Patent Publication Number: US-9409222-B2

Title: Reducing waste in metal stamping processes and systems therefor

Description:
FIELD 
     The present disclosure relates to devices and methods for reducing waste in metal stamping lines. 
     BACKGROUND 
     The cost of materials in the metal industry, such as flat rolled steel, has been increasing, rapidly given the world supply and demand as well as increasing energy costs required to produce various metal products. Between 2003 and 2009 the average steel price has increased by about three times and is projected to increase about an additional 15% by 2011; far exceeding the anticipated rate of inflation. 
     When sheet metal blanks are used to produce stamped metal parts, excess material is required about the perimeter of the blank. This excess material is known as the addendum and is used as a region for clamping and maintaining the blank in place during the stamping process. Ultimately the addendum is removed from the final part and scrapped. 
     Since the addendum is not integral to the final part resulting from the stamping process and is ultimately removed as scrap, it would be desirable to develop a device and method for holding a blank in place during the stamping process which requires a smaller amount of addendum material. Additionally, it would be desirable to develop a device and method where the portion of the blank which is used to hold the blank in place during the stamping process remains in the final part. A smaller amount of addendum material would result in lower material input cost and less scrap resulting from the stamping process. For example, in the automotive industry, reducing size of the blank addendum required to form the final part by merely 10% may result a material cost savings of millions of dollars per year. 
     SUMMARY OF THE GENERAL INVENTIVE CONCEPT 
     The following presents a simplified summary of the general inventive concept herein to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to restrict key or critical elements of the invention or to delineate the scope of the invention beyond that explicitly or implicitly described by the following description and claims. 
     In an exemplary embodiment, there is provided a stamping device for stamping a metal blank, comprising a first die section and a second die section. The first and second die sections include complementary first and second surface portions with respective first and second work piece-forming regions located thereon where each of the first and second surface portions have substantially coextensive boundary portions. The first and second die sections are operable for movement along a travel path relative each other between a retracted position and a stamping position where, when in the stamping position, the first and second surface portions are in communication. The first and second work piece-forming regions are arranged for shaping a work piece from a metal blank within the boundary portions when the die sections are in the stamping position. An intermediate clamp section located intermediate the first and second die sections for engaging the first die section at a clamping position is provided. The first die section and the intermediate clamp section include respective first and second clamping formations for clamping the blank. The intermediate clamp section includes a peripheral region with a plurality of projections extending inwardly therefrom and the second die section has cut-out regions for receiving a corresponding projection. The first die section is movable relative to the second die section from the retracted position to the clamping position before reaching the stamping position so as to clamp the blank between the first die section and the intermediate clamp section. The intermediate clamp section is operable for travel with the first die section relative to the second die section, to the stamping position so as to nest with the second die section with the projections resident in the corresponding cut-out regions. 
     In some exemplary embodiments, the second surface portion has at least one support portion, slidably extending therethrough, for supporting the blank prior to clamping. Furthermore, in various exemplary embodiments, the supporting portion is movable relative the second die section wherein the second die section is operable for travel to the stamping position so as to disengage the blank and the supporting portion. 
     In some exemplary embodiments, the projections are oriented so as not to interrupt the second work piece-forming region. In other exemplary embodiments, the projections may be oriented so as to interrupt the second work piece-forming region. 
     In some exemplary embodiments, the clamping formations are shaped to form retention beads on a peripheral scrap region in the blank which is spaced from the work piece. In other exemplary embodiments the clamping formations may be continuous with the piece-forming regions. 
     In some exemplary embodiments, the first die section and the intermediate clamp section further comprise at least respective third and fourth clamping formations for clamping various sizes of blanks. 
     In some exemplary embodiments, the intermediate clamp section includes a trim line cutter. 
