Analysis of the causes of vibration in CNC machining center
The normal cutting process of the vibration process system generated by the CNC machining center during the machining process is disturbed and damaged. Vibration will not only aggravate the surface quality of machining, but also greatly shorten the service life of CNC machining centers and tools. In order to solve this problem well, first of all, we should check the causes of vibration in the CNC machining center.
When the low-frequency vibration occurs in turning, the workpiece system and tool rest system are usually vibrating. In most cases, the vibration of the workpiece system is relatively large. They are separated from time to time and close to each other from time to time, producing forces and reactions of equal magnitude and opposite directions.
During forward milling, the gap position between the lead screw and the nut is constantly changing, which will cause uneven feed of the workbench, resulting in impact and vibration, affecting the service life of the machine tool, the tool and the machined surface roughness of the workpiece. When using reverse milling, the cutting thickness changes from small to large, the tool load also changes from small to large, and the tool is more stable during processing.
Note that this is only used for finishing, but it is still necessary to use forward milling during rough machining, because the productivity of forward milling is high and the service life of the tool can be guaranteed. This may also be caused by the parameters of the system itself. A closed-loop system may also cause system vibration due to poor parameter setting. Forced vibration is caused by external periodic interference force. If the rotating parts on the machine tool are unbalanced, the centrifugal force generated when they rotate will excite the system, and the external vibration will be transmitted to the process system through the foundation, which will eventually lead to forced vibration of the process system.
The vibration sources of forced vibration include the internal vibration sources from the machine tool and the external vibration sources from the machine tool. There are many external vibration sources, but they are transmitted to the machine tool through the foundation.