METHOD FOR MANUFACTURING UNEVEN THICKNESS METALLIC TUBE AND DIE FOR WORKING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an uneven thickness metallic tube adequate as a weight reduction workpiece of machine parts, such as a rack bar of an automobile. SOLUTION: A method is for manufacturing the uneven thickness metallic tube in which the center of the external diameter is deviated from the center of the inner diameter from metallic tube stock by cold drawing using a die is characterized in that the metallic tube stock is a metallic tube formed at a uniform wall thickness in a circumferential direction and that the uneven thickness is formed by pushing the metallic tube stock into a die in which the inlet side central axis and outlet side central axis of a drawing section for drawing the stock are deviated. The die for working used for the same is provided in which the inlet side central axis and outlet side central axis of the drawing section are deviated. In the above manufacturing method, as the metallic tube stock, metallic tube stock formed with uneven thickness by cold drawing using a die can be used and the prescribed external diameter and thickness can be obtained by repeating the cold drawing a required number of times. COPYRIGHT: (C)2004,JPO