Patent Document

CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    U.S. Provisional Application for Patent No. 61/066,049, filed Feb. 15, 2008, with title “Quick Change Tool and Method for Die Casting Metal” which is hereby incorporated by reference. Applicant claim priority pursuant to 35 U.S.C. Par. 119(e)(i). 
     
    
       [0002]    Statement as to Rights to inventions made under Federally sponsored research and development: Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    This present invention relates to a method and system for casting metals. Aluminum, zinc and alloys for example are commonly die cast. Molten metal under high pressure is poured into a tool steel mold and when an aluminum part has cooled it is ejected from the tool steel mold. 
         [0005]    2. Background Information 
         [0006]    Parts can be cast from molten metal by sand casting or by die casting. Die casting has the advantage that many parts can be formed using a single tool. A disadvantage to die casting is the time it takes to set up a die for use. Typically a die is held in a casting machine that delivers molten metal under pressure to the die and provides the power to open the die and antomatically eject parts. A significant per piece cost of die casting products comes from the cost to build the die and then the set up required each time the die is used. Typically a die is bolted and pinned to the platen of a casting machine, the process of exactly positioning the heavy die on the platen is time consuming. The dies are heavy and can be damaged during the change over operation. 
         [0007]    Accordingly, there is a need for an improved tool and method for die casting. 
       SUMMARY OF THE INVENTION 
       [0008]    According to the present invention, a novel method and tool is provided for die casting. A quick change die casting tool set includes; 
         [0009]    a first plate frame bolted to an upper platen of a die casting machine; 
         [0010]    and a second plate frame bolted to a lower platen of a die casting machine. 
         [0011]    The first and second plate frames each can include a plurality of slotted die rails forming a rectangular plate frame having a slotted interior perimeter or groove. 
         [0012]    A first ear plate bolted to the top die shoe of a die set and a second ear plate is bolted to the bottom die shoe of a die set, wherein the first ear plate is sized to slidingly fit in the slotted interior perimeter and the second ear plate is sized to slidingly fit in the second slotted perimeter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a view of an embodiment of the present invention, a quick change tool for die casting metal. 
           [0014]      FIG. 2  shows details of the embodiment of  FIG. 1 . 
           [0015]      FIG. 3  shows a cross sectional view through the upper frame. 
           [0016]      FIG. 4  shows a second embodiment of the system open. 
           [0017]      FIG. 5  shows a partial view of the second embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    In accordance with the present invention, a quick change tool for casting metal is disclosed. The tool and method consists of components configured and correlated with respect to each other so as to attain the desired objective.  FIG. 1  shows a quick change die assembly  100  mounted in a mold machine  200 . The die assembly  100  mounts to the upper platen  200 A and the lower platen  200 B of a conventional die casting mold machine  200 . Clamps  102  hold bolts  104  used to mount the die assembly  100  to the upper  200 A and lower  200 B platens. The clamps  102 A hold an upper die shoe  110  to the upper platen  200 A. The upper die shoe  110  includes a slot  112  to accommodate each clamp  102 A. The lower die shoe  120  also includes a slot  122  around its perimeter to accommodate clamps  102 B. The upper die shoe  110  has upper die rails  130 ,  132 ,  134  and  136  bolted to it to form a plate like frame. The lower die shoe  120  has lower die rails  140 ,  142 ,  144  and  146  bolted to it to form a lower plate like frame. The die assembly  100  can include at least one manifold  150  for air, die lubricant and/or die coolant as required. 
         [0019]      FIG. 2  shows a partially disassembled view with the die rails  132  and  142  removed for disclosure. The die assembly  100  is shown open in the part ejection position. As can be seen, a conventional die set  300  is shown ready for use in the die assembly  100 . The conventional die set  300  includes a lower die shoe  310 , an upper die shoe  320 , and guides  330 . The upper die shoe  320  is bolted to an upper ear plate  340  and the lower die shoe  310  is bolted to a lower die ear plate  350 . The upper ear plate  340  is designed to slide into slots  131  and  134  in the upper die rails as shown as well as slots in two (2) other upper die rails  132  and  136 . Thus when installed, the peripheral edge of the rectangular upper ear plate  340  is held within the slots  131 ,  134  and the slots in the other two die rails  132  and  136 . 
         [0020]    Similarly, the lower die ear plate  350  periphery is held within lower die rail slots. Because molten metal is delivered under pressure, the upper die ear plate must be ground for a tight fit to the upper die shoe  110  and the upper die shoe  320 . Molten metal under pressure passes through the casting machine upper platen  200 A, through an opening in the upper die shoe  110 , through an opening in the upper ear plate  340  and into the die set  300 . 
