APPARATUS FOR MACHINING A WORKPIECE WITH A LASER BEAM COUPLED INTO A FLUID JET, WITH AUTOMATIC LASER-NOZZLE ALIGNMENT ; METHOD OF ALIGNING SUCH A BEAM

摘要

The invention relates to an apparatus (100) for machining a workpiece with a laser beam (101) coupled into a fluid jet. The apparatus (100) comprises a laser unit (101a) for providing the laser beam (101), a nozzle unit (102) with an aperture (102a) for producing the fluid jet, and an optical unit (103) configured to provide the laser beam (101) from the laser unit (101a) onto the nozzle unit (102). Further, the apparatus (100) comprises a control unit (104) configured to control (108, 110) the optical unit (103) and/or nozzle unit (102) to change a point of incidence (109) of the laser beam (101) on the nozzle unit (102). The apparatus (100) also comprises a sensing unit (105) configured to sense laser light (106) reflected from a surface (102b) of the nozzle unit (102) and produce a sensing signal (107) based on the sensed reflected laser light (106). The control unit (104) is particularly configured to evaluate the sensing signal (107) and to determine a defined sensing pattern in the sensing signal (107) indicative of the laser beam (101) being fully and/or partially aligned with the aperture (102a).