On the CNC machining center, due to the existence of errors such as the reverse dead zone of the driving parts on the feed transmission chain of each coordinate axis and the reverse gap of each mechanical motion transmission pair, the coordinate axis is changing from the forward movement to the reverse movement.
Reverse deviation is formed during movement, usually also called backlash or loss of momentum.
For CNC machining centers using semi-closed-loop servo systems, the existence of backlash will affect the positioning accuracy and repeat positioning accuracy of the machine tool, resulting in unstable machining accuracy, and will cause the machining parts to be round or square, and there will always be contour errors. . So how do we adjust the backlash of this kind of CNC machining center?
- Make mechanical adjustments first. Tighten the screw lock nut first. Check whether the screw shaft end coupling lock taper sleeve is loose or the coupling is damaged. The contact dye points of each guide rail and the plastic surface are uneven. , Re-precisely equip the shovel to make the contact surface dye point above 80%, and the 0.02mm feeler gauge is qualified.
- Check that the pre-tightening force of the screw nut of the CNC machining center is too strong or too loose. Adjust the pre-tightening force and check the axial rotation value so that the error is not greater than 0.005mm.
- Check that the end surface of the screw nut of the CNC machining center is not perpendicular to the joint surface, the joint is too loose, repair adjustment and repair treatment, the preload of the screw bearing seat is too tight or too loose to adjust and repair.
- The ball screw manufacturing error is large or the axial movement is large, and the control system can automatically compensate the gap to eliminate the gap. Use the instrument to measure and adjust the screw movement, the lubricating oil is insufficient or the lubricating oil of each guideway surface is not adjusted.