A laser welding method of the present disclosure includes the step of irradiating a workpiece with a laser beam in a helical shape along a weld part of the workpiece. The helical shape is a combination of a circular trajectory in which a laser beam is moved circularly, and a movement trajectory in which the laser beam is moved in a proceeding direction along the weld part. Furthermore, first energy of the laser beam moving so as to have a component of the proceeding direction in the circular trajectory is larger than second energy of the laser beam moving so as to have a component of an opposite direction to the proceeding direction in the circular trajectory.

Laser welding method

A vehicle body lower section structure comprises a rocker that extends in a vehicle body front-rear direction at a vehicle width direction outside of a floor panel; a first cross member that extends in the vehicle width direction at a lower side of a dashboard panel and includes an outside end portion in the vehicle width direction coupled to the rocker; a second cross member that extends in the vehicle width direction at the vehicle body front side of the first cross member; and a coupling member that couples the first cross member and the second cross member together, and configures a closed cross-section structure with the dashboard panel and/or the floor panel.

Vehicle body lower section structure

A laser welding method of the present disclosure includes a first step, a second step, and a third step. In the first step, a first workpiece and a second workpiece are stacked on each other. Each of the first workpiece and the second workpiece has a surface coated with a first material and is made of a second material, which is different from the first material. In the second step, a first region in which the first workpiece and the second workpiece are stacked on each other is irradiated with a laser beam so that the laser beam penetrates both the first workpiece and the second workpiece. In the third step, a second region including the first region is irradiated with a laser beam in a spiral fashion.

Laser welding method and laser welding device

PROBLEM TO BE SOLVED: To provide a welded portion inspection device and a welded portion inspection method capable of accurately inspecting a welded sate of a welded portion of a workpiece in remote welding for welding a workpiece with, for example, the workpiece being distant from a laser torch.SOLUTION: In the welded portion inspection device, welding laser beam L1 is emitted along welding trajectories C11 and C12 set to workpieces W1 and W2, respectively or inspection laser beam L5 is emitted along scan trajectories C51 and C52 set to a molten weld pool Y1 of the workpieces W1 and W2 welded by the welding laser beam L1. The welded portion inspection device receives return light L2 containing reflected light by the molten weld pool Y1 of the workpieces, steam emitted light generated by molten steam of the workpieces, and heat radiation light radiated from the molten weld pool Y1 of the workpieces, detects a fundamental frequency by performing a Fourier transform on an intensity of the received return light L2, and inspects a welded state of a welded portion of each of the workpieces on the basis of amplitude at the fundamental frequency and amplitude at a frequency twice as high as the fundamental frequency.

Welded portion inspection device and inspection method

Provided are: a laser-bonded structure wherein deterioration of strength or rigidity of a third plate is suppressed, said third plate being disposed by being spaced apart from at least two metal plates; and a laser bonding method. The laser-bonded structure is provided with: at least two metal plates, which have two or more overlapping portions where the metal plates are disposed in a state wherein the metal plates are overlapping each other, and which are bonded by means of laser welding sections; and a third plate that is disposed by being spaced apart from the overlapping portions. The third plate has formed therein penetrating sections of a number smaller than the number of the laser welding sections, said penetrating sections penetrating the third plate, and having laser light radiated to the overlapping portions.

Laser joining structure and laser joining method

A laser welding method includes: projecting a laser beam onto irradiation regions on plural metallic workpieces such that a weld section is formed when the workpieces are joined by laser welding, the weld section being formed of plural nuggets, and each of the irradiation regions being formed with each of the nuggets. The nuggets are sequentially formed by sequentially projecting the laser beam onto the irradiation regions that respectively correspond to the nuggets. The laser beam is projected onto each of the irradiation regions such that an amount of input heat from the laser beam that is projected onto each of the irradiation regions to the workpiece is reduced as the nuggets are sequentially formed.

Provided is a measuring method for measuring laser scanning velocity for a laser beam machining apparatus (1). The laser beam machining apparatus (1) includes a mirror (7,8), and processes a work by irradiating laser (PL). The laser (PL) is irradiated by operating the mirror (7,8). The measuring method includes measuring processing sound of the work by the laser (PL) using the laser beam machining apparatus (1). Further, the measuring method includes calculating scanning velocity of the laser (PL) by analyzing a frequency of the measured processing sound using the laser beam machining apparatus (1).

Measuring method for measuring laser scanning velocity

A welding method for joining together a plurality of welding objects by overlapping the plurality of welding objects and performing laser welding includes forming a weld by forming a plurality of nuggets along a virtual closed curve on the welding objects, by laser welding. A ratio of a diameter of the nuggets to a pitch dimension between the nuggets that are adjacent to each other is larger than 1/2 and no more than 1.

Welding method and welding structure

A method of joining together by welding a plurality of welding objects (2, 4) by overlapping the plurality of welding objects (2, 4) and performing laser welding includes forming a weld by forming a plurality of nuggets (12a-f) along a virtual closed curve (14) on the welding objects (2, 4), by laser welding. A ratio of a diameter of the nuggets (12a-f) to a pitch dimension between the nuggets (12a-f) that are adjacent to each other is larger than 1 / 2 and no more than 1.

Method of joining by welding together a plurality of welding objects and corresponding welding structure

Eine Punktschweiselektrode (1) umfasst eine Kupferlegierung (3) und eine in einem Spitzenabschnitt der Punktschweiselektrode (1) angeordnete Wolframsinterlegierung (2), wobei der Spitzenabschnitt der Punktschweiselektrode (1) mit einem Schweisobjekt in Kontakt gebracht wird. Die Wolframsinterlegierung (2) ist mit der Kupferlegierung nur an einer einzigen flachen Oberflache (3) verbunden. Eine Warmeleitfahigkeit der Punktschweiselektrode (1) liegt in einem Bereich von 60 W/mK bis 120 W/mK.

Kazuyuki Ogusu

Papers

Laser welding method

Measuring method for measuring laser scanning velocity

Welding method and welding structure

Method of joining by welding together a plurality of welding objects and corresponding welding structure

Spot welding electrode