| 摘要 |
PURPOSE:To make a device simple in construction and to perform efficiently a radially contracting work of a metallic pipe by radially contracting the metallic pipe by using rolls before contracting it by using dies. CONSTITUTION:A metallic tape 1 is supplied from a tape supplier 2, and is passed through a guiding device 3 to form it into a circular arc by passing it through forming rolls 4, 5. The tape 1 formed into the circular arc is successively passed through forming dies 8 to form it into an approximately circular shape. Next, the tape 1 is passed through forming rolls 9, 10, 11 to form it closer to the circular shape, and is taken up at the same time from the die 8 by forming rolls 9, 11 of driving type. The butting lines of the tape 1 are welded to each other by a welder 16 to form a metallic pipe 17 after bringing the butting lines into contact with each other by squeezing rolls 15. The obtained metallic pipe 17 is radially contracted by radially contracting rolls 19, 20, 21, 22 after cooling it by a cooler 18, and is successively fed into a radially contracting die 23 to contract further its diameter while taking it up by a take-up machine 24. |
