Abstract: A method of manufacturing a joined body includes joining a first plate portion and a second plate portion together by forming a penetration portion extending from the second plate portion to the first plate portion in a region where a weld bead is formed. The weld bead includes a first weld portion, a second weld portion, and a third weld portion. The first weld portion and the second weld portion form a loop portion as a loop-shaped weld portion. A terminal end of the third weld portion as a terminal end of the weld bead is formed on an inner peripheral side of the loop portion. An amount of heat supplied to a region to be heated during formation of the third weld portion is controlled to be smaller than an amount of heat supplied to the region to be heated during formation of the first weld portion.

Abstract: In a manufacturing method of a tailored blank including a first steel plate and a second steel plate to be joined by butt welding, the first and second steel plates are butt welded with a laser beam. The laser beam has a power density q1 in a first region, a power density q2 in a second region, a power density q3 in a third region, and a power density q4 in a fourth region. The power density q1, the power density q2, the power density q3, and the power density q4 satisfy a relationship of q1>q2>q3>q4.

Abstract: Provided is a mobile removal device. The mobile removal device includes a camera, a laser oscillator, a controller, and a guide portion. The guide portion includes one or more reflectors configured to reflect a laser beam. At least one of the one or more reflectors is a specific reflector having a function of reflecting the laser beam and a function of transmitting a light that can be captured by the camera. The camera is arranged so that an optical axis of the camera passes through the specific reflector in an area where the laser beam does not pass through.

Abstract: In a manufacturing method of a tailored blank including a first steel plate and a second steel plate to be joined by butt welding, the first and second steel plates are butt welded with a laser beam. The laser beam has a power density q1 in a first region, a power density q2 in a second region, a power density q3 in a third region, and a power density q4 in a fourth region. The power density q1, the power density q2, the power density q3, and the power density q4 satisfy a relationship of q1>q2>q3>q4.

Abstract: A manufacturing method of a component includes a method for welding base materials with each other by laser welding, in which welding is performed by irradiating a laser beam along a welding line. The manufacturing method of a component includes, before starting the welding along the welding line, increasing an output power of the laser beam, while repeatedly moving an irradiation position of the laser beam in a neighborhood of a start point of the welding line, repeatedly moving the irradiation position of the laser beam at least between a first point and a second point. The first point is the start point. The second point is different from the first point.