     In some exemplary embodiments, the intermediate clamp section further comprises a blank shifting member operable for aligning the blank for clamping with first and second clamping formations and/or the third and fourth clamping formations. In various exemplary embodiments, the blank shifting member is an actuated member suitable for aligning and maintaining the blank in a desired clamping position. Furthermore, in various exemplary embodiments, the actuated member is a hydraulic cylinder with a piston carrying an effector operatively coupled to the intermediate clamp section such that the piston may align and maintain the blank in the desired clamping position. 
     In another exemplary embodiment, there is provided a method for reducing the required length of a blank to produce a stamped part therefrom. The method comprises the steps of:
         a) placing the blank between a first die section and second die section with the die sections in a retracted position;
           the first and second die sections being operable for movement along a travel path relative each other between the retracted position and a stamping position;   the first and second die sections including complementary first and second surface portions with respective first and second work piece-forming regions located thereon;   the first and second work piece-forming regions being arranged for shaping a work piece from a metal blank within boundary portions in the stamping position;   an intermediate clamp section located intermediate the first and second die sections for engaging the first die section at a clamping position;   the intermediate clamp section including a peripheral region with a plurality of projections extending inwardly therefrom and the second die section having cut-out regions, each cut-out region for receiving a corresponding projection;   the first die section and the intermediate clamp section including respective first and second clamping formations for clamping the blank;   
           b) aligning the blank with the clamping formations;   c) causing the first die section to travel relative to the intermediate clamp section to engage the blank therebetween for clamping the blank therebetween;   d) causing the first die section and the intermediate clamp section to travel relative to the second die section with each projection being received in a corresponding cut-out region on the second work piece-forming region so as to communicate with the first work-piece forming region in a stamping position so as to form a stamped part; and   f) removing the stamped part from between the die sections.       

     Some exemplary embodiments further comprise utilizing respective third and fourth clamping formations on the first die section and the intermediate clamp section at least for clamping blanks of different sizes. 
     Still some exemplary embodiments further comprise utilizing a blank shifter for aligning the blank in step (b) for clamping with the first and second clamping formation and/or the third or fourth clamping formations. 
     In some exemplary embodiments, the blank is of a first length for clamping with the first and second clamping formations and/or the third and fourth clamping formations, or of a second length for clamping with the third and fourth clamping formations. 
     In some exemplary embodiments, the method may further comprise cutting the stamped part along a trim line so as to sever a peripheral scrap region from the final part 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Several exemplary embodiments will be provided, by way of examples only, with reference to the appended drawings, wherein: 
         FIG. 1 a    is a perspective view of a stamping device embodiment for reducing the amount of addendum material; 
         FIG. 1 b    is an end view on an embodiment of  FIG. 1   a;    
         FIG. 2 a    is an operational perspective view of an embodiment of the device of  FIG. 1 a    in a clamping position; 
         FIG. 2 b    is an end view of  FIG. 2   a;    
         FIG. 2 c    is an operational perspective view of an embodiments of  FIG. 2 a    in a stamping position; 
         FIG. 2 d    is an end view of  FIG. 2   c;    
         FIG. 2 e    is an operational perspective view of an embodiment of the device of  FIG. 2 a    following a stamping action; 
         FIG. 2 f    is a an end view of  FIG. 2   e;    
         FIG. 3 a    is an operational perspective view of an embodiment of the device of in a clamping position; 
         FIG. 3 b    is an end view of  FIG. 3   a;    
         FIG. 3 c    is an operational perspective view of  FIG. 3 a    in a clamping position and the second die section moving to a stamping position; 
         FIG. 3 d    is an operational perspective of an embodiment of  FIG. 3 a    in a stamping position; 
         FIG. 3 e    is an end view of  FIG. 3   d;    
         FIG. 3 f    is an operation perspective view of an embodiment of the device of  FIG. 3 a    following a stamping action; 
         FIG. 3 g    is an end view of  FIG. 3   f;    
         FIG. 4 a    is a perspective view of an embodiment of the device of  FIG. 1 ; 
