Abstract:
An integrated adjustable die fixture to be used to hold and stabilize large parts from dimensional fluctuation during the heat treating quenching process. The die fixture provides for a pair of interlocking dies each with a plurality of radially positioned interchangeable and configurable part engagement blades to conform and hold the part during quenching. A die fixture support and transport lifting frame selectively engages integrated die fixture and part for transport, positioning and select access to quenching furnace.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    This invention relates to heat treating of large parts such as steel rings and bearing races that require the parts to be heated and then quenched to impart case hardening. Such case hardening typically requires a two step process, gas carburizing and austenitizing. For gas carburizing, a steel part is heated to an elevated uniform temperature in a carbon-rich gas atmosphere. This allows the carbon in the atmosphere to diffuse into a layer at the surface of the part. 
         [0003]    During austenitizing (heat treating), a steel part is heated within the austenitizing range 1,455-1,680°, Fahrenheit, in a gas-fired integrated quenching furnace. The heated part is heated to a uniform temperature and then rapidly quenched in a medium, typically oil. This heating and rapid cooling imparts dimensional variations in such large parts and they will become out-of-round and out-of-flat, requiring the need initially to have extra stock in the part to be machined off and extra case depths to ensure sufficient case after machining. 
         [0004]    2. Description of Prior Art 
         [0005]    Prior art quenching methods and apparatus can be seen generally in U.S. Pat. Nos. 6,048,418; 8,034,258 B2; and EP 1,191,111 A1. 
         [0006]    Patent 6, 048,418 is directed to a ring-forming apparatus and heat treating process wherein flat ring parts are heated, then placed in a die and submerged in a quenching bath to form the ring into its final shape while therewithin. 
         [0007]    U.S. Pat. No. 8,034,285 B2 illustrates quenching methods and devices for quenching a steel ring which includes a corresponding set of quenching dies, a die handling tool, and related methods to lift the corresponding set of quenching dies and die handling apparatus to load and unload the dies into a quenching press. 
         [0008]    Finally, Patent EP 1,191,111 A1 discloses a method and apparatus for press tempering wherein a heated part is placed into a pressing device and then cooled with a coolant. 
       SUMMARY OF THE INVENTION 
       [0009]    A two-part die fixture system wherein each die has interchangeable die blades configured to conform to large work pieces to be positioned thereon and held therebetween when locked together. A lifting fixture of the system provides for selective engagement of the part independently and together for transport simultaneously to and from a quenching furnace, as well as part engagement and placement and removal from the die fixture. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective exploded view of the two-part die fixture locked together illustrating removable die blades selectively positioned thereon. 
           [0011]      FIG. 2  is an exploded perspective view of the die fixture and part to be placed and held thereon and therebetween. 
           [0012]      FIG. 3  is an exploded perspective view of the die fixture and part engaged by the lifting fixture for placement and removal together. 
           [0013]      FIG. 4  is a composite partial cross-section view of the two-part die fixture with a part positioned thereon. 
           [0014]      FIG. 5  is a top plan view of the lifting fixture independently of the die fixture. 
           [0015]      FIG. 6  is an enlarged partial sectional view of the part lifting arm adjustment support fitting on the lifting fixture. 
           [0016]      FIG. 7  is an enlarged partial side elevational view of the lifting arm adjustment of  FIG. 6  of the drawings. 
           [0017]      FIG. 8  is a graphic representation of a quenching furnace with a fixture engaged part positioned thereon for illustration purposes. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Referring now to  FIGS. 1 and 2  of the drawings, a die fixture assembly  10  of the invention can be seen having selectively engaged upper adjustable die  11  and a lower adjustable die  12 . Each of the adjustable dies  11  and  12  have an annular fixture base  11 A and  12 A of machined steel. Each of the annular fixture bases  11 A and  12 A have a plurality of threaded bores  13  positioned thereabout in spaced parallel to one another within the respective annular sidewalls  13 A and  13 B, best seen in  FIG. 1  of the drawings. The fixture bases  11 A and  12 A have respective top surfaces  11 B and  12 B and bottom surfaces  11 C and  12 C in spaced parallel relation to one another. 
         [0019]    A pair of center centralized bores at  14 A and  14 B extend respectively through the corresponding fixture bases  11 A and  12 A for receivable engagement of an enlarged locking pin  15  that extends from the fixture base  12 A, beyond its top surface  12 B for registration through the fixture base  11 A. 
         [0020]    The locking pin  15  has an extending tapered end portion  17  with an area of reduced annular dimension  18  there below. The locking pin  15  is aligned for registration with and through the bore  14 A in the fixture base  11 A and for selective engagement by a key lock yoke  19  which is slidably disposed on its top surface  11 B through a guide bracket  19 A shown in unlocked position in  FIG. 2  of the drawings, and a locked engaged position in  FIG. 1  of the drawings. 
         [0021]    Multiple die fixture lifting rings  20  are threadably secured in and extend from the top surface  11 B spaced annularly thereabout as will be discussed in greater detail hereinafter. 
