Dustproof device of light path system in laser beam machine

摘要

The invention provides a laser beam machine having a light path duct with improved dust proof property. A light path system 1 of a laser beam machine comprises a light path duct 10 having a U-shaped cross-section with the upper end opened, wherein the opening portion is covered by a steel belt 30. The laser beam extraction unit 50 traveling on the light path duct 10 in the direction of arrow A elevates the steel belt 30 and extracts the laser beam from the light path duct 10. The steel belt 30 has a guiding projection 32 disposed at the center thereof. The laser beam extraction unit 50 has a guide roller 64 disposed below the steel belt 30 and a guide roller 62 having a V-shaped groove 62a for engaging the projection on the steel belt 30, thereby preventing displacement of the steel belt.