Abstract: A residual stress improving apparatus for piping, which can heat an outer peripheral surface of piping to reduce (including eliminate) the residual stress of the piping, whose apparatus configuration is relatively compact, and which can also heat the outer peripheral surface of a bending pipe portion, is provided. For this purpose, the apparatus has a laser head portion 6, and circumferential direction moving means composed of a ring rail 3 and a rotational travel bogie 5.

Abstract: A weld zone of T-piping and its neighborhood are efficiently laser-heated to remove residual stress. For this purpose, the weld zone of a T-piping (50) is irradiated and heated with a laser beam emitted from a laser head (10) to remove residual stress. At this time, a rotating travel cart (3) travels along a ring rail (2) to adjust the position of the laser head (10) in a ?-direction, a vertical slide (4) slides to adjust the position of the laser head (10) in a Z-direction, a radial slide (5) slides to adjust the position of the laser head (10) in an L-direction, an arcuate piece slide (7) slides along an arcuate piece to adjust the ?-direction of the laser head (10), a laser head support portion (9) turns to adjust the ?-direction of the laser head (10), and oscillation adjusts the position of the laser head (10) in a ?-direction.

Abstract: Control is exercised such that an arc discharge from a GMA electrode is performed after or simultaneously with start of oscillation of laser light from a laser oscillator, and oscillation of the laser light from the laser oscillator is stopped after or simultaneously with termination of the arc discharge from the GMA electrode. A coaxial laser beam machining head is configured such that the GMA electrode is disposed in a space portion between a first divisional laser beam and a second divisional laser beam, which have been formed by division by first and second reflecting mirrors, coaxially with the laser beams. Alternatively, the coaxial laser beam machining head is configured such that the GMA electrode is disposed in a space portion, which has been formed in a body of laser light by withdrawing part of the laser light outwardly with the use of first and second reflecting mirrors, coaxially with the body of the laser light.

Abstract: A coaxial laser beam machining head, and a laser beam machining apparatus having it are provided. The head is small in size, free from the risk of damaging optical instruments, and inexpensive.

Abstract: In a welding system for performing butt welding which comprises butting the end surfaces of steel plates, materials to be welded, placed on the upper surface of a table of a welding stage and welding the end surfaces together, a welding head is a laser/arc combined welding head for simultaneously performing laser light irradiation and arc discharge of the materials 38 to be welded, thereby welding the materials to be welded, and the position of an arc electrode 40 in an up-and-down direction relative to the materials 38 to be welded, the position of the arc electrode in a direction perpendicular to the direction of the optical axis of laser light 32 applied to the materials 38 to be welded, and the inclination angle of the arc electrode relative to the optical axis of the laser light 32 can be adjusted.

Abstract: In a welding system for performing butt welding which comprises butting the end surfaces of steel plates, materials to be welded, placed on the upper surface of a table of a welding stage and welding the end surfaces together,

Abstract: Control is exercised such that an arc discharge from a GMA electrode is performed after or simultaneously with start of oscillation of laser light from a laser oscillator, and oscillation of the laser light from the laser oscillator is stopped after or simultaneously with termination of the arc discharge from the GMA electrode. A coaxial laser beam machining head is configured such that the GMA electrode is disposed in a space portion between a first divisional laser beam and a second divisional laser beam, which have been formed by division by first and second reflecting mirrors, coaxially with the laser beams. Alternatively, the coaxial laser beam machining head is configured such that the GMA electrode is disposed in a space portion, which has been formed in a body of laser light by withdrawing part of the laser light outwardly with the use of first and second reflecting mirrors, coaxially with the body of the laser light.

Abstract: A laser beam machining head includes a dividing optical system for dividing laser light into two separate laser beams, and providing spacing therebetween; a condensing optical system for condensing the separate laser beams into condensed laser light, and projecting it onto a cutting site of an object to be cut; and an inner assist gas nozzle placed between the separate laser beams, a width of an opening of a tip portion of the inner assist gas nozzle being nearly equal to a cutting width. Or the tip opening of the inner assist gas nozzle is slender; or its tip side is inclined, and the angle of inclination is variable; or the relative positions of the inner assist gas nozzle and a workpiece, or the relative positions of the focal position of the condensing optical system and the workpiece are variable independently; or an outer assist gas nozzle surrounding the separate laser beams is provided.

Abstract: A coaxial laser beam machining head, and a laser beam machining apparatus having it are provided. The head is small in size, free from the risk of damaging optical instruments, and inexpensive.

