing an opening for a blank. The framed opening is divided into a plurality of sub-frames by assembling within the frame a plurality of clamp support segments, connecting members, and reinforcement rods. The clamp support segments may be mechanically connected to the frame and one or more clamp support segments by the connecting members. This allows for all sides of the blank to be secured during the forming process. The clamp support segments and the connecting members are reinforced by the reinforcement rods. The reinforcement rods support the clamp support segments and the connecting members to resist the forces applied by the stylus tools of the incremental forming machine on the blank. The reinforcement rods rigidly reinforce the clamp support segments and the connecting members. This method saves time and improves the efficiency of the incremental forming process by allowing blanks of various sizes to be formed without unloading and reloading the incremental forming machine. 
         [0008]    According to another aspect of the disclosure, a reconfigurable fixture assembly is provided for an incremental forming fixture. In this embodiment, a binder has an opening that is divided by the clamp support segments to partition the opening. Smaller blanks may be supported by the fixture in the opening to reduce setup. Multiple blanks may be set in the fixture assembly at the same time. The clamp support segments partition the opening and are connected by a plurality of connecting members. The connecting members connect the clamp support segments that are disposed around a blank periphery. A clamping mechanism is provided on each of the clamp support segment to exert a clamping force on the blank. A reinforcement rod is attached to the clamp support segments, the connecting members, and the frame to support the blank within the binder opening. 
         [0009]    The above aspects of the disclosure and other aspects will be better understood in view of the attached drawings and the following detailed description of the illustrated embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of an incremental forming machine; 
           [0011]      FIG. 2  is a top view showing the fixture assembly with a single blank; 
           [0012]      FIG. 3  is a top view showing the clamp support segments and the connecting members retaining a blank that is smaller than the defined opening; 
           [0013]      FIG. 4  is a top view of the fixture assembly showing the clamp support segments, the connecting members, and the reinforcement rod assembled to the fixture assembly; 
           [0014]      FIG. 5  is a perspective view of a T-shaped connecting member; 
           [0015]      FIG. 6  is a perspective view of a corner connecting member; 
           [0016]      FIG. 7  is a perspective view of a cross connecting member; and 
           [0017]      FIG. 8  is an exploded perspective view of parts of the fixture assembly showing the clamp support segments, the connecting members, and the reinforcement rod. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The illustrated embodiments are disclosed with reference to the drawings. It should be understood that the disclosed embodiments are intended to be merely examples that may be embodied in various and alternative forms. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art how to practice the disclosed concepts. 
         [0019]    Referring to  FIG. 1 , a fixture assembly  10  is shown in an incremental forming machine  12 . The fixture assembly  10  is in a vertical position to allow multiple degrees of freedom motion devices such as multi-axis CNC machines or robots  14  to form both sides of a blank  16  at the same time or sequentially. 
         [0020]      FIG. 2  shows the fixture assembly  10  with a single blank  16  in a frame  18  that defines an opening  20 . A plurality of connecting members  22  connects a plurality of clamp support segments  24  around the periphery of the blank  16 ′. The fixture assembly  10  is shown supporting the blank  16  that fills the entire opening  20 . 
         [0021]      FIG. 3  shows a sub-frame assembly  26  that comprises a plurality of connecting members  22 , and clamp support segments  24 . The clamp support segments  24  each may support a clamp  27  for clamping a smaller blank  16 ′ within the sub-frame assembly  26 . A plurality of reinforcement rods  28  extend through and support the connecting members  22  and the clamp support segments  24  that subdivide the opening  20  into a plurality of smaller openings  20 ′. The sub-frame assembly  26  is secured to the frame  14  to facilitate forming the smaller blank  16 ′. 
         [0022]      FIG. 4  shows the fixture assembly  10  without the blank  16 ′ in the smaller opening  20 ′. The sub-frame assembly  26  extends across the frame  18  to partition the opening  20  into smaller openings  20 ′. Several blanks  16 ′ that have substantially different peripheries may be supported by the fixture assembly  10 . 
