Forging/coining method

Abstract

Methods for coining or forging powdered metal parts are disclosed. One example method uses a press including a first rod, a first ram surrounding the first rod, a die plate having a die cavity, a second rod opposite the first rod, and a second ram surrounding the second rod wherein the first rod and the second rod are dimensioned to fit within the inside diameter of the part. In the method, the part is positioned within the die cavity, one of the first rod and the second rod is located as a core rod within the inside diameter of the part, and at least one of the first ram and the second ram is moved toward the other of the first ram and the second ram such that both the first ram and the second ram contact and coin or forge the wall of the part.

1 . A method for coining or forging a part, the method comprising: 
 providing a press including a core rod, a ram surrounding the core rod, and a die plate having a die cavity wherein the core rod is dimensioned to fit within an inside diameter of the part;    positioning the part within the die cavity;    locating the core rod within the inside diameter of the part;    moving the ram such that the ram contacts and coins or forges the part; and    oscillating the core rod within the part before removing the core rod from the part.    
     
     
         2 . The method of  claim 1  wherein: 
 the part is a gear having an inside surface with helical teeth,    the core rod is rotatable, and    the core rod has an outer surface with helical ribs dimensioned to be slidingly complementary to the helical teeth of the gear.    
     
     
         3 . The method of  claim 2  further comprising: 
 providing the press with a second core rod, the second core rod being rotatable and having an outer surface with helical ribs dimensioned to be slidingly complementary to the helical teeth of the gear;    locating the second core rod within the inside diameter of the part; and    oscillating the second core rod within the part before removing the second core rod from the part.    
     
     
         4 . The method of  claim 1  further comprising: 
 providing the press with a second ram; and    moving the ram and the second ram toward each other such that both the ram and the second ram contact and coin or forge the part.    
     
     
         5 . The method of  claim 1  further comprising: 
 extending a lower end of the core rod beyond a lower end of the ram;    locating the lower end of the core rod within the inside diameter of the part; and    positioning the part within the die cavity by way of the first rod.    
     
     
         6 . The method of  claim 1  further comprising: 
 providing the press with a second core rod;    locating the second core rod within the inside diameter of the part;    oscillating the second core rod within the part before removing the second core rod from the part.    
     
     
         7 . The method of  claim 1  further comprising: 
 providing the press with a second core rod, the second rod having an outside diameter less than an outside diameter of the core rod.    
     
     
         8 . The method of  claim 1  further comprising: 
 providing the press with a second core rod,    wherein the part includes a second inside surface having a diameter less than a diameter of the inside surface of the part, and the second core rod is dimensioned for sliding fit within the second inside surface of the part.    
     
     
         9 . The method of  claim 1  wherein: 
 the part is a powdered metal part.    
     
     
         10 . A method for coining or forging a part, the method comprising: 
 providing a press including a ram and a die plate having a die cavity;    positioning the part within the die cavity;    moving the ram such that the ram contacts the part; and    oscillating the ram when the ram contacts the part to coin or forge the part.    
     
     
         11 . The method of  claim 10  further comprising: 
 providing the press with a second ram;    moving the second ram such that the second ram contacts the part; and    oscillating the second ram when the second ram contacts the part to coin or forge the part.    
     
     
         12 . The method of  claim 11  wherein: 
 the ram and the second ram are dimensioned to fit within the die cavity.    
     
     
         13 . The method of  claim 10  further comprising: 
 providing the press with a core rod dimensioned to fit within an inside diameter of the part; and    locating the core rod within the inside diameter of the part.    
     
     
         14 . The method of  claim 10  further comprising: 
 providing the press with a second ram,    wherein the part has an outwardly extending flange on an end of the part, and the second ram has an outside diameter substantially equal to an outside diameter of the flange, and the second ram moves toward the ram such that both the ram and the second ram contact and coin or forge the part.    
     
     
         15 . The method of  claim 10  wherein: 
 the part is a powdered metal part.    
     
     
         16 . A method for coining or forging a part, the method comprising: 
 providing a press including a ram, a die plate having a die cavity, and means for varying pressing rates of the ram;    positioning the part within the die cavity;    moving the ram such that the ram contacts the part; and    varying a pressing rate of the ram after the ram contacts the part to coin or forge the part.    
     
     
         17 . The method of  claim 16  wherein: 
 the means for varying pressing rates comprises a processor in communication with a hydraulic system for controlling downward and upward movement of the ram.    
     
     
         18 . The method of  claim 17  further comprising: 
 providing the press with a core rod dimensioned to fit within an inside diameter of the part;    providing the press with means for varying downward and upward movement rates of the core rod;    locating the core rod within the inside diameter of the part before or after positioning the part within the die cavity; and    varying downward and upward movement rates of the core rod within the inside diameter of the part.    
     
     
         19 . The method of  claim 18  wherein: 
 the means for varying downward and upward movement rates comprises the processor in communication with a hydraulic system for controlling downward and upward movement of the core rod.    
     
     
         20 . The method of  claim 19  further comprising: 
 providing the press with a second core rod opposite the core rod and with a second ram surrounding the second core rod wherein the core rod surrounds the ram, and the core rod and the second rod are dimensioned to fit within the inside diameter of the part;    locating the core rod and the second core rod within the inside diameter of the part;    moving the ram and the second ram toward each other such that both the ram and the second ram contact and coin or forge the wall of the part.    
     
     
         21 . The method of  claim 20  wherein: 
 the ram and the second ram are dimensioned to fit within the die cavity.    
     
     
         22 . The method of  claim 20  wherein: 
 the core rod and the second core rod are rotatable.    
     
     
         23 . The method of  claim 16  wherein: 
 the part is a powdered metal part.