JPS5741808A - Rolling method for metallic pipe - Google Patents

Abstract

PURPOSE:To send a withdrawn mandrel at once back to the feed-in side of an elongator through another route, and to improve the productivity and quality, by installing a mandrel returning device in the separate route, other than a mandrel recovery device and a metallic pipe recovery device arranged on the run-out side of the elongator. CONSTITUTION:A blank pipe HS fitting a mandrel MB is transferred from a charging table 83 onto a guide table 9 arranged on the upstream side of an elongator 1. A clamp 91 grasps the rear end of the mandrel MB, and then, the blank pipe HS together with the mandrel MB are fed toward the elongator 1. When the rolling stands 11-16 start the rolling work, the guide table 9 advances the mandrel MB in order to elongate the blank pipe HS into a pipe SP in a prescribed size, which is then extracted by an extractor 2 and is shifted forward on a discharging table 3. Then the mandrel MB is withdrawn from the pipe SP, the clamp 91 is released from grasping the mandrel MB which is then discharged into a prescribed distance from the pipe SP. The movements of the pipe SP and the mandrel MB are stopped by a pipe recovery device 5 and a mandrel recovery device 4, the mandrel MB is transferred onto a conveyer 6, and is cnveyed to the upstream side of the elongator 1; the mandrel MB is then cooled and is applied with a lubricant, is conveyed to a charging table 82, and is again assigned to the pipe manufacturing process.