Abstract: A method of producing a metal tubular member that is composed of two or more tube forming bodies and has at least one portion at which the tube forming bodies are superposed on each other, wherein one open annular end section of one of the tube forming bodies, which one annular end section is positioned on the inner side in the superposed section, and the other open annular end section of the other tube forming body, which the other annular end section is positioned on the outer side, are integrally joined by welding. The one annular end section is inserted into the other annular end section with the outside diameter of the one annular end section pressed by a die so as to be smaller in diameter than the inside diameter of the other annular end section, and then pressing force applied to the one annular end section on the inner side is released to cause it to be in tight contact with the inner surface of the other annular end section on the outer side.

Abstract: A laser processing device in which even a short nozzle provided with a follower roller (35) can prevent disturbance of a laser beam and contamination of protective glass and in which shield gas can act effectively. The laser processing device comprises a head section (11) from which a laser beam that is condensed by a condenser lens (16) provided inside the device is irradiated through a nozzle section (13); a gas delivery means (28) opened in a processing direction X, in the vicinity of the focal point of laser beam, and jetting a shield gas from the opening; a primary air delivery means (31) directed in the processing direction X, above the focal point F of the laser beam, and jetting primary air A1 substantially in the horizontal direction to form a first air curtain; and secondary air delivery means (18, 13, 19) directed to the focal point from the vicinity of the condenser lens and jetting secondary air A2 to form a second air curtain.

Abstract: A laser processing device in which even a short nozzle provided with a follower roller (35) can prevent disturbance of a laser beam and contamination of protective glass and in which shield gas can act effectively. The laser processing device comprises a head section (11) from which a laser beam that is condensed by a condenser lens (16) provided inside the device is irradiated through a nozzle section (13); a gas delivery means (28) opened in a processing direction X, in the vicinity of the focal point of laser beam, and jetting a shield gas from the opening; a primary air delivery means (31) directed in the processing direction X, above the focal point F of the laser beam, and jetting primary air A1 substantially in the horizontal direction to form a first air curtain; and secondary air delivery means (18, 13, 19) directed to the focal point from the vicinity of the condenser lens and jetting secondary air A2 to form a second air curtain.

Abstract: A method of producing a metal tubular member that is composed of two or more tube forming bodies and has at least one portion at which the tube forming bodies are superposed on each other, wherein one open annular end section of one of the tube forming bodies, which one annular end section is positioned on the inner side in the superposed section, and the other open annular end section of the other tube forming body, which the other annular end section is positioned on the outer side, are integrally joined by welding. The one annular end section is inserted into the other annular end section with the outside diameter of the one annular end section pressed by a die so as to be smaller in diameter than the inside diameter of the other annular end section, and then pressing force applied to the one annular end section on the inner side is released to cause it to be in tight contact with the inner surface of the other annular end section on the outer side.