Mitsubishi Heavy Industries Limited

Mitsubishi Jukogyo Kabushiki Kaisha

Shinsei Corporation

Takashi Akaba

Takashi Ishide

Shuho Tsubota

Tadashi Nagashima

Yoshio Hashimoto

Noriaki Sugimoto

Masao Watanabe

Kenji Nishikawa

Isao Shirasu

Takahiro Ohta

Yasumi Nagura

Hironori Onitsuka

Susumu Miki

Shoji Kushimoto

Masahiro Kato

Yukio Michishita

Takahiro Ota

Kazuhiko Kamo

Koji Okimura

Toshiiku Sashida

Kenichi Kawanishi

Shoichi Hamada

Shuhei Kuri

Kyoichi Yoshioka

Yoshimasa Tsukamoto

Yuichi Ohtani

Michisuke Nayama

Katsusuke Shimizu

Seiichi Kawaguchi

Takuya Kidera

Osamu Noda

Naoaki Ikeda

Jyunichi Mizui

Syuhou Tsubota

Daijiro Fujie

Yoshiyuki Hemmi

Aims are to provide a tubular-body residual-stress improving apparatus and an adjustment method thereof capable of adjusting irradiation position with favorable reproducibility, even when an optical fiber is eccentric. In the tubular-body residual-stress improving apparatus, an optical control unit () includes a rotational hold mechanism () for holding an optical fiber () in a manner that the optical fiber () is rotatable in a circumferential direction of the optical fiber (), and, if a position of an intensity peak of the laser beam from the optical fiber () in an axial direction of the tubular body () is offset from the center of an irradiation profile, a position at which the optical fiber () is held in the circumferential direction is adjusted by the rotational hold mechanism () so as to eliminate the offset or to minimize an influence of the offset.

Apparatus for improving residual stress in tubular body and adjustment method of the same

An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When an outer-circumferential surface of a welded portion of a cylindrical tubular body () is irradiated with a laser beam that circles around an outer circumference of the tubular body (), a heating width W in a circumferential direction heated by the laser-beam irradiation and a laser-beam moving speed V in the circumferential direction are set so that a stress in the circumferential direction in an inner surface of the tubular body () produced by the heating with the laser beam is at least larger than a yielding stress of a material that the tubular body () is made of.

Method for improving residual stress in tubular body and apparatus for improving residual stress in tubular body

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 () is irradiated and heated with a laser beam emitted from a laser head () to remove residual stress. At this time, a rotating travel cart () travels along a ring rail () to adjust the position of the laser head () in a &#x3b8;-direction, a vertical slide () slides to adjust the position of the laser head () in a Z-direction, a radial slide () slides to adjust the position of the laser head () in an L-direction, an arcuate piece slide () slides along an arcuate piece to adjust the &#x3b1;-direction of the laser head (), a laser head support portion () turns to adjust the &#x3b2;-direction of the laser head (), and oscillation adjusts the position of the laser head () in a &#x3b3;-direction.

Apparatus for improving residual stress of piping technical field

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 is provided. The apparatus has a laser head portion, and circumferential direction moving mechanism composed of a ring rail and a rotational travel bogie. Further, the apparatus may adjust the reflection direction of laser light so that the laser light reflected by the outer peripheral surface of the piping does not return to the laser head, and adjust the delivery direction of the laser light so that the outer peripheral surface of the bending pipe portion located forwardly, in the pipe axis direction, of the laser head is irradiated with the laser light.

Residual stress improving apparatus for piping technical field

A nonlinear optical crystal device, a wavelength conversion element, is surrounded with a heat sink having cooling fins. Cartridge heaters for uniformly heating the nonlinear optical crystal device are arranged in the heat sink, and the temperature of the cartridge heater is regulated by a heater controller. Laser light is input into the nonlinear optical crystal device, and delivered therefrom after its wavelength is converted into a shortened wavelength. When the repetition frequency of laser light is high, heating by the heaters is stopped, and cooling is effected with the heat sink. When the repetition frequency of laser light is low, heating by the heaters is carried out to maintain the temperature of the nonlinear optical crystal device to be a temperature at which a conversion efficiency is satisfactory.

Laser wavelength converter

Laser light emitted from an LD apparatus is concentrated and applied onto a laser light path region A of a slab-shaped YAG crystal and the neighborhood thereof with the use of a concave lens and a pair of reflecting mirrors, a duct lens, or a plurality of cylindrical lenses, whereby a concentrated applied light intensity distribution in the side surface width direction (y-axis direction) of the slab-shaped YAG crystal is formed as a double-peak distribution having maximum values P and P at opposite end portions A and A of the laser light path region of the slab-shaped YAG crystal or in the neighborhoods thereof.

Solid state laser apparatus

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.

Laser machining apparatus

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. The head comprises a collimating lens array, a first reflecting mirror for dividing laser light into a first divisional laser beam and a second divisional laser beam, a second reflecting mirror for further reflecting the first divisional laser beam to form a space portion between both divisional laser beams, a focusing lens array for focusing both divisional laser beams onto a portion to be welded, and a GMA electrode disposed in the space portion coaxially with the laser beams; or comprises a collimating lens array, a first reflecting mirror for reflecting part of laser light to form a space portion in a body of the laser light, a second reflecting mirror for further reflecting the part of the laser light, a focusing lens array for focusing the body of the laser light and the part of the laser light onto a portion to be welded, and a GMA electrode disposed in the space portion coaxially with the body of the laser light.

Laser beam machining head and laser beam machining apparatus having same

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.

Laser beam machining head

A small-sized ultrasonic motor can produce a high torque and a stable turning force. The ultrasonic motor has: a cylindrical casing, a hollow output shaft extending coaxially through the cylindrical casing supported rotatably by the casing a ring-like stator fixedly mounted on the inner surface of the cylindrical casing having piezoelectric elements fixed on the back surface thereof, a ring-like rotor mounted on the hollow output shaft and facing the front surface of the stator, and springs for pushing the rotor toward the stator. Also disclosed is a laser beam welding apparatus for welding the inner circumferential surface of a tube by using the ultrasonic motor.

Ultrasonic motor and laser beam welding apparatus using the same

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. Also, an improved laser beam welding apparatus for an inner circumferential surface of a tube is provided by employing the aforementioned improved reflection mirror as a reflecting mirror in an optical condensing system included in a laser beam welding apparatus for an inner circumferential surface of a tube, which apparatus comprises a flexible tube including an optical fiber extended therethrough for transmitting a welding laser beam, said flexible tube being insertable into a work tube, a position detector for detecting a relative position of the flexible tube with respect to the work tube and fixing means of internally expansible type for fixing the flexible tube within the work tube, respectively provided at the front end portion of the flexible tube, a rotary cylinder rotatably supported from the flexible tube, guide support means mounted to the rotary cylinder in a relatively rotatable manner and being able to be held in contact with the inner wall surface of the work tube for holding the rotary cylinder concentrically with the work tube, rotary drive means having its output shaft disposed coaxially with said rotary cylinder for rotationally driving the rotary cylinder, an optical condensing system disposed within said rotary cylinder for leading the welding laser beam emanating from the front end of the optical fiber to the inner wall surface of the work tube in a condensed state, gas scavenging means for discharging metal vapor produced upon welding of the work tube, and gas cooling means for cooling the optical condensing system.

Reflecting mirror for a laser beam and laser beam welding apparatus,

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Kobe, Japan

Takashi Akaba