| 摘要 |
PURPOSE:To make a rolling cycle short and to prevent the inner surface of a seamless pipe from producing flaws, by setting optionally the positions of locking and releasing a mandrel, in a titled installation for performing a semifloating method. CONSTITUTION:A hollow pipe stock HS inserted with a mandrel MB, is mounted between a pair of endless chains 3 arranged oppositely and circulated together. At that time, a locking fittings 4 is provided to a pair of the chains 3 movably in one body with them, to lock the mandrel MB at the end of the upstream side in the rolling direction thereof in a state of opening the upper surface of fitment 4, and the pipe HS is fed to the mendrel MB to roll it while controlling the movement of fittings 4. A pair of rails 5 are installed parallelly to each other and oppositely to the chains 3, and are made movable in the rolling direction, and are equipped with a slant surface 5c at the end parts of the downstream side of them to release the locking of mandrel MB by slanting the fittings 4 to the downstream side. By said mechanism; in case of performing the rolling mode of an minimum inserting length of mandrel, the locking of mandrel MB can be released directly after finishing the rolling regardless of the length of pipe HS, to achieve the object. |