         [0023]      FIG. 5  shows a T-shaped border connecting member  30  that has three different connecting ends  32 . The T-shaped connecting members  30  define two holes  34 A and  34 B that receive a reinforcement rod  28 . Hole  34 A extends along an X-axis. Hole  34 B extends along a Y-axis that is perpendicular to the X-axis and are offset from each other in a Z-axis direction. Holes  34 A and  34 B are offset along the Z-axis so that the reinforcement rods  28  do not interfere with each other when assembled to the connecting members  30 . The connecting ends  32  also include a plurality of alignment pin holes  38 . The alignment pin holes  38  receive a plurality of alignment pins  40  to align the connecting members  30  and the clamp support segments  24  (shown in  FIGS. 2-4  and  8 ). The connecting ends  32  of the connecting members  30  may each receive a clamp support segment  24  at each connecting end  32 . 
         [0024]      FIG. 6  shows a corner connecting member  44  that has two connecting ends  32  and is adapted to receive two clamp support segments  24  (shown in  FIGS. 2-4  and  8 ). The corner connecting member  44  may be used to join two clamp support segments  24  at two connecting ends  32 . Similar to the T-shaped connecting member  30  shown in  FIG. 5 , the corner connecting member  44  also defines two holes  34 A and  34 B that extend along the X-axis and Y-axis directions. The holes are spaced apart along the Z-axis direction to ensure that the reinforcement rod  28  can extend through the connecting members without interference. 
         [0025]      FIG. 7  shows a cross connecting member  46  that has four connecting ends  32  for receiving up to four clamp support segments  24  (shown in  FIGS. 2-4  and  8 ). The cross connecting member  46  has four connecting ends  32  that are each adapted to receive one of the clamp support segments  24 . The cross connecting member  46  also has two receiving holes  34 A and  34 B that extend along the X-axis and Y-axis, respectively. The holes  34 A and  34 B are offset relative to each other in the Z-direction. The reinforcement rods  28  may be inserted through the connecting members  46  and the clamp support segments  24 . The reinforcement rods  28  support the sub-frame assembly  26  and make the sub-frame assembly  26  more rigid. 
         [0026]    Referring back to  FIGS. 2-3 , there are two distinct types of connecting members  22 . The T-shaped border connecting member  30  and the corner connecting members  44  may also be known as edge connecting members  48 . The edge connecting members  48  are disposed adjacent to the frame and allow the clamp support segments  24  to extend to the inner edge of the frame  18 . While these connecting members  44  are typically placed at or near the frame  18 , they can still be used within the opening  20 . The term edge connecting member  48  refers to the edge of the blank  16 ′, as these types of connecting members  48  are used to define support on all sides of the blank  16 ′. The cross connecting member  46  can also be used as an intermediate connecting member  50 . The intermediate connecting members  50  are connecting members  22  that are disposed within the opening  20  at a distance from the frame (shown in  FIG. 3 ). Intermediate connecting members  50  provide support in the space defined by the opening  20  (shown in  FIG. 3 ). Despite having different classifications and types, all connecting members  22  share the same purpose. All of the connecting members  22  are used to link the clamp support segments  24  such that the blank  16 ′ can be adequately supported on all sides. 
         [0027]      FIG. 8  is an exploded perspective view of the sub-frame assembly  26 . The sub-frame assembly  26  may extend across the entire opening  20  (shown in  FIGS. 2-4 ), or define a smaller opening  20  depending on the size of the blank  16 ′. The sub-frame assembly  26  may include several of the connecting members  30 ,  44  and  46 , the reinforcement rods  28 , the clamp support segments  24 , and the alignment pins  40 . The connecting members  30 ,  44  and  46  are aligned with the clamp support segments  24  by the alignment pins  40 . The reinforcement rod  28  is inserted into the holes  34 A and  34 B that extend through the length of the sub-frame assembly  26  when the clamp support segments  24  are aligned and assembled with the connecting members  30 ,  44 , and  46 . The reinforcement rod  28  is then fastened to the frame  18  (shown in  FIGS. 2-4 ) to support the clamps  27 . Each clamp  27  is secured to one of the clamp support segments  24  to hold the blank  16 ′ during the forming process. 
         [0028]    While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.