Kabushiki Kaisha Toshiba

Toshiba Engineering Corporation

3m Innovative Properties Company

Masaki Yoda

Yuji Sano

Satoshi Okada

Masahiro Yoshida

Yoshiaki Ono

Ryoichi Saeki

Mitsuaki Shimamura

Motohiko Kimura

Wataru Kono

Hideki Naito

Katsuhiko Sato

Hiroaki Igakura

Yoshio Hamamoto

Makoto Kondo

Shigeru Suzuki

Satoshi Yamamoto

Takahiro Miura

Naruhiko Mukai

Makoto Ochiai

Hidehiko Kuroda

Masataka Tamura

Yutaka Togasawa

Masahiro Takeuchi

Takuya Uehara

Michio Sato

Mikio Izumi

Hiromi Kato

Tatsuyuki Maekawa

Yoshifumi Sato

Itaru Chida

Hiroyuki Miyasaka

Akira Sudo

Kentaro Tsuchihashi

Tetsuro Aikawa

Yoshinobu Makino

Toru Onodera

Kenji Matsuzaki

Yoshinao Yamazaki

Fukashi Osakata

Akira Tsuyuki

Hisashi Hozumi

Katsunori Shiihara

Mitsuhiro Enomoto

Yuuichi Motora

Masakazu Abura

Muneyoshi Kikunaga

Yasumi Kitajima

Taiji Kobayashi

Yoshimi Tanaka

Nobuaki Ohno

Seishi Shima

Tatsuki Ogisu

Koki Okazaki

A heating laser beam is emitted to a cracked portion to remove moisture from the cracked portion, and subsequently, a welding laser beam is emitted to the cracked portion to heat and melt the cracked portion. The heating laser beam and the welding laser beam are emitted to an entire surface of the cylindrical body inside the reactor such as a stub tube penetrating through and fixed to a reactor bottom portion and a crack of the welded portion between the cylindrical body and the reactor bottom portion to thereby prevent a new crack from occurring and reactor water from leaking.

Reactor bottom repairing method

An improved laser shock hardening method and apparatus which can eliminate spattering of a liquid and waving of the liquid surface upon laser irradiation, and can stably irradiate a workpiece with a laser beam. In a laser shock hardening method for carrying out surface processing of a workpiece in contact with a liquid by irradiating through the liquid the surface of the workpiece with a pulsed laser beam intermittently emitted from a laser irradiation device, the disclosed method provides a solid transparent to the wavelength of the laser, serving as an entrance window to the liquid surface; allowing the liquid to be present in the light path of the laser beam between the solid and the surface of the workpiece; and allowing the laser beam to enter through the solid and irradiating through the liquid the surface of the workpiece with the laser beam.

Laser shock hardening apparatus

A nuclear reactor vibration surveillance system has a first ultrasonic transducer for transmission, an ultrasonic transmitter, a second ultrasonic transducer for reception, an ultrasonic receiver, a signal processor, and a display unit. The first ultrasonic transducer for transmission is arranged on the outer surface of a reactor pressure vessel and is configured to convert a transmission signal into an ultrasonic pulse signal and allow the ultrasonic pulse to be transmitted to a reactor internal component. The second ultrasonic transducer for reception is arranged on the outer surface of the reactor pressure vessel and is configured to receive a reflected ultrasonic pulse reflected by the reactor internal component and convert the received reflected ultrasonic pulse into a reception signal.

Nuclear reactor vibration surveillance system and its method

According to one embodiment, a laser welding apparatus has a laser irradiation head that is arranged in an outer frame and is divided inside into a light source side and an irradiation side by a partitioning member. The apparatus also has a gas jet nozzle that is formed so as to irradiate a portion to be welded with the laser light and jet the inert gas to the portion to be welded; and a welding wire feed pipe that sequentially feeds a welding wire. The apparatus also has a welding wire contact mechanism that includes a measuring means for measuring a distance between the extremity of the irradiation side and the extremity of the welding wire, and is formed so that the extremity of the welding wire is brought into contact with and pressed against the portion to be welded by an elastic member.

Laser welding apparatus

A method of sealing a surface crack in a member is provided includes steps of irradiating a region of the member at which the crack is produced with a heating laser beam so as to heat the region to a temperature lower than a melting point of the member, and then irradiating a region of the member at which the crack is produced with a welding laser beam subsequent to irradiation of the heating laser beam so as to heat the region to a temperature higher than or equal to the melting point of the member, thereby sealing an opening of the surface crack of the member.

Surface crack sealing method

There is provided an improved laser shock hardening method and apparatus which can eliminate spattering of a liquid and waving of the liquid surface upon laser irradiation, and can stably irradiate a workpiece with a laser beam. Thus, the present invention provides in a laser shock hardening method for carrying out surface processing of a workpiece in contact with a liquid by irradiating through the liquid the surface of the workpiece with a pulsed laser beam intermittently emitted from a laser irradiation device, the improvement comprising: providing a solid transparent to the wavelength of the laser, serving as an entrance window to the surface of the liquid; allowing the liquid to be present in the light path of the laser beam between the solid and the surface of the workpiece; and allowing the laser beam to enter through the solid and irradiating through the liquid the surface of the workpiece with the laser beam, thereby shock-hardening the surface of the workpiece.