         FIG. 4 b    is a perspective view of the device of  FIG. 4 a    with the die sections in a retracted position and a stamped part therebetween; 
         FIG. 5 a    is a perspective of another embodiment of the device; 
         FIG. 5 b    is a end view of  FIG. 5   a;    
         FIG. 5 c    is a perspective view of the device of  FIG. 5   a;    
         FIGS. 6 a  and 6 b    are perspective views of embodiments the intermediate clamp section and various clamping formations: 
         FIG. 7 a    is perspective view of an embodiment of an intermediate clamp section with a blank shifting mechanism coupled thereto; 
         FIG. 7 b    is a perspective view of an embodiment of the device with the blank shifting mechanism interacting with a blank atop the intermediate clamp sections; 
         FIG. 8 a    is a perspective view of an embodiment of the device with the support portion supporting a blank and with the die sections in a retracted position; 
         FIG. 8 b    is a perspective of the device of  FIG. 8 a    with the support portions receded into the second die section and the first and section die section in a stamping position; 
         FIG. 9  is a fragmented perspective view of an embodiment of a second die section and an intermediate clamp section with the projections nested in the cut-out regions; 
         FIG. 10 a    is a fragmented perspective view of another arrangement of an embodiment of a second die section and an intermediate clamp section; and 
         FIG. 10 b    is a fragmented perspective view of a variation of the arrangement shown in  FIG. 10   a.    
     
    
    
     DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     It should be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings. Furthermore, and as described in subsequent paragraphs, the specific mechanical, other configurations illustrated in the drawings are intended to show exemplary embodiments. However, other alternative mechanical or other configurations are possible which are considered to be within the teachings of the instant disclosure. 
     With reference to the figures, there is provided a stamping device  10  for stamping a metal blank  12  to produce a stamped part  14 . The device  10  as described herein may allow the use of a smaller blank  12  as compared to conventional stamping devices. The device  10  comprises a first die section  16  and a second die section  18 . The first die section  16  includes a first surface portion  20  having a first work piece-forming region  22 . The second die section  18  includes a second surface portion  24  and a second work piece-forming region  26 . The first surface portion  20  and the second surface portion  24  as well as the first work piece-forming region  22  and the second work piece-forming region  26  are respectively substantially complementary. Located between the first  16  and second  18  die sections is an intermediate clamp section  28  comprising clamp modules  29  (see  FIG. 2 a   ) for engaging with the first die section  16  at a clamping position as shown in  FIGS. 2 a , 2 b , 3 a    and  3   b.    
     The die sections  16  and  18  have boundary portions  42  located near the respective perimeters for aligning a blank  12  between the die sections  16  and  18 . The boundary portions  42  are substantially co-extensive. 
     With reference to  FIGS. 1 a  and 1 b   , the first die section  16  includes one or more first clamping formations  30 , each of which is substantially complementary with a second clamping formation  32  located on the intermediate clamp section  28 . In various other exemplary embodiments, the first die section  16  and the intermediate clamp section  28  may comprise additional or secondary complementary clamping formations for accommodating blanks  12  of various sizes to be stamped in the device  10 . For example, as seen in  FIG. 6 b   , the additional clamping formations may include one or more fourth clamping formations  36  located on the intermediate clamp section  28 , and one or more third clamping formations  34  located on the first die section  16 , as shown in  FIG. 2 e   . Additionally, the shape of the clamping formations  30  and  32 , and in some exemplary embodiments the third and fourth formations  34  and  36 , may vary depending on the desired contour of the stamped part  14 . For example, as shown in  FIGS. 4 a  and 4 b   , the first clamping formation  30  may be provided as an elongate depression with the second clamping formation  32  being provided as a protrusion (not shown) complementary to the first clamping formation  30 . Accordingly, an elongate retention bead  52  is formed in the stamped part  14  as shown in  FIG. 4 b   . In this case, the retention bead  52  is shown as a discrete formation a distance from the two elongate floor panel stamped sections  45 . The retention bead  52  may, alternatively be structurally continuous with the other non-planar structures of the stamped part  14 , for example the two elongate floor panel sections  45  (not shown). The retention bead or beads  52  may be included in the stamped part  14  or removed as a peripheral scrap region  47  in the addendum material  46  as shown, for example, in the exemplary embodiment in  FIG. 3   f.    
