Tube with high dimensional accuracy, and method and device for manufacturing the tube

A highly efficient method for manufacturing a high dimensional accuracy pipe, comprising a push-to-pass process which includes:

• pushing at least one metal pipe in a hole provided in a die while a plug is being charged in the metal pipe;
• and
• allowing the metal pipe to pass through the hole;
• wherein when at least one of a deviation of the outside diameter, a deviation of the inside diameter, and a deviation of the thickness in the circumferential direction of each of the pipes is improved by the push-to-pass process, the pipes are continuously fed in the die using a pipe feeding mechanism provided at an inlet side of the die while the plug is being charged in each of the pipes and is being floated.

A method for manufacturing a high dimensional accuracy pipe having superior surface quality, comprising a push-to-pass process which includes:

• pushing at least one metal pipe in a hole provided in a die while a plug is being charged in the metal pipe;
• allowing the metal pipe to pass through the hole;
• and
• applying a lubricant film to at least one of an interior and an exterior surface of the pine;
• and
• wherein after at least one of the interior and exterior surface of the pipe is provided with a lubricant film, the plug is charged in the pipe, and the push-to-pass process is performed using the die.

A stable method for manufacturing a high dimensional accuracy pipe, comprising a push-to-pass process which includes:

• pushing at least one metal pipe in a hole provided in a die while a plug is being charged in the metal pipe;
• and
• allowing the metal pipe to pass through the hole;
• wherein:
• while the plug is being charged in the pipe, the pipe is pushed in the hole provided in the die and is then allowed to pass therethrough,
• the plug has an angle of 5 to 40° which is formed between the surface of a diameter reducing portion and a processing central axis and a length of 5 to 100 mm of the diameter reducing portion, and
• the die has an angle of 5 to 40° which is formed between the interior surface of the hole at an inlet side and the processing central axis.

A manufacturing apparatus for manufacturing a high dimensional accuracy pipe, comprising:

• a plug capable of being in contact with an entire inner circumference of at least one metal pipe,
• at least one die having a hole capable of being in contact with an entire outer circumference of the metal pipe, and
• a pipe pushing device which pushes the metal pipe,
• wherein while the plug is being charged in the metal pipe, the metal pipe is pushed in the hole in the die and is then allowed to pass therethrough, whereby a push-to-pass process is performed.