Ihi Corporation

Ihi Infrastructure Systems Co., Ltd.

Daiki Okita

Naoyuki Matsumoto

Koutarou Inose

Junko Yamada

Hiroto Yamaoka

Akira Katou

Yoshihiko Nakamura

Kenshiro Kimura

Shota Nakanishi

Shinya Osawa

Irradiation with a laser beam is performed along a welding bead, while the laser beam is aimed, as an irradiation point of the laser beam, at a contact point between a deck plate and a U-rib that is contained in a non-welded portion of a root part, from a side of the welding bead of the root part. Thereby, it is possible to remove a crack beginning at the non-welded portion of the root part generated at a joining portion between the deck plate and the U-rib of a steel floor slab, by the irradiation with the laser beam.

Repairing laser welding method and repairing laser welding device

A laser welding repair device includes a laser oscillator, a laser head that condenses laser light from the laser oscillator to irradiate a repair portion, a temperature sensor that detects a temperature distribution of a steel material irradiated with the laser light, and a control unit. The control unit sets a spot diameter of the laser light to be less than 3 mm, moves the laser head and enlarges a heat input area to check for a crack in the heat input area, the heat input area being formed by irradiating the steel material with the laser light, and controls the laser head to irradiate a region where a temperature detected by the temperature sensor is equal to or less than a mechanical melting temperature of the steel material. Where a welding is performed in a flat position, the crack can be easily and reliably erased without causing burn through.

Laser welding method for repair, and laser welding repair device

A crack repair method includes a build-up welding step of performing build-up welding on a portion of an existing steel structure where a crack is generated while feeding a filler wire, and a laser beam piercing welding step of performing piercing welding using a laser beam on a filler material build-up portion caused by the build-up welding in the build-up welding step and the crack. The crack can be melted and repaired without lowering a toughness value regardless of an operation condition.

Crack repair method for existing steel structure

Provided is a crack repair method of melting and eliminating a crack generated in a steel material, the method including holding a tab plate in surface contact with the steel material in which the crack is generated, thereafter continuously irradiating the tab plate to a first end portion of the crack in the steel material with a laser beam, and subsequently continuously irradiating the crack with the laser beam along the crack to a second end portion of the crack to melt and eliminate the crack. Consequently, when eliminating the crack generated in a constituent member of an existing structure or a constituent member such as a machine component, the crack can be eliminated without forming a through hole in the constituent member.

Crack repair method

A metal-resin joining method of joining a metal member to a composite material member including a fiber reinforced plastic composite material includes an applying step of applying a first adhesive that is a thermosetting adhesive to a first region between the metal member and the composite material member, and applying a second adhesive that is a thermosetting adhesive to a second region between the metal member and the composite material member, a provisional bonding step of irradiating a first irradiation region of the metal member opposed to the first region with a laser light, and heating and curing the first adhesive to provisionally bond the metal member and the composite material member together, and a main bonding step of curing the second adhesive after the provisional bonding step to bond the metal member and the composite material member together.

Growing community of inventors

Tokyo, Japan

Daiki Okita