Apparatus and method for laser cutting with a laser implementing gas pulses, the frequency or pressure of which is controlled
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorJean-Pascal Alfille
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Abstract
The head (9) of the cutting apparatus (4) of the laser comprises a gas supply through a device such as a barrel dispenser which chops the blowing flow rate, which produces a better discharge of the liquid slag melt by the laser beam (16, 18) out of the plate (19) to be cut. A measurement (36) of backscattered light is made in order to check the good quality of cutting, the amount measured being smaller if the cutting actually passes through the plate (19), and the frequency or the pressure of the blowing pulses is adjusted by a controlling device (39) to keep the measure to a minimum by optimizing the slag discharge conditions.
Claims9
An automatic cutting method, comprising blowing a gas flow rate to a cutting location in order to sweep slag and gases produced by cutting, the blowing being performed through pulses, characterised in that it consists in continuously measuring a laser light backscatter intensity and modifying either a frequency, a pressure or both a frequency and a pressure of the pulses so as to keep said intensity to a minimum.
A cutting apparatus, comprising a laser head (9) and a gas blowing auxiliary, the auxiliary comprising a gas supplying duct (13, 15) and a gas blowing nozzle (11, 29), downstream of the supplying duct, the nozzle being directed to the cutting location, the auxiliary comprising a device (12, 24;
- 141, 142, 143) for splitting blowing into discontinuous repeated pulses, characterised in that the laser is a continuous beam laser having a power higher than 1 kW and the apparatus comprises a detector (36) having a light power backscattered by the cutting location and a device (39) for controlling either frequency or pressure, or frequency and pressure of the pulses in response to measurements of the detector.
Dependencies are inferred from the claim text.