Laser processing method, laser processing device, and method for producing laser processed product

A laser processing device, comprising:

• a processing head configured to emit a laser beam;
• and
• a controller configured to control emission of the laser beam and movement of the processing head on a predetermined path, wherein
• when the controller controls a workpiece including a first plate-shaped part and a second plate-shaped part connecting to the first plate-shaped part in a direction to cross the first plate-shaped part such that the workpiece is cut with the laser beam,
• the controller is configured to
• set a cutting line across the first plate-shaped part and the second plate-shaped part,
• form a notch portion in the second plate-shaped part by controlling emission of the laser beam and movement of the processing head so that a cutout piece cut out by forming the notch portion is divided into a tip end portion and a base portion, the notch portion opening to a tip end portion of the second plate-shaped part and being along the cutting line, and
• control emission of the laser beam and movement of the processing head so as to cut the first plate-shaped part along the cutting line by irradiation with the laser beam from one direction.

A method for producing a laser processed product, comprising:

• setting a cutting line across a first plate-shaped part and a second plate-shaped part to a workpiece including the first plate-shaped part and the second plate-shaped part connected to the first plate-shaped part in a direction to cross the first plate-shaped part;
• forming, by cutting with a laser beam, a notch portion in the second plate-shaped part so that a cutout piece cut out by forming the notch portion is divided into a tip end portion and a base portion, the notch portion opening to a tip end portion of the second plate-shaped part and being along the cutting line;
• and
• producing a laser processed product by cutting the first plate-shaped part along the cutting line by irradiation with the laser beam from one direction, in a state where at least the base portion of the cutout piece is removed.