Process and device for machining workpieces by means of a laser beam
AssigneeMAHO Aktiengesellschaft
InventorsMichael Kuhl, Alfred Zwick, Gunter Eberl
Life of this patent
Estimating the term…
Abstract
A process for precision control of a laser beam for machining workpieces while achieving high surface quality. The actual distance between a reference location and the workpiece surface is determined. A setpoint/actual value deviation between a predetermined setpoint distance and the actual distance measured is also determined. Control parameters are determined by a control unit in accordance with the setpoint/actual value deviation. The resulting control parameter outputs are coupled to a laser control unit to control the beam power of the laser. The disclosure also includes the apparatus for accomplishing the process.
Claims35
A process for machining workpieces by means of a laser beam, whereby the workpiece is machined by the laser beam line-by-line and layer-by-layer in thin layers that follow each other closely, the process comprising the steps of:
- comparing new machining layer K, a setpoint distance (A.sub.soll k-1) of the preceding machining layer k-1 with a measured actual distance (A.sub.ist k) of the present machining layer;
- determining a distance difference (.DELTA.A.sub.k) from the result;
- and
- correcting at least one control parameter in accordance with the distance difference (.DELTA.A.sub.k).
A device for machining workpieces by means of a laser beam, said device comprising:
- a measurement unit for detecting process parameters;
- a laser stimulating unit for controlling the laser;
- and
- an electronic control unit for processing measurement signals (Sa, Sm) from the measurement unit and for controlling a controller;
- said measurement unit having a distance sensor, said control unit being configured to have:
- means for determination of an actual distance (A.sub.ist) from a signal (Sa) of said distance sensor, where the actual distance (A.sub.ist) corresponds to the distance between a reference point and the workpiece surface at the machining location;
- means for determination of a setpoint/actual value deviation (.DELTA.A.sub.i) between a given setpoint distance (A.sub.soll) and the actual distance (A.sub.ist) thus determined;
- means for determination at least one control parameter corresponding to the setpoint/actual value deviation (.DELTA.A.sub.i);
- and
- means for coupling the control parameter to said controller.
A process for machining workpieces by means of a laser beam directed to a machining location on a workpiece having a surface exposed to the laser beam, the process comprising the steps of:
- regulating the process by means of a control unit having control parameter outputs to a laser control unit for selectively controlling parameters of the laser beam, the parameters being selected from the group consisting of laser beam power, intensity of the laser radiation, and laser beam power and the intensity of the laser radiation;
- determining an actual distance (.DELTA..sub.ist) between a reference location and the workpiece surface of the machining location;
- determining a setpoint/actual value deviation (.DELTA.A.sub.i) between a given setpoint distance (A.sub.soll) and the actual distance (A.sub.ist) measured;
- determining at least one control parameter by the control unit in accordance with the setpoint/actual value deviation (.DELTA.A.sub.i);
- and
- coupling the control parameter output thus determined to a control unit.
A process for machining workpieces by means of a laser beam directed to a machining location on a workpiece having a surface exposed to the laser beam, the process comprising the steps of:
- regulating the process by means of a control unit having control parameter outputs to a laser control unit for selectively controlling the laser beam power and the intensity of the laser radiation;
- determining an actual distance (A.sub.ist) between a reference location and the workpiece surface of the machining location;
- determining a setpoint/actual value deviation (.DELTA.A.sub.i) between a given setpoint distance (A.sub.soll) and the actual distance (A.sub.ist) measured;
- determining at least one control parameter by the control unit in accordance with the setpoint/actual value deviation (.DELTA.A.sub.i);
- and
- coupling the control parameter;output thus determined to a control unit.
A process for machining workpieces by means of a laser beam directed to a machining location on a workpiece having a surface exposed to the laser beam, the process comprising the steps of:
- regulating the process by means of a control unit having control parameter outputs to a laser control unit for selectively controlling the laser beam power and the intensity of the laser radiation;
- determining an actual distance (A.sub.ist) between a reference location and the workpiece surface of the machining location;
- determining a setpoint/actual value deviation (.DELTA.A.sub.i) between a given setpoint distance (A.sub.soll) and the actual distance (A.sub.ist) measured;
- determining at least one control parameter by the control trait in accordance with the setpoint/actual value deviation (.DELTA.A.sub.i);
- coupling the control parameter output thus determined to a control unit;
- and
- regulating the laser beam as applied to the workpiece selectively by one or both of:
- moving the workpiece with respect to the laser beam, the relative forward speed of the workpiece being regulated as a control parameter by speed-modulated control pulses (Pg);
- regulating the beam power of the laser and/or the intensity of the laser radiation at the workpiece pursuant to a control parameter and selectively by means of amplitude-modulated, pulse-width modulated and/or frequency-modulated controlled pulses (Pa,w,p) by controlled defocusing of the laser beam and/or by means of a shutter.
A process for machining workpieces by means of a laser beam directed to a machining location on a workpiece having a surface exposed to the laser beam, the process comprising the steps of:
- regulating the process by means of a control unit having control parameter outputs to a laser control unit for selectively controlling parameters of the laser beam, the parameters being selected from the group consisting of laser beam power, intensity of the laser radiation, and laser beam power and the intensity of the laser radiation;
- determining an actual distance (A.sub.ist) between a reference location and the workpiece surface of the machining location;
- determining a setpoint/actual value deviation (.DELTA.A.sub.i) between a given setpoint distance (A.sub.soll) and the actual distance (A.sub.ist) measured;
- determining at least one control parameter by the control unit in accordance with the setpoint/actual value deviation (.DELTA.A.sub.i);
- coupling the control parameter output thus determined to a control unit;
- and regulating the laser beam as applied to the workpiece selectively by one or both of:
- moving the workpiece with respect to the laser beam, the relative forward speed of the workpiece being regulated as a control parameter by speed-modulated control pulses (Pg);
- regulating the beam power of the laser and/or the intensity of the laser radiation at the workpiece pursuant to a control parameter and selectively by means of amplitude-modulated, pulse-width modulated and/or frequency-modulated controlled pulses (Pa,w,p) by controlled defocusing of the laser beam and/or by means of a shutter.
Dependencies are inferred from the claim text.