Laser shock hardening method and apparatus

A laser maintenance apparatus including a laser system which includes an optical system for emitting, in a first irradiation condition, a generation laser beam for generating an ultrasonic wave in a portion of an object on which maintenance is to be performed, and including a laser source configured to generate and detect a detection laser beam which interacts with the ultrasonic wave generated by the laser light beam in the first condition. The laser maintenance apparatus also includes a light transmitting device for transmitting laser light emitted from the laser system, a laser irradiation device for irradiating laser light transmitted by the light transmitting device to the object portion, and a transporting/scanning mechanism for transporting the light transmitting device and the laser irradiation device to a portion near the object portion, and scanning over an arbitrary range at the object portion.

Laser-based maintenance apparatus

A laser emitting head for irradiating a portion to be machined with laser beams outputted from a laser unit () incorporates an emitting head body having a light guide member () in the head for guiding the laser beams; a light converging lens () for converging the laser beams transmitted from the light guide member in the head; a reflecting mirror () for irradiating the portion to be machined with the converged laser beams; mirror rotating means () for holding the reflecting mirror to be rotative around the optical axis of the laser beam; distance-adjustment means () for adjusting the relative distance between the reflecting mirror and the converging lens; and moving means () for moving the reflecting mirror and the converging lens such that the relative distance is maintained so that the light guide member in the head. The converging lens and the reflecting mirror can be introduced/discharged with respect to a portion to be machined and formed in a narrow gap in an incore structure. As a result, a preventive-maintenance/repair operation using laser beams and arranged to be performed in a narrow gap in the incore structure can safely and efficiently be performed.

Laser emission head, laser beam transmission device, laser beam transmission device adjustment method and preventive maintenance/repair device of structure in nuclear reactor

A laser transmission system for transmitting laser beam to an optical fiber comprises a pulse laser oscillator unit, a beam guide unit having an optical condensing unit for condensing a pulse laser beam radiated from the pulse laser oscillator unit, an optical fiber unit for transmitting the pulse laser beam condensed by the optical fiber beam guide unit, and a device for reducing a coherence of the pulse laser beam provided for at least one of the pulse laser oscillator unit, the beam guide unit and the optical fiber unit. This coherence reducing device is for making substantially uniform distribution of laser beams at a beam entrance portion of the optical fiber unit and preventing the laser beams from focussing or converging on one point in the optical fiber unit.

Laser transmission system

The present invention provides an underwater maintenance and repair technology of including a laser oscillator for generating a laser beam and a working head movably attached to the vicinity of a working target portion in the underwater and adapted to scan the laser beam to the working target portion, and further, independently fixing the working head to the vicinity of the working target portion, jointing an optical fiber cable to the working head by using a joint mechanism through a remote control operation, guiding a laser beam emitted from a laser oscillator via the optical fiber cable, and irradiating the laser beam from the working head to a surface of the working target portion while scanning it so as to achieve surface modification, surface working and decontamination.

Underwater maintenance repair device and method

A laser maintaining and repairing apparatus including a laser oscillator 7, beam guiding apparatus 8 connected to guide a laser beam of the laser oscillator 7, and emitting head 12 for converging the laser beam from the beam guiding apparatus 8 and emitting the beam to a portion to be processed. The beam guiding apparatus 8 includes liquid-tight tubular beam guiding members 9a to 9h. The beam guiding members 9a to 9h are provided with reflecting members 13a, 13b and at least one of mechanisms 10a, 10b and 11a, 11b for providing horizontal turning, horizontal extending, vertical turning and vertical extending operations at the beam guiding members 9a to 9h. With the laser maintaining and repairing apparatus of the noted structure, a laser beam of high energy density can be utilized and processing by the laser beam can be facilitated or the applying range can be increased.

Laser maintaining and repairing apparatus

An optical-modulation-type sensor comprises an input condenser lens for collecting light from a light source, a polarizer for linearly polarizing the light from the input condenser lens, a light-transmissive piezo-oscillator which is provided with an oscillator circuit and to which the linearly polarized light is introduced from the polarizer, an analyzer for linearly polarizing the light from the piezo-oscillator, and an output condenser lens for converging the linearly polarized light from the analyzer. A process instrumentation apparatus using the sensor of the structure described above further comprises an optical fiber for transmitting the light from the light source to the optical-modulation-type sensor, a photoelectric converter operatively connected to an output side of the optical-modulation-type sensor for converting to an electrical signal the transmitted light which is intensity modulated with the oscillation frequency of the piezo-oscillator, and a signal processing unit for acquiring a process quantity based on the frequency of an output signal from the photoelectric converter.

Optical-modulation-type sensor and process instrumentation apparatus

Growing community of inventors

Yokohama, Japan

Masaki Yoda