Laser beam machine

A laser beam machine comprising:

• a laser emitting system for emitting a laser beam, wherein the laser emitting system has a protective glass capable of transmitting the laser beam;
• and
• a housing attached to the laser emitting system,
• wherein the housing comprises a cylindrical shape and is arranged to surround an optical path of the laser beam emitted from the laser emitting system,
• wherein the housing further comprises:
• a first end facing the laser emitting system;
• a second end opposite to the first end;
• a first blowing portion comprising a first slit-shaped opening located over an entire circumference of an interior of the first end,
• wherein the first slit-shaped opening blows a gas toward a central axis of the housing;
• a first supply passage located over the entire circumference of an inside of the housing,
• wherein the first supply passage supplies the gas to the first blowing portion;
• a plurality of first gas inlets for introducing the gas into the first supply passage,
• wherein the first supply passage comprises a plurality of distribution portions for dividing a gas flow,
• wherein the plurality of distribution portions comprises a first distribution portion and a second distribution portion,
• wherein the first distribution portion is located in vicinity of each of the plurality of first gas inlets in the first supply passage, the first distribution portion is configured to flow the gas toward a circumferential direction of the housing,
• wherein the gas flowed toward the circumferential direction of the housing is introduced from the plurality of first gas inlets,
• wherein the second distribution portion is located between one of the plurality of first gas inlets and another of the plurality of first gas inlets, and
• wherein the first distribution portion and the second distribution portion are each provided on an inner wall of the first supply passage and have a protrusion that projects radially outward from the inner wall, the protrusion being elongated along the circumferential direction of the housing.