Patent ID: 9636727
Date: 2017-05-02
CPC Classifications: B21C

Claim:
1. A device for drawing a tubular workpiece, comprising: a drawing die for processing an outer surface of the tubular workpiece; and a drawing plug arranged in a hollow portion of the workpiece to process an inner surface of the workpiece, wherein the drawing die includes: a first curved surface section including a workpiece separation point at which the workpiece is detached from the first curved surface section while being reduced in diameter; a transition section downstream of the workpiece separation point of the first curved surface section, the first curved surface section and the transition section being configured such that the workpiece is not in contact with the transition section and the workpiece is further reduced in diameter while the workpiece is in the transition section; a die bearing section arranged radially inward of and downstream of the workpiece separation point of the first curved surface section; and a guide section including a second curved surface section smoothly continuing to an upstream end of the die bearing section and configured to again come into contact with the workpiece detached from the first curved surface section to guide the workpiece to the die bearing section while reducing a diameter of the workpiece, wherein the drawing plug has a plug bearing section arranged at a position corresponding to the die bearing section and shorter than the die bearing section, and wherein the first curved surface section, the transition section, the guide section, and the die bearing section of the drawing die are integrally formed.