Zoning closed-die extruding device and method

Abstract

A zoning closed-die extruding device comprises a closed female die and a male die. which is disposed in a longitudinal direction and configured to be mated with a closed cavity of the closed female die to extrude a blank. The male die comprises an extruding shaft portion and a stamp-extruding head portion, which is connected with the extruding shaft portion and disposed below the extruding shaft portion. A cross-sectional area of the stamp-extruding head portion perpendicular to a longitudinal axis of the closed female die is smaller than that of the extruding shaft portion perpendicular to the longitudinal axis of the closed female die. The male die is configured to rotate about the longitudinal axis of the closed female die so that the blank is sequentially and zonally deformed by the stamp-extruding head portion inside the closed cavity of the closed female die.

1 . A zoning closed-die extruding device, comprising:
 a closed female die; and   a male die disposed in a longitudinal direction and configured to be mated with a closed cavity of the closed female die to extrude a blank, wherein   the male die comprises:
 an extruding shaft portion; and 
 a stamp-extruding head portion connected with the extruding shaft portion and disposed below the extruding shaft portion, in which a cross-sectional area of the stamp-extruding head portion perpendicular to a longitudinal axis of the closed female die is smaller than that of the extruding shaft portion perpendicular to the longitudinal axis of the closed female die; and 
   the male die is configured to rotate about the longitudinal axis of the closed female die so that the blank is sequentially and zonally deformed by the stamp-extruding head portion inside the closed cavity of the closed female die.   
     
     
         2 . (canceled) 
     
     
         3 . The zoning closed-die extruding device of  claim 1 , wherein the extruding shaft portion comprises:
 a cylindrical shaft portion; and   a flange portion formed between a lower part of the cylindrical shaft portion and the stamp-extruding head portion, in which the cross-sectional area of the stamp-extruding head portion perpendicular to the longitudinal axis of the closed female die is smaller than that of the flange portion perpendicular to the longitudinal axis of the closed female die.   
     
     
         4 . The zoning closed-die extruding device of  claim 1 , wherein the extruding shaft portion and the stamp-extruding head portion are integrally formed, or the closed female die is a prestressed extrusion die, and an inner diameter of the closed cavity of the prestressed extrusion die is greater than a maximum radial dimension of the extruding shaft portion and the stamp-extruding head portion. 
     
     
         5 . The zoning closed-die extruding device of  claim 1 , wherein a cross section of the stamp-extruding head portion in a plane perpendicular to the longitudinal axis of the closed female die is of a rectangle shape, a long edge of the rectangle equals to a diameter of the extruding shaft portion, and a ratio of a short edge of the rectangle to the long edge thereof ranges from about 0.05 to about 0.95. 
     
     
         6 . The zoning closed-die extruding device of  claim 1 , wherein a ratio of the cross-sectional area of the stamp-extruding head portion to the cross-sectional area of the extruding shaft portion is within a range of about 0.1 to about 0.9. 
     
     
         7 . The zoning closed-die extruding device of  claim 1 , wherein during extruding, an extrusion force applied to the male die is adapted to a width of the stamp-extruding head portion and a diameter of the extruding shaft portion, or a central portion of the stamp-extruding head portion is formed with a recess portion. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . A zoning closed-die extruding method, comprising:
 (1) placing a blank formed with a central hole having a predetermined depth in a closed female die and heating the blank to a temperature suitable for closed die forging; and   (2) sequentially and zonally extruding the blank in the closed female die using a male die which is rotatable about a longitudinal axis of the closed female die, wherein the male die comprises:   an extruding shaft portion; and   a stamp-extruding head portion connected with the extruding shaft portion and disposed below the extruding shaft portion, in which a cross-sectional area of the stamp-extruding head portion perpendicular to the longitudinal axis of the closed female die is smaller than that of the extruding shaft portion perpendicular to the longitudinal axis of the closed female die.   
     
