What are the sources of laser cutting focus position error?

What are the sources of laser cutting focus position error?

 

During the laser cutting process, there are many factors that cause the relative position between the focal point and the surface of the object to be changed. The surface of the workpiece to be processed is uneven, the clamping mode of the workpiece, the geometric error of the machine tool, the deformation of the machine tool under load, and the workpiece Thermal deformation during processing will cause the laser focus position to deviate from the ideal given position (programmed position).   Some errors (such as the geometric errors of the machine tool) have regularity and can be compensated by quantitative compensation methods, but some errors are random errors that can only be eliminated by online detection and control. These errors are:   1. Geometrical errors of the workpiece during   laser cutting The object is a plate or cover type part. Due to various reasons, the surface of the processing object has unevenness, and the effect of thermal effects during the cutting process will also cause the surface deformation of the thin plate part. For 1D laser processing, the cover part is The surface unevenness will also occur during the press molding process. All of these will randomly change the position and ideal position of the laser focus and the surface of the object to be processed.

  2. Errors produced by the workpiece clamping device The   laser cutting workpiece is placed on the needle-shaped workbench. Due to processing errors, long-term wear and workpiece wear, and laser burns, the needle bed will be uneven, which is uneven Random errors in the position between the thin steel plate and the laser focus will also occur.   3. Errors generated by programming   In the process of 1D laser cutting, the machining trajectories on complex curved surfaces are fitted by straight lines, arcs, etc. There are certain errors between these fitting curves and actual curves. These errors make the actual focus and processing The relative position of the surface of the object and the ideal programming position produce a certain error. Some teaching programming systems also introduce some deviations.