     As shown in the figures and with particular reference to  FIG. 1 a   , the intermediate clamp section  28  includes projections  38  which extend inwardly and are respectively received in cut-out regions  40  located in the second die section  18 . The clamping formations  32  are thus located on the projections  38  of the intermediate clamp formation  28 . In a clamping position, as shown for example, in  FIGS. 2 a , 2 b   , the clamping formations  30  and  32  (not visible in the figure view) mate with the blank  12  therebetween so as to hold the blank  12  in place during the stamping process. The secondary clamping formations  34  and  36 , in various other embodiments may function similarly to enhance the clamping of a blank  12  in place during the stamping process, or to allow for clamping a blank of a different size. 
     In operation, the first die section  16  or the second die section  18 , or both, are operable for movement along a travel path relative to each other between a retracted position and a stamping position. As noted above, the intermediate clamp section  28  is located between the first and second die sections  16  and  18  when the die sections are in a retracted position as shown in  FIG. 1 a   . The first die section  16  and the intermediate clamp section  28  are movable relative each other from the retracted position to the clamping position as shown in  FIGS. 2 a , 2 b   , so as to clamp the blank  12  between the first die section  16  and the intermediate clamp section  28 . The first die section  16  and the intermediate clamp section  28  are operable for travel together relative the second die section  18 , such that the stamped part  14  is formed by the mating of the first work piece-forming region  22  and the second work piece-forming region  26  with the die sections  16  and  18  in the stamping position and the blank  12  maintained in position therebetween, as shown in  FIGS. 2 c , 2 d   . In this case, the projections  38  nest with the corresponding cut-out regions  40 .  FIGS. 2 e , 2 f    show an exemplary resultant stamped part  14  following the stamping operation with the intermediate clamp section  28  and the first  16  and second  18  die sections in a retracted position.  FIG. 9  shows an embodiment of the second surface portion  24  and the second work piece-forming region  26  with the projections  38  nested in the cut-out regions  40 . The second clamping formations  32  are noted on the projections  38 . As shown in  FIGS. 2 e  and 2 f   , once the stamped part  14  is formed, the die sections  16  and  18  separate and the now formed stamped part  14  is released from the clamping formations  30  and  32 . 
     With reference to  FIGS. 1 a  and 1 b   , in operation of the device  10 , a blank  12  is placed between the first and second die sections  16  and  18  in a retracted position and confined by the boundary portions  42  to align the blank  12  in place. The first die section  16  and the intermediate clamping section  28  are moved toward each other as shown in  FIGS. 2 a , 2 b   , such that this blank is clamped between the first die section  16  and the intermediate clamp section  28 . The first clamp formation  30  and the second clamp formation  32  communicate to maintain the blank  12  in the desired position in the clamping position. The first and second die sections  16  and  18  are then moved towards each other such that the first work piece-forming region  22  and the second work piece-forming region  26  communicate in a stamping position, as shown in  FIGS. 2 c , 2 d , 3 c , 3 d  and 3 e   . In the stamping position, the stamped part  14  is formed by the interaction of the work piece-forming regions  22  and  24  with the blank  12  clamped by the clamping formations  30  and  32 . As shown in  FIG. 2 c   , the projections  38  nest within the cut-out regions  40  of the second die section  18 .  FIGS. 2 e , 2 f    show the first and second die sections  16  and  18  in a retracted position with the projections  38  resident in the cut-out regions  40  so as to release the stamped part  14  from the device  10 . 