     
         11 . The zoning closed-die extruding method of  claim 10 , wherein the step (2) comprises:
 (2.1) extruding the blank along the central hole using a predetermined extrusion force;   (2.2) raising the male die for restoration;   (2.3) rotating the male die about the longitudinal axis of the closed female die through a predetermined angle; and   (2.4) repeating the steps (2.1), (2.2) and (2.3).   
     
     
         12 . The zoning closed-die extruding method of  claim 10 , wherein a central portion of the stamp-extruding head portion is formed with a recess portion. 
     
     
         13 . The zoning closed-die extruding method of  claim 10 , wherein the extruding shaft portion comprises:
 a cylindrical shaft portion; and   a flange portion formed between a lower part of the cylindrical shaft portion and the stamp-extruding head portion, in which the cross-sectional area of the stamp-extruding head portion perpendicular to the longitudinal axis of the closed female die is smaller than that of the flange portion perpendicular to the longitudinal axis of the closed female die.   
     
     
         14 . The zoning closed-die extruding method of  claim 10 , wherein in the step (2), an extrusion force applied to the male die is adapted to a width of the stamp-extruding head portion and a diameter of the extruding shaft portion, and/or the extrusion force is about 1000 MN to about 1500 MN. 
     
     
         15 . (canceled) 
     
     
         16 . The zoning closed-die extruding method of  claim 10 , further comprising:
 (3) finishing an inner surface of the sequentially and zonally extruded blank in the step (2) along the central hole of the blank using a finishing extrusion shaft so that the blank has an even wall thickness.   
     
     
         17 . The zoning closed-die extruding method of  claim 16 , wherein the step (2) and the step (3) are alternately performed to extrude the blank. 
     
     
         18 . The zoning closed-die extruding method of  claim 11 , wherein the predetermined angle is within a range of about 10 degrees to about 120 degrees. 
     
     
         19 . The zoning closed-die extruding method of  claim 11 , wherein the step (2) further comprises:
 finishing an inner surface of the sequentially and zonally extruded blank along the central hole of the blank using a finishing extrusion shaft so that the blank has an even wall thickness.   
     
     
         20 . The zoning closed-die extruding method of  claim 16 , wherein in the step (2), a pressing displacement is within a range of about 2 mm to about 2000 mm, and a pressing displacement every time in the step (3) is 0.01 times to 0.5 times as large as that in the step (2). 
     
     
         21 . (canceled) 
     
     
         22 . The zoning closed-die extruding method of  claim 10 , wherein a downward extrusion speed of the stamp-extruding head portion is within a range of about 5 mm/s to about 90 mm/s when the blank is made of a ferrous metal, or within a range of about 20 mm/s to about 300 mm/s when the blank is made of a nonferrous metal. 
     
     
         23 . The zoning closed-die extruding method of  claim 10 , wherein the closed female die is a prestressed extrusion die, and an inner diameter of the closed cavity of the prestressed extrusion die is greater than a maximum radial dimension of the extruding shaft portion and the stamp-extruding head portion. 
     
     
         24 . The zoning closed-die extruding method of  claim 10 , wherein the central hole with the predetermined depth is formed by closed upsetting, impressing and hot piercing the blank in the closed female die respectively, and the extruding shaft portion and the stamp-extruding head portion are integrally formed. 
     
     
         25 . (canceled) 
     
     
         26 . The zoning closed-die extruding method of  claim 10 , wherein the closed female die is a prestressed extrusion die, and an inner diameter of the closed cavity of the prestressed extrusion die is greater than a maximum radial dimension of the extruding shaft portion and the stamp-extruding head portion, or a cross section of the stamp-extruding head portion is of a rectangle shape, a long edge of the rectangle equals to a diameter of the extruding shaft portion, and a ratio of a short edge of the rectangle to the long edge thereof is within a range of about 0.05 to about 0.95, or a ratio of the cross-sectional area of the stamp-extruding head portion to the cross-sectional area of the extruding shaft portion is within a range of about 0.1 to about 0.9. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled)