Structure of metal container having trunk pipe and branch pipe, and manufacturing method and apparatus therefor

A matching head comprising:

• a generally cylindrical nozzle for guiding a laser beam from a laser oscillator in the vicinity of a workpiece to be machined;
• a condensing lens disposed midway in said nozzle for condensing said laser beam to irradiate said workpiece with the condensed laser beam;
• shield gas introducing means for introducing a shield gas which is used to shield the laser beam in said nozzle against a wall surface and which is to be sprayed to said workpiece while guiding said laser beam;
• and a guide in the form of a nozzle arranged around the outer circumference of the first-named nozzle and made vertically movable while being guided by the outer wall of the first-named nozzle such that said nozzle has its tip aperture made variable by the vertical movements of said guide.

A laser machining system comprising:

• first conveyor means for conveying a trunk pipe having a branch pipe fixed in advance to its predetermined portion;
• a cutting station for cutting the branched trunk pipe conveyed by said conveyor means;
• a flange assembling station for assembling each of these ends of said branched trunk pipe conveyed by said first conveyor means, which were cut at said cutting station, with the flange which is conveyed by second conveyor means arranged generally at a right angle with respect to said first conveyor means;
• and a welding station for welding each of those ends of the branched trunk pipe conveyed by said first conveyor means, which were assembled with a flange at said flange assembling station, and the flange-assembled portion of the same with a laser beam, wherein said cutting station includes:
• rails arranged generally at a right angle with respect to the conveyance direction of said first conveyor means;
• a turntable made movable on said rails in a direction perpendicular to the conveyance direction of said first conveyor means and turntable in a horizontal direction;
• and a swivel table having a swivel axis aligned generally with the center axis of said branched trunk pipe to be cut on said turntable, so that said swivel table can swing on said swivel axis at a right angle with respect to the turning direction of said turntable, said swivel table including a cutting head for radiating a laser beam coming from a laser oscillator so as to cut each of the ends of said branched trunk pipe.

A laser machining system comprising:

• first conveyor means for conveying a trunk pipe having a branch pipe fixed in advance to its predetermined portion;
• a cutting station for cutting the branched trunk pipe conveyed by said conveyor means;
• a flange assembling station for assembling each of these ends of said branched trunk pipe conveyed by said first conveyor means, which were cut at said cutting station, with the flange which is conveyed by second conveyor means arranged generally at a right angle with respect to said first conveyor means;
• and a welding station for welding each of those ends of the branched trunk pipe conveyed by said first conveyor means, which were assembled with a flange at said flange assembling station, and the flange-assembled portion of the same with a laser beam, wherein said welding station includes:
• rails arranged generally at a right angle with respect to the conveyance direction of said first conveyor means;
• a turntable made movable on said rails in a direction perpendicular to the conveyance direction of said first conveyor means and turntable in a horizontal direction;
• and a swivel table having a swivel axis aligned generally with the center axis of the flange-assembled branched trunk pipe to be welded on said turntable, so that said swivel table can swing on said swivel axis at a right angle with respect to the turning direction of said turntable, said swivel table including a welding head for radiating a laser beam coming from a laser oscillator so as to weld each of the ends of said branched trunk pipe and said flange.

A machining head comprising:

• a generally cylindrical nozzle for guiding a laser beam from a laser oscillator in the vicinity of a workpiece to be machined;
• a condensing lens disposed midway in said nozzle for condensing said laser beam to irradiate said workpiece with the condensed laser beam;
• shield gas introducing means for introducing a shield gas which is used to shield the laser beam in said nozzle against a wall surface and which is to be sprayed to said workpiece while guiding said laser beam;
• and a guide in the form of a nozzle arranged around the outer circumference of the first-named nozzle and made vertically movable while being guided by the outer wall of the first-named nozzle such that said nozzle has its tip aperture made variable by the vertical movements of said guide, and wherein said shield gas introducing means including a switch mechanism for switching the shield gas to be introduced in accordance with the machining application of said workpiece.