         [0021]    The arrangement shows that a conventional die set  300  can be attached to upper and lower die ear plates  340  and  350  and the die ear plates are held in slots. Thus a conventional die set can be retrofit to fit into the upper frame  400  (See  FIG. 3 ) which includes the upper die shoe  110  and four (4) upper die rails  130 ,  132 ,  134  and  136  and a lower frame plate which includes the lower die shoe  120  and lower die rails  140 ,  142 ,  144  and  146 . A plurality of different die sets can be attached to ear plates  340 ,  350  such that dies can be quickly changed in and out of the system  100 . The upper and lower frames stay bolted in the casting machine platens  200 A and  200 B. The die ear plates  340  and  350  and slots  131 ,  134  and  141 ,  145  are precisely ground such that when a die  300  is slid into the upper and lower frames plates it will be quickly and precisely located which saves substantial time. 
         [0022]      FIG. 3  shoes a cross-sectional view of the upper frame  400 . The upper die shoe  110  includes an opening  410  that allows access to the die set  300  such that molten metal can be delivered to the interior space of the die set  300 . The upper ear plate  340  and upper die shoe  320  will also have openings aligned with the opening  410 . 
         [0023]    In use when it is time to perform a die change over, bolts holding rails  132  and  142  are removed so that the die rails  132  and  142  can be removed. Once the die rails  132  and  142  are removed, one of several eye bolts can be installed in holes such as  322  such that the die  300  can be slid out of the upper and lower frames and another die can then be installed. 
         [0024]      FIG. 4  shows a second embodiment of the die assembly  500 . The die assembly  500  is shown removed from the mold machine  200  and opened with an upper frame and die shoe of the die  502  on the left and a lower frame and die shoe  504  on the right. The upper frame and die shoe  502  includes four (4) guides  510  that cooperate with holes  512  in the lower frame and die shoe  504  to guide the die assembly as it opens and closes. The upper frame and die shoe  502  includes a parameter groove  505  that allows it to be attached to the upper platen of a die casting machine  200  (See  FIG. 1 ). The upper frame and die shoe  502  includes an upper die tool insert  520  that is held in place by bolt clamps  522  and parameter ear  531  that can be on three (3) sides of upper shoe  520 . The bolt clamps  522  bolt into the main upper die shoe frame plate  530 . The parameter ear  531  can be formed by a separate plate as in the first embodiment or it can be part of the upper die tool insert. The upper die shoe frame plate  530  includes an opening, shot hole similar to shot hole  410  (See  FIG. 3 ) that allows for molten metal to be injected into a shape to be molded inside the tool insert  520 . The insert of tool insert  520  is not shown and it will be understood that the tool insert will have a conventional mold shape in it. The tool insert  520  includes a threaded hole  532  that allows an eye bolt to be attached when it is time to remove the tool insert  520  from the upper die frame plate  530 . The upper die shoe  502  includes an upper portion  602  of spring loaded part ejector  600 . As can be seen, the slide unit part ejector  600  includes a rod  606  that cooperates in hole  608  in the lower portion  604  of the spring loaded part ejector  600 . The tilt of rod  606  creates motion as the machine  200  opens, the motion can be used to eject a part that has been cast. 
         [0025]    The lower die shoe  504  includes a lower tool insert  540  and a lower ejection insert  542  both held in place by bolt clamps  522 . The lower tool insert  540  and lower ejection insert  543  each include at least one threaded hole  532  to facilitate removal with an eye bolt. The lower tool insert  540  and lower ejection insert  542  are held in a slot in lower two (2) piece die shoe frame plate  536 . The parameter ear  533  holds the lower tool insert  540  and the parameter ear  534  holds the lower ejection tool  542 . The lower die shoe frame plate  536  includes a parameter groove  507  that allows it to be attached to a lower platen of a die casting machine. 
         [0026]      FIG. 5  shows the upper die body  530  and the lower die body  536  with the upper and lower tool inserts  520 ,  540 , the lower ejection insert  542  and the spring loaded part ejector  600  removed. As can be seen, what is left is a system of slotted openings that allow the die assembly  500  to be put together. The upper die frame plate  530  includes a slotted groove  550  that holds the upper tool insert  520  in place. Slots  522  and  554  hold the upper portions  602  of part ejector  600 . The upper die frame plate  530  includes a shot hole  560 . 
         [0027]    The lower die frame plate  536  includes an interior slotted groove  570  for the lower tool insert  540  and an interior slotted groove  572  for the lower ejection insert  542 . The lower die frame plate  536  also includes slots  580  and  582  that hold the lower portions  604  of spring loaded part ejector  600 . These slots  552 ,  554 ,  580  and  582  and slotted grooves  550 ,  570  and  572  provide exact placement of the tool inserts  520 ,  540  and  542  as well as location of the spring loaded ejector  600 . This allows for tool inserts  520 ,  540  and  542  to be inserted and removed from the die assembly  500  to create an inner changeable tool system. Tool change over simply requires the removal of both clamps  522  and the tool inserts  520 ,  540 ,  542  can be slid out. 
         [0028]    While the best mode for carrying out the invention has been described, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention. Thus, the above-described preferred embodiment is intended to be illustrative of the invention which may be modified within the scope of the appended claims.

Technology Category: b