| 摘要 |
The laser beam (3) of the laser machine tool, after passing through a nozzle (5) in a focused manner, strikes the workpiece (4) to be machined, in which it burns a hole for example. A gas can come out with the laser beam via the nozzle orifice (6). The gas can be used at least partly for cooling purposes. Intensified cooling of the instantaneous burning point is obtained if additional fluid is supplied outside the nozzle. The additional fluid should strike the instantaneous burning point as accurately as possible. This is best achieved if the tapering, in particular conical or frustoconical, nozzle (5) is surrounded by a sleeve (8) and the fluid is allowed to flow between nozzle and sleeve. The direction of flow is thereby exactly predetermined. It is advantageous if only individual fluid jets come out which cross approximately in the area of the instantaneous burning point. This is achieved in a simple manner by longitudinal grooves (11) being made in the outer circumference (10) of the nozzle (5) and/or in the inner circumference (9) of the sleeve (8). The longitudinal grooves (11) are then covered by the respective other part to form longitudinal passages. Increased demand for fluid is satisfied by lifting the sleeve (8) slightly from the nozzle (5) towards the workpiece, a screwing motion being given preference to a longitudinal displacement for sensitive metering. <IMAGE> |
