RESIDUAL STRESS IMPROVING DEVICE OF TUBULAR BODY

摘要

An aim is to provide a tubular-body residual-stress improving apparatus capable of reducing irradiation on unnecessary areas by controlling the optical paths of laser beams. In the tubular-body residual-stress improving apparatus, an optical control unit (5C) includes one pair of mirrors (21, 22) being disposed at a final stage of an optical system for a plurality of laser beams (P1-Pn) to be sharable and disposed in such a way that the mirrors are placed respectively at both sides, in the circumferential direction of the tubular body (2), of a final optical path of the laser beams to the tubular body (2), and another pair of mirrors (23, 24) being disposed at final stage of the optical system for the laser beams at both ends and disposed in such a way that the mirrors are placed respectively at both sides, in an axial direction of the tubular body (2), of final optical paths of the laser beams at both ends to the tubular body (2). Two pairs of mirrors (21-24) reflect inwards a skirting portion of the corresponding laser beam in the circumferential and axial direction of the tubular body (2) so as to irradiate the tubular body (2) with the laser beams.