US Patent 10166603 Metal 3D printer

A metal 3D printer includes: a housing (1) forming a molding chamber (1B); a recoater head (3) reciprocating in the direction of a horizontal U axis in the molding chamber to form a powder layer of a metal; a laser irradiation device (9) irradiating an irradiation region in the powder layer with a laser beam to form a sintered layer; and an inert gas supply device (4). The inert gas supply device includes: a first suction port (V1) disposed on one (14) of the side walls facing each other in the direction of the U axis, which is far away from the irradiation region; a first blowout port (F1) disposed on a side of the recoater head to face the first suction port; and a second blowout port (F2) disposed to face the first suction port across the irradiation region.