Laser machining apparatus using laser beam introduced into jet liquid column

A laser machining apparatus comprising a laser oscillator for generating a laser beam, a nozzle for ejecting a jet liquid to a workpiece, and liquid supply means for supplying the jet liquid to the nozzle, the laser beam being introduced into a jet liquid column ejected from the nozzle, the laser machining apparatus further comprising:

• a laminar flow forming channel for supplying the jet liquid to the nozzle in a laminar state,
• the laminar flow forming channel including:
• a distribution channel formed by a cavity for annually distributing the jet liquid, which is supplied from the liquid supply means, around an axis of the nozzle;
• an interconnecting channel disposed to be communicated with the distribution channel at the downstream side thereof in an axial direction of the nozzle and formed by an annular cavity around the axis of the nozzle to provide a narrower flow passage than the distribution channel;
• and
• a liquid reservoir chamber adjacently disposed upstream of the nozzle in the axial direction thereof and storing the jet liquid to be supplied to the nozzle,
• a depth of the liquid reservoir chamber in the direction of the nozzle axis being set to a value in the range of 2 to 40 mm, and
• the liquid reservoir chamber having an outer peripheral edge being communicated with the interconnecting channel over an entire circumference of the annular shape thereof.