     By placing the second clamping formations  32  on the projections  38  as shown specifically in  FIG. 6 a   , a smaller blank  12  may be able to be used in the stamping device  10  than as conventionally possible. The placement of the second clamping formations  32  on the projections  38  allows the blank  12  to be clamped between the intermediate clamp section  28  and the first die section  16  prior the first and second work piece-forming regions  22  and  26  engaging the blank  12 . By way of example, the blank  12  is then held substantially securely in place such that when the first and second work piece-forming regions  22  and  26  engage the work piece in the stamping position as shown in  FIGS. 2 c , 2 d   , the blank  12  remains in the desired position. Furthermore, the portion of the blank  12  which is grasped by the first and second clamping formations  30  and  32 , and thus the formed retention beads  52 , may be located within the area occupied by the stamped part  14  following the stamping process. 
     The clamping formations  30  and  32  thus form a retention bead  52  in the stamped part  14 . In some cases, the retention beads  52  may be located inside a trim line  54  and thus remain in the final stamped part  14  as shown in  FIGS. 2 e , 2 f , 4 b  and 5 c   . In other words, the clamping formations, in this case, can be formed to be continuous with the structural piece-forming regions so as to appear in the finished part. For instance, if the finished part is a floor panel  45 , the clamping formations may take the form of reinforcement beads or the like for the finished floor panel  45  In other cases the projections  38 , as shown in  FIGS. 3 a , 3 f  and 3 g    may include a trim line cutter  55  to cut along the trim line  54  during the stamping process. In this case, the retention bead  52  may be located in the peripheral scrap region  47  of the addendum  46 , outside the trim line  54  as shown in  FIG. 3   f.    
       FIGS. 5 a  to 5 c    show a variation of the device in which the intermediate clamp section provides a pair of clamp modules  32  each itself forming a singular projection  38  and dimensioned to fit within a singular cut out region  40  in the section die section  18 .  FIG. 5 c    in this case also illustrates, schematically, a step of removing the addendum  46 , which may occur during the stamping step or in a later step. 
     A blank shifting member  44  may also be provided in various embodiments as shown in  FIGS. 7 a  and 7 b   . In this example, the blank shifter  44  is located on the intermediate clamp section  28  and is operable for aligning the blank  12  with the first and second clamping formation  30  and  32  or the third and fourth clamping formations  34  and  36 . In various operations, such as producing as floor panel member  45  for an automobile, it may be desirable to employ the same first and second work piece-forming regions  22  and  26  for producing a stamped part  14  for either a 2-door or 4-door automobile. However, the floor panel member  45  may be shorter in overall length in the 2-door version. An exemplary blank  12  having a second length is shown for a 2-door automobile in  FIG. 10 a    at  58 . In the case of the 2-door exemplary embodiment, the blank shifter  44  may be used to push the blank  12  between the first die section  16  and the second die section  18  in the retracted position to align the blank  12  for clamping using the third and fourth clamping formations  34  and  36  as shown in  FIG. 10 a   . The blank  12 , in this position is confined by the boundary portions  42 . In another exemplary embodiment, such as in the case of a 4-door automobile, a longer blank  12  has a first length as shown in  FIG. 10 b    at  60  may be required owing to a longer floor panel section being required. The blank shifter  44  similarly aligns this longer blank  12 , for use with the first and second clamping formations  30  and  32 . In the case of the use of a longer blank having a first length  60 , the third and fourth clamping formations  34  and  36  may also engage the longer blank  60 . Thus, the versatility of the device  10 , in various embodiments, allows for the use of different sized blanks  12 , for example a 2-door automobile-sized blank  58  and as well as a 4-door automobile-sized blank  60  as noted above with the same first and second die sections  16  and  18  thereby reducing the amount of addendum material  46  needed. 
