| 摘要 |
PURPOSE:To quickly and smoothly draw a mandrel online by gripping the end of a metallic pipe after rolling by frictional force in the rear stage of a rolling device, relatively displacing the mandrel and the metallic pipe in axial opposite directions and drawing the mandrel. CONSTITUTION:The metallic pipe 27 is rolled in the state in which the axial speed of the mandrel 26 fitted into a hollow part is controlled to a prescribed value. A mandrel fixing device 26 fixes the rear end of the mandrel 26 when the pipe 27 stops by clearing the device 25; at the same time, a carriage 28 starts moving and a restraining device 29 advances into the front end of the pipe 27, thus restraining the pipe 27 by the frictional force. The carriage 28 retreats and draws the pipe 27 from the mandrel 26, then the device 29 releases the restrain thereof. The carriage 28 retreats further while the pipe 27 is made to remain. The mandrel is thereby quickly and smoothly drawn online.
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