Patent ID: 6118097
Filing Date: 2000-09-12
Classification: B23K

Abstract:
A machining head of a laser machining apparatus through which a laser beam passes, comprising:a main assist gas nozzle at a center portion of the machining head for supplying a main assist gas;at least one annular sub assist gas nozzle surrounding the main assist gas nozzle, a jet outlet at an innermost diameter of the annular sub assist gas nozzle being no smaller than a jet outlet of the main assist gas nozzle, for increasing pressure fluctuation and flow fluctuation of the main assist gas flow in comparison with the sub assist gas flow;a static pressure conversion surface which converts dynamic pressure of an assist gas which flows into the sub assist gas nozzle through a sub assist gas supply inlet into static pressure; anda return wall surface protruding at an edge of said static pressure conversion means toward said sub assist gas supply inlet, said return wall surface forming a gas residence space that is not a through conduit where said sub assist gas stays to recover static pressure, said gas residence space being defined by said return wall surface, an inside wall of said sub assist nozzle and said static pressure conversion surface.