A METHOD OF PRODUCING A UNITARY PIPE HAVING A COMBINATION OF SQUARE AND CIRCULAR CROSS SECTIONS

摘要

A method of producing a unitary pipe having a combination of square and circular cross sections comprising the steps of securely clamping a workpiece (10) or a pipe having a square cross section to a workpiece grip of a lathe machine; spinning the securely clamped workpiece (10) according to a predetermined spinning speed by operating the lathe machine; heating up a predetermined portion of the workpiece (10) with a heating torch (12); extinguishing the heating torch (12) once the required maximum temperature is reached; pressing a roller having a flat rim (13) against the heated portion of the workpiece (10) to gradually transform its square cross section into a circular cross section; and pressing the transformed portion with a roller having a round rim (14) when the workpiece (10) is at a predetermined lower temperature to produce a rounded common spot of the square cross section and the transformed circular cross section.