Mitsubishi Heavy Industries Limited

Mitsubishi Jukogyo Kabushiki Kaisha

Yoshio Hashimoto

Takashi Ishide

Takashi Akaba

Yasumi Nagura

Masao Watanabe

Yukio Michishita

Tadashi Nagashima

Koji Okimura

Michisuke Nayama

Katsusuke Shimizu

Isao Shirasu

Shoichi Hamada

Shuhei Kuri

Takuya Kidera

Daijiro Fujie

Haruo Shirata

Seiichi Kawaguchi

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

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.

Laser beam machining head

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.

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,of a laser machining head,having optical systems,and,for focusing a laser light,oscillated by a laser oscillator,, a plasma machining head,is mounted coaxially with the optical systems,and,. The plasma machining head,is provided with electrode nozzles,and,connected to a plasma apparatus,and a working gas supply passage,connected to the electrode nozzles,and,so that the laser light,and a plasma arc,are irradiated towards a same machining position,of a machined part

Combined laser and plasma arc welding machine

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.

Hybrid welding apparatus

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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Takasago, Japan

Yoshio Hashimoto