Being method in order to improve the reliability of machining processing and

摘要

A process for providing a protection against damages in a machine head, wherein the machine head launches a transparent liquid jet guided laser beam LB by means of a nozzle 3 along an optical axis for treating a work piece is claimed. The process comprises the following steps: First a blind steel plate (protection plate 20) is fixed to a front of a protection chamber (10) prior to the liquid water jet (WJ). Then the transparent liquid jet (WJ) guided laser beam (LB) is stared, which impinges on the blind steel plate (20) blank and drills a transit-hole into the blind steel plate blank. The transit-hole (23) has a size which substantially corresponds to a cross-section of the laser beam (LB) guiding transparent liquid jet (WJ). The steel plate (20) with the transit-hole (23) provides a protection plate (20) having the transit-hole (23) precisely arranged on the optical axis. Therefore no further alignment is required. Further an apparatus for treating a workpiece by means of a laser beam (LB) which is guided in a transparent liquid jet (WJ) is claimed. The apparatus comprises a laser head with a coupling unit (CU) for producing a liquid jet (WJ) guided laser beam (LB), a protection chamber (10) mounted on the output (5) of the coupling unit (CU) and a protection plate (20) replaceable fixed to the first chamber (10) and mounted at a distance from the outlet (15) of the first chamber (10) and having a hole (23) for passage of the laser beam (LB) guiding transparent liquid jet (WJ) and protecting the outlet (15) of the first chamber (10) from debris sputtered from the treated workpiece.