Detection And Control On CNC Lathe Processing System

In view of China's national conditions, relatively low-cost economy CNC lathe is still produced and used widely. The CNC Lathe also achieves machining accuracy, but can not meet the precision machining requirements. So improving machining accuracy of CNC lathe will become necessary. Now, the CNC lathe with Closed-loop control system has been existed, but that the terminal of Closed-loop control system is on worktable results in that not to reduce tool wear and thermal deformation and thermal deformation of the workpiece and other factors affect the accuracy of processing. To this end, this paper put forward a constructive manner to charge the terminal of control and detection devices into the workpiece being machined, and will open up a new way to improve the machining accuracy of CNC machine tools.To achieve the whole closed-loop function of the CNC lathe technology system, it is must depend on the combine of the online testing technics and the numerical control. Based on modern detection technics, utilizing CCD sensor inspects the workpieces being processed in real-time online, and feed the report back to NC system. Then, compareing discrepancy of the actural value and the theoretical value. If it is is in the given value bound, the NC system will continue next step; and vice versa, system send oder regulating the tool's feed to get the Value of the diameter of workpiece in the allowed bound, to achieve the whole closed-loop control of the CNC lathe system.The CCD system and its installation and CNC lathe vibration become a major factor in measurement accuracy. In the choice of light source, monochrome laser can meet a good coherence, and high degree of beam collimation requirements, and general light source is neither a parallel light source is not point the light , Therefore, the system uses laser as a light source.On this basis, in order to light a high degree of parallel light in the optical system,a diaphragm is added in the appropriate location to form a telecentric optical path, so that the radiation angle of the parallel light and further the measurement accuracy is improved. CCD device installation way in the CNC lathe ensures that the workpiece in the space of six degrees of freedom only in the Z axis and Y-axis rotation of the direction of moving before the impact of vibration on the image quality. And then through the MTF analysis method: the angular displacement of the workpiece on the impact of image quality is far greater than the impact of linear displacement. And the design methods of the above measures are to improve the accuracy of CNC lathe for machining centers, thus ensuring the maximum precision lathe processing.The article also exists on the actual detailed analysis of errors, and then pointed out the factors that caused the error and gives measures to reduce the error. The author set up mathematic model based on control theory, and analyse the dynamic and steady-state proformance of system. The research and analyse of system provide theoretical base for exploitation of high accuracy NC machines.In this paper, the existing closed-loop control thinking is breakthroughed, and a new NC lathe process system,including workpiece whole closed-loop control,has been creatively proposed.Meanwhile, Accuracy of detection and processing of the NC lathe is Improved greatly.it is also good promotional and revelatory action for the NC lathe's development.