| 摘要 |
PURPOSE:Seamless pipe is economically and efficiently provided by coordinate work of rolling rolls and a mandrel. The rolling rolls have elliptic cross section calibers and a mandrel has a specified elliptic form. The mandrel is also properly lubricated. CONSTITUTION:The mandrel 10 has pipe rolling functioning contacts portion 11, 12, 13 where the mandrel has shapes such that the gap between the mandrel 10 and the opposing caliber cross sections maintain about constant in peripheral direction, or, where the mandrel and the rolls are nearly parallel. Accordingly, the caliber elliptic mahor/minor axiw ratio is larger than the at-contact mandrel elliptic major/ minor axis ratio. When rolling, the thrust block 14 advances in the direction of rolls, and the mandrel is positioned by inserting it into the hole of pipe matrial P. Then, the material P is moved by the feed rolls 15, 15' to be rolled. Liquid lubricator is jetted from near the at-contact mandrel to fill the gap between the mandrel and the pipe. |
