APPARATUS AND METHOD FOR CHANGING PIERCER ROLL OF VERTICAL PIERCING MILL

摘要

An apparatus and a method for changing a piercer roll of a vertical piercing mill, capable of automating the change operation of a piercer roll and coping with the requirement for a small-lot, multi-product production of seamless steel pipes having small to large diameters. The apparatus comprises a travelling truck capable of travelling while loading upper and lower cradles and a cradle shifter provided to the travelling truck, for transferring the upper and lower cradles to the inside of a main body of a vertical piercing mill at the travelling end position of the truck. The cradle shifter includes a spacer clamper for holding a spacer and adjusting its height and means for restraining the lower cradle. Therefore, the piercer roll change operation can be automated by a simple construction and the time for the change operation can be reduced without decreasing the work efficiency.