     In some exemplary embodiments, the blank shifting member  44  is provided atop the intermediate clamp section  28  as shown in  FIGS. 7 a  and 7 b   . The blank shifter  44  may be an actuated member, for example a hydraulic cylinder  48  (or solenoid) and operable piston  50 , with distal end carrying an end effector  51 . The hydraulic cylinder  48  may be coupled to the intermediate clamp section  28  and oriented such the operable piston  50  and effector  51  is able to the push the blank  12  into the desired position with the first and second die sections  16  and  18  in the retracted position as shown in  FIG. 7 b   . Various other means of aligning various blank sizes with corresponding clamping formations may also be used. 
     Referring to  FIG. 8 a   , at least one support portion  56  may be included in some exemplary embodiments for supporting the blank  12  between the first and second die sections  16  and  18  in the retracted position as shown. Sheet metal blanks  12  are known to be flexible. The size of the addendum  46  is smaller in blanks  12  that may be used with the device  10 , as noted above. Due to the flexibility of sheet metal blanks, a smaller blank  12  may be prone to fall to the second surface portion  24  prior to the engagement of the clamping formations  30 ,  32 ,  34  and/or  36 . Therefore, the support portion or support portions  56  may substantially inhibit the blank  12  from falling into the second surface portion  24 . The support portion  56  slidably extends through the second die section  18  and emerges through the second surface portion  24  substantially level with the intermediate clamp section  28 , as shown  FIG. 8 a   . The support portion  56  is thus able to support the blank  12  when the first and second die sections  16  and  18  are in the retracted position. In operation, as the intermediate clamp section  28  moves relative the first die section  16  to engage the clamping formations and clamp the blank  12  in place for stamping the blank  12 , the support portion  56  is no longer required. In other words, once the blank  12  is clamped in the desired position, the blank  12  is supported by the clamping action of the clamping formations  30 ,  32 ,  34  and/or  36 . The second die section  18  then, as noted above, moves relative the first die section  16  and the intermediate clamp section  28  to the stamping position as shown in  FIG. 8 b   . Thus, the support portions  56  may be configured to recede relative the second surface portion  24 , so as to not interfere with the stamping process. The stamped part  14  may thus be formed between the first and second work piece-forming, regions  22  and  26 . 
     In some exemplary embodiments the support portion  56  may be provided in the form of a plurality of support pins  56 . Additionally, a grouping of support pins  56  may be located in the a peripheral scrap region  47  of the addendum  46  areas such they support the blank  12  in the regions that may not be included in the final stamped part  14 . 
     Thus, in some examples, by combining a blank shifter  44  as shown in  FIGS. 7 a  and 7 b   , along with stepped-in draw bead formations  30 ,  32 ,  34  and  36  and blank support pins  56 , the size of the blank  12  required to produce stamped part  14  therefrom may be reduced. The reduction in the size of the blank  12  required for use in the device  10  may realize material input savings and thus increasing the material yield. By way of providing the stepped draw bead formations  30 ,  32 ,  34  and/or  36  to initially clamp a blank  12  in place prior to stamping using an intermediate clamp section  28  in communication with a first die section  16 , less addendum  46  material is needed to hold the blank  12  in place during stamping. A similar final part  14  may be produced as using convention stamping devices; however less blank material is required. In some embodiments, the amount of blank material required may be reduced. 
     Furthermore, in some embodiments, the draw beads  52  may remain in the final part  14  as shown, for example, in  FIGS. 2 e , 2 f , 3 f , 3 g , 4 b  and 5 c   . The lower blank holder  28  and the upper die  16  move relative each other to clamp the blank  12  as shown  FIGS. 2 a  and 5 a   . The lower die  18  then engages the blank  12  and the panel  14  is formed around the lower die  18  by complementary work piece-forming regions  22  and  26  as shown in  FIGS. 2 c  and 2 d   . The work piece-forming regions  22  and  26  are located on the upper and lower die sections  16  and  18  respectively. 
     Those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof of parts noted herein. While the stamping device  10  for stamping a sheet metal blank  12  and a method has been described for what are presently considered the exemplary embodiments, the present disclosure is not so limited. To the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.