In the precision parts machining programming, the correct use of methods and technologies is of great significance to ensure and improve the machining accuracy of CNC machine tools. So what determines the precision of parts processing? The machining accuracy of CNC machine tool is determined by the position detection element, which is composed of the detection element (sensor) and the signal processing device, and is an important part of the closed-loop servo system of CNC machine tool.
Its function is to detect the actual value of the position and speed of the workbench, and send the feedback signal to the numerical control device or servo device, thus constituting a closed-loop control. The detection element generally uses the principle of light or magnetism to complete the detection of position or speed.
The position detection element is divided into direct measurement element and indirect measurement element according to the detection method. When measuring the linear motion of the machine tool, the linear detection element is generally used, which is called direct measurement, and the position closed-loop control formed is called full closed-loop control. The measuring accuracy mainly depends on the accuracy of the measuring element and is not affected by the machine driving accuracy.
Since the linear displacement of the machine table is proportional to the rotation Angle of the drive motor, the moving distance of the table can be measured indirectly by driving the method of detecting the rotation Angle of the motor or the lead screw, which is called indirect measurement, and the position closed-loop control composed of it is called semi-closed-loop control.