         [0022]    A key element of the adjustable die fixture assembly are a plurality of interchangeable customizable die blades  21 , each having right angular edge base engagement  21 A and, in this example, an offset part engagement angular edge  21 B with spaced oppositely disposed respective parallel end edge surfaces  22 A and  22 B extending therefrom. 
         [0023]    Each of the interchangeable blades  21  are secured sequentially to the respective fixture bases respective annular sidewalls  13 A and  13 B by a pair of socket-head cap fasteners F that extend through corresponding aligned openings in their respective angular edge  21 B and right angled extending edge portion  23 , and threadably engaged into the hereinbefore described threaded bores  13  as best seen in  FIG. 4  of the drawings. This arrangement of individual mounted die blades  21  provide for adaptable interchangeable effective die surfaces which will accommodate therefore a wide variety of different configured parts  24 , illustrated in this example in  FIG. 2  of the drawings. 
         [0024]    Referring to  FIG. 3  of the drawings, a lifting fixture  30  can be seen engaging by the lifting rings  20  of the upper fixture base  11 A with multiple die blades  21  secured thereto. 
         [0025]    The lifting fixture  30  of the die fixture assembly  10  has a central hub  31  with an upstanding lifting ring  31 A extending therefrom. Multiple longitudinally extending fixture brackets  32 ,  33 , and  34 , extend from the central hub  31  in equal space radial relation to one another as best seen in  FIG. 5  of the drawings. Interconnecting braces  35  are secured between the respective brackets  32 ,  33 , and  34 , preferably by welding to their respective surfaces generally indicated at  32 A. Each of the braces  35  are apertured midpoint with an I-bolt assembly  36  extending therethrough which are in corresponding general alignment with the hereinbefore described die fixture lift rings  20 , which allow for selective interconnection thereto by multiple chain and hook assemblies  37  as seen in  FIG. 3  of the drawings. 
         [0026]    The fixture brackets  32 ,  33  and  34 , are preferably formed from pairs of paralleled spaced angle irons  38  and  39 , best seen in  FIGS. 3 and 6  of the drawings, each of which has an L-shaped end bracket  40  adjoining their respective free ends. The end brackets  40  are apertured at A with an I-bolt fitting  41  secured therethrough. Each of the lifting fixture brackets  32 ,  33  and  34 , has a lifting arm engagement assembly  42  thereon for longitudinal adjustment there along. The arm engagement assembly  42  is formed by an inverted U-shaped apertured support fitting  43  slidably engaged on a pair of oppositely disposed parallel guide tracks  44 A and  44 B that are secured to and extend outwardly from the vertical portions of the respective angle irons  38  and  39  as seen in  FIGS. 3 ,  6  and  7  of the drawings. 
         [0027]    Each of the U-shaped apertured support fittings  43  have a fixation set screw  45  therein that engages respective guide tracks  44 A locking the fitting  43  in position thereon. The foregoing arrangement allows for part size adjustment within a specific range as will be well understood by those skilled in the art. 
         [0028]    It will be seen that lifting arms  46  are pivotally secured within the apertured engagement support assemblies  42  by a pivot pin  46  extending therethrough in engageable alignment through the respective apertured U-shaped fitting  43 . The lifting arms  44  have a material engagement foot plate  47  that extends at right angles from their respective free ends as best seen in  FIG. 3  of the drawings. Each of the material plates  47  has a handle rod  49  extending therefrom arcuately up to its respective lift arm  44  which provides user directive material arm engagement and release during use. 
         [0029]    In use, the part  24  to be quenched is positioned on the plurality of interchangeable die blades  21  of each of the respective die fixture portions  11  and  12  and secured by sliding engagement of the locking yoke  19  for registration with the locking pin  15  as seen in  FIG. 4  of the drawings. 
         [0030]    The locked die assembly  10 A and part  24  positioned thereon is lifted by the lifting fixture  30  to an integrated quenching furnace  50  shown graphically for reference in  FIG. 8  of the drawings. The locked die assembly  10 A is released from lifting fixture  30  and is moved into the quenching furnace  50  and its heat inducing quenching sequence by submerging in hot quenching fluid  51 , as required in the heat treating process as understood by those skilled in the art. 
         [0031]    It will be evident from the above description that the die fixture assembly  10  of the invention comprising independent die bases  11 A and  12 A, each with interchangeable die blades  21  are therefore are conformable to specific large parts to be heat treated and the integrated integral lifting fixture  30  allows for carrying the heated part  25  and upper die base  11 A simultaneously, maintaining the part&#39;s temperature during placement. 
         [0032]    The ability to lift both the die and the part aligned with the unique interchangeable configurable die blades  21  assures that minimal part distortion will occur during the quenching process, eliminating the heretofore need for additional machining and thus the implied additional part material normally required due the necessity of the machining to overcome the out-of-flat or out-of-round nature implicit in the quenching process, especially in large parts, as hereinbefore described. It will thus be seen that a new and novel integrated size adjustable die fixture and fixture support and transport lifting assembly has been illustrated and described and will be apparent to those skilled in the art with various changes and modifications may be made thereto without departing from the spirit of the invention.