Abstract: A laser beam machining head includes a dividing optical system for dividing laser light into two separate laser beams, and providing spacing therebetween; a condensing optical system for condensing the separate laser beams into condensed laser light, and projecting it onto a cutting site of an object to be cut; and an inner assist gas nozzle placed between the separate laser beams, a width of an opening of a tip portion of the inner assist gas nozzle being nearly equal to a cutting width. Or the tip opening of the inner assist gas nozzle is slender; or its tip side is inclined, and the angle of inclination is variable; or the relative positions of the inner assist gas nozzle and a workpiece, or the relative positions of the focal position of the condensing optical system and the workpiece are variable independently; or an outer assist gas nozzle surrounding the separate laser beams is provided.

Abstract: In a laser beam machine head, when a filler wire and an optical axis of a laser beam are arranged coaxially, a convex roof mirror and a concave roof mirror are combined to divide the laser beam into two separate laser beams to that no laser beam is projected onto a filler wire feed pipe. Furthermore, the filler wire is fed from outside the laser beams to a condensing position via a filler wire guide in the spacing between the separate laser beams, or an electrode supported by a water flow pipe or an electrode holding pipe is brought close to the condensing position.

Abstract: Focused laser light and plasma arc are coaxially disposed to provide a laser machining head which performs a high precision and efficient machining, by reinforcing laser light with plasma arc to form a versatile heat source. For this purpose, in a tip part 6 of a laser machining head 10 having optical systems 4 and 5 for focusing a laser light 11 oscillated by a laser oscillator 1, a plasma machining head 20 is mounted coaxially with the optical systems 4 and 5. The plasma machining head 20 is provided with electrode nozzles 24 and 25 connected to a plasma apparatus 15 and a working gas supply passage 19 connected to the electrode nozzles 24 and 25 so that the laser light 11 and a plasma arc 28 are irradiated towards a same machining position 14 of a machined part 13.

Abstract: A hybrid welding apparatus for subjecting a base metal to gas-shielded arc welding and laser welding comprises a laser generator for emitting a laser beam and a condenser optical system for condensing the laser beam to laser weld the base metal. The condenser optical system includes a plurality of lenses, each having a hole portion in the center thereof. A tubular supply holder for supplying a welding wire is passed through these respective hole portions of the lenses and located substantially coaxially with the axis of the condenser optical system. The laser beam and welding wire to be applied to the base metal are arranged coaxially, so that laser-welding and arc-shielded welding can be simultaneously performed with a wide angle between the welding head and a bevel of the base metal, thereby deepening penetration of the weld at an increased welding speed.

Abstract: In a method for monitoring laser beam welding, a sequential signal representing a laser oscillating wave form is received, light of a predetermined wavelength in the light emitted from the weld zone is received, and the two signals thus received are processed to determine the minimum intensity of the light of the predetermined wavelength and thereby accurately deduce welding beam input and penetration of welding. An apparatus used in practicing the monitoring method includes a monitoring optical fiber for receiving and transmitting the light emitted from a weld being made on a workpiece, an interference filter for selectively passing light of a predetermined wavelength, and a processing device for determining an intensity of the light of the predetermined wavelength.

Abstract: The known reflecting mirror for a laser beam conisting of a mirror base member and a high-reflectivity metal coating layer formed on the mirror base member for reflecting a laser beam, is improved so as to maintain a high mirror reflectivity without necessitating a cooling facility. The improvements reside in that a coating layer having a small diffusion coefficient is provided on the back surface side of the high-reflectivity metal coating layer, and/or in that at least one layer of dielectric coating layer or layers are provided on the surface of the high reflectivity metal coating layer.

Abstract: An improved laser beam welding apparatus for an inner circumferential surface of a tube is disclosed herein, which apparatus comprises an elongated flexible tube containing an optical fiber extended along the length thereof so as to transmit a laser beam, position detecting means disposed in the vicinity of the top end of the flexible tube to determine relative positioning thereof with respect to a work tube in which the flexible tube is inserted, holding means provided with an expander and disposed adjacent to the position detecting means for holding the tip end of the flexible tube in the work tube, rotary drive means disposed closer to the tip end of the flexible tube than the holding means, a rotary cylinder connected to the rotary drive means to be rotated with respect to the flexible tube, guide means mounted on the rotary cylinder in a relatively rotatable manner with respect to the rotary cylinder and held in contact with the inner surface of the work tube for supporting the rotary cylinder in a conce