Laser cutting method and machine, and automatic programing apparatus

A laser cutting machine cutting a processed part from a plate-shaped workpiece, comprising:

• a laser processing head relatively movable in X-, Y- and Z-directions with respect to the workpiece;
• and
• a control device configured to control an operation of the laser processing head, wherein
• the control device comprises:
• a processing program memory configured to store a processing program for laser-cutting the processed part;
• a program analyzer configured to analyze the processing program and calculate a shape and dimensions of the processed part;
• a weight arithmetic section configured to calculate a weight of the processed part based on the shape and dimensions of the processed part that are analyzed, and a thickness of the workpiece;
• a number arithmetic section configured to calculate a number of welding protruding-tabs each of which bends and causes a free end of the welding protruding-tab to be welded to a peripheral surface of the processed part when an outline slit is formed by laser cutting along an outline of the processed part, based on an arithmetic calculation result of the weight arithmetic section;
• a welding protruding-tab arranger configured to arrange the welding protruding-tab in a periphery of the processed part, based on an arithmetic calculation result of the number arithmetic section;
• a processing program generator configured to generate a laser cutting program for forming the welding protruding-tab in a position arranged by the welding protruding-tab arranger;
• the processing program memory configured to store the laser cutting program generated by the processing program generator;
• and
• an axial motion controller configured to control axial motion of the laser processing head in accordance with the laser cutting program stored in the processing program memory.

An automatic programming apparatus of a laser cutting machine, comprising:

• a weight arithmetic section configured to calculate a weight of a processed part based on a shape and dimensions of the processed part and a thickness t of a workpiece that are input from CAD;
• a number arithmetic section configured to calculate a number of welding protruding-tabs each of which bends and causes a free end of the welding protruding-tab to be welded to a peripheral surface of the processed part when an outline slit is formed by laser cutting along an outline of the processed part, based on an arithmetic calculation result of the weight arithmetic section;
• a welding protruding-tab arranger configured to arrange the welding protruding-tab in a periphery of the processed part, based on an arithmetic calculation result of the number arithmetic section;
• a processing program generator configured to generate a laser cutting program for forming the welding protruding-tab in a position arranged by the welding protruding-tab arranger, and laser-cutting the processed part;
• a processing program memory configured to store the laser cutting program generated by the processing program generator;
• and
• a program transferrer configured to transfer the laser cutting program stored in the processing program memory to a control device of the laser cutting machine.