The CNC pipe cutting machine movement chain includes numerical control device → servo encoder → servo drive → motor → lead screw → moving parts. According to the position of the position detecting device, it is divided into full closed loop control, semi closed loop control and open loop control.
1. Working principle of CNC cutting machine for full-closed control feed servo system
Position detection devices (such as grating scales, linear induction synchronizers, etc.) are mounted on the moving parts of the machine tool (such as the workbench), and the position of the moving parts is fed back in real time. After the CNC system processes, the machine status is notified to the servo motor, and the servo The motor automatically compensates for motion errors through system commands. However, since the large inertia links of the screw, the nut pair and the machine table are placed in the closed loop, it is troublesome to debug the system steady state during debugging. In addition, measuring devices such as grating scales and linear induction synchronizers are expensive and complicated to install, which may cause oscillations. Therefore, general machine tools do not use full-closed control.
2, semi-closed loop control feed servo system working principle of CNC pipe cutting machine
The position detecting device is installed at the end of the driving motor or the end of the screw rod for detecting the rotation angle of the screw or the servo motor, indirectly measuring the actual position of the moving parts of the machine tool, and feeding back to the control system via feedback. Due to the improvement of the mechanical manufacturing level and the improvement of the speed detecting component and the screw pitch precision, the semi-closed CNC machine tool has been able to achieve a relatively high feed accuracy. Semi-closed loop CNC systems are widely used by most machine tool manufacturers.
