COLD EXTRUSION PROCESS FOR INTERNAL HELICAL GEAR

摘要

PURPOSE: To form internal teeth for a ring gear without deposit and attrition of metal by moving an annular punch between a die ring and a mandrel and partially extruding a workpiece through a die ring. CONSTITUTION: With a workpiece 42 inserted into the pilot part 16 of a mandrel, a die ring 32 is moved to an upper position by a hydraulic cylinder rod 34. A punch 26 presses the advancing workpiece 42 against a workpiece 30, extruding the latter through teeth 20. The die ring 32 starts moving with the workpiece 30, which is completely extruded, while the workpiece 42 is partially extruded. In the next step, since the extruded workpiece falls off the teeth, the die ring 32 is moved upward by a hydraulic piston rod together with the partially extruded workpiece. The continuous motion of this punch ring enables another workpiece to be loaded, making this cycle repeated.