METHOD FOR MACHINING END PART OF STEEL PIPE

摘要

A method for machining the end part of a steel pipe in which chips produced through machining can be prevented from growing long without lowering the machining efficiency. Under a state where a rotary machine is driven to turn a tip (34) fixed to a tool along a path copying the outer end part of a steel pipe (16), the body of the apparatus is moved to approach the end part of the steel pipe (16) and the outer end part of the steel pipe (16) is cut by means of the turning tip (34). When the body of the apparatus advances by the feed length of intermittent cutting operation, the body (14) retreats by a preset temporary retreat length from the end part of the steel pipe and the cutting operation is interrupted when the tip (34) separates from the cutting face. The end part of the steel pipe is subjected to a specified amount of chamfering and surface machining by repeating a process where the body of the apparatus is advanced after being stopped for a specified time at the retreat position, and retreated from the end part of the steel pipe after it is further advanced by the feed length of intermittent cutting operation from the position of interrupting the cutting operation.