REDUCED THICKNESS ROLLING DEVICE FOR PIPE END IN INSTALLATION FOR PRODUCING SEAMLESS STEEL PIPE

摘要

PURPOSE:To provide a titled reduced thickness rolling device which suppresses flaring with the thickness reduction in the outside peripheral part at the end of a hollow blank pipe by disposing guide shoes which restrain the outside peripheral part at the end of said pipe to a mandrel side in the position space from rolling rolls under revolution and rotation in the circumferential direction of the hollow blank pipe to be subjected to reduced thickness rolling. CONSTITUTION:Rolling rolls 14 are pressed, in the state of revolution and rotation, to the outside peripheral part at the end of a hollow blank pipe 6. The revolving and rotating speeds of the rolls 14 are relatively adjusted to prevent the rolls 14 from exerting torque on the end of the pipe 6. The rolls 14 reduce the thickness at the end of the pipe 6 at the preset ratio of thickness reduction. The mandrel 13 is projected during this time so as not to move relatively with the pipe 6 and is kept inserted in the rolls 14 during the time when the rolls 14 roll the pipe 6 to reduce its thickness. The outside peripheral part at the end of the pipe 6, which is not rolled down, is restrained and held to the mandrel 13 side by means of guide shoes 42 while the pipe is under reduced thickness rolling by the rolls 14, whereby the flaring in the outside peripheral part at the end of said pipe is suppressed.