Laser cutting machine

A laser cutting method using a laser cutting machine for cutting a workpiece while concurrently measuring a distance between a cutting head and a workpiece and operating a copy control section which controls said distance between said cutting head and said workpiece, said laser cutting method comprising the steps of:

• (1) determining whether said laser cutting machine is in a piercing mode;
• (2) when said laser cutting machine is in said piercing mode, invalidating an alarm signal which has been generated to prevent an alarm from being displayed and to continue cutting, wherein said invalidating step is performed even when said copy control section is not invalidated;
• and
• (3) when said laser cutting machine is not piercing, displaying said alarm signal and stopping said cutting.

A laser cutting machine having a laser oscillator, an optical condenser system for directing a laser beam output from said laser oscillator onto a workpiece, a cutting head for holding said optical condenser system therein, distance measuring means for measuring a distance between said cutting head and said workpiece, a copy control section for controlling said distance between said cutting head and said workpiece, an alarm signal output section for judging an excess of an output signal of said distance measuring means over a predetermined range as an alarm state and providing an alarm signal, and an alarm display section for receiving said alarm signal from said alarm signal output section and displaying an alarm, said laser cutting machine further comprising:

• block checking means for checking whether said laser cutting machine is moving in a first moving command block of a numerical control program after a completion of piercing;
• a distance condition judging section for judging whether a travel distance from a piercing point to a current cutting point is less than a preset distance;
• and
• alarm signal invalidating means for invalidating said alarm signal when said block checking means determines that said laser cutting machine is moving in a first moving command block after a completion of piercing and said distance condition judging section determines that said travel distance is less than said preset distance, even when said copy control section is not invalidated.

A laser cutting machine having a laser oscillator, an optical condenser system for directing a laser beam output from said laser oscillator onto a workpiece, a cutting head for holding said optical condenser system therein, distance measuring means for measuring a distance between said cutting head and said workpiece, a copy control section for controlling said distance between said cutting head and said workpiece, an alarm signal output section for judging an excess of an output signal of said distance measuring means over a predetermined range as an alarm state and for providing an alarm signal, and an alarm display section for receiving the alarm signal from said alarm signal output section and displaying an alarm, said laser cutting machine further comprising:

• piercing checking means for checking whether said laser cutting machine is piercing;
• block checking means for checking whether said laser cutting machine is moving in a first moving command block of a numerical control program after a completion of piercing;
• a distance condition judging section for judging whether a current cutting point has moved a preset distance from a piercing point on said workpiece;
• and
• alarm signal invalidating means for invalidating said alarm signal when said piercing checking means determines that said laser cutting machine is piercing, or when said block checking means determines that said laser cutting machine is moving in a first moving command block after a completion of piercing and said distance condition judging section determines that a current cutting point has moved a preset distance from a piercing point, even when said copy control section is not invalidated.

A laser cutting method using a laser cutting machine for cutting a workpiece while concurrently measuring a distance between a cutting head and the workpiece and operating a copy control section which controls said distance between said cutting head and said workpiece, said laser cutting method comprising the steps of:

• (1) determining whether the laser cutting machine is piercing;
• (2) if the laser cutting machine is not piercing, determining whether the machine is in a first moving command block of a numerical control program after a completion of piercing;
• (3) if the laser cutting machine is in the first moving commend block after the completion of piercing, judging whether a travel distance from a piercing point to a current cutting point is less than a preset distance;
• (4) when the laser cutting machine is piercing, or when the laser cutting machine is moving in the first moving command block after the completion of piercing and said travel distance is less than said preset distance invalidating an alarm signal which has been generated to prevent an alarm from being displayed and to continue cutting, wherein said invalidating step is performed even when said copy control section is not invalidated;
• and
• (5) when the laser cutting machine is not piercing and is moving in the first moving command block after the completion of piercing and said travel distance has exceeded said preset distance, or when the laser cutting machine is not in the first moving command block after the completion of piercing, displaying an alarm signal and stopping the cutting.

A laser cutting machine having a laser oscillator, an optical condenser system for directing a laser beam output from said laser oscillator onto a workpiece, a cutting head for holding said optical condenser system therein, distance measuring means for measuring a distance between said cutting head and said workpiece, an alarm signal output section for judging an excess of an output signal of said distance measuring means over a predetermined range as an alarm state and providing an alarm signal, and an alarm display section for receiving said alarm signal from said alarm signal output section and displaying an alarm, said laser cutting machine further comprising:

• block checking means for checking whether said laser cutting machine is moving in a moving command block of a numerical control program immediately before a completion of piercing;
• a distance condition judging section for judging whether a cutting point cutting point is within a preset distance from a specific cutting end point on said workpiece;
• and
• alarm signal invalidating means for invalidating said alarm signal when said block checking means determines that said laser cutting machine is moving in a moving command block immediately before a completion of cutting and when said distance condition judging section determines that said current cutting point is within said preset distance.

A laser cutting method using a laser cutting machine for cutting a workpiece while concurrently measuring a distance between a cutting head and a workpiece, said laser cutting method comprising the steps of:

• (1) determining whether said laser cutting machine is moving in a moving command block of a numerical control program immediately before a completion of cutting;
• (2) when the laser cutting machine is moving in the moving command block immediately before the completion of cutting, determining whether a travel distance from a cutting completion point to a current cutting point is within a preset distance;
• (3) when said travel distance is not more than said preset distance, invalidating an alarm signal which has been generated to prevent an alarm from being displayed and to continue the cutting;
• and
• (4) when said travel distance has exceeded said preset distance or when the current cutting point is not in the moving command block immediately before the completion of cutting, displaying the alarm signal and stopping the cutting.

A laser cutting method using a laser cutting machine for cutting a workpiece while concurrently measuring a distance between a cutting head and a workpiece and operating a copy control section which controls said distance between said cutting head and said workpiece, said laser cutting method comprising the steps of:

• (1) determining whether said laser cutting machine is moving in a first moving command block of a numerical control program after a completion of piercing;
• (2) when said laser cutting machine is moving in the first moving command block after the completion of piercing, judging whether a travel distance from a piercing point to a current cutting point is less than a preset distance;
• (3) when said travel distance is less than said preset distance, invalidating an alarm signal which has been generated to prevent an alarm from being displayed and to continue a cutting, even when said copy control section is not invalidated;
• and
• (4) when said travel distance has exceeded said preset distance or when the current cutting point is not in the first moving command block after the completion of piercing, displaying the alarm signal and stopping the cutting.