Research On Dimensional Precision Of Slender Shaft In Double-tools Turning Process

As an important component part of the machine, the shaft played an irreplaceable role in supporting the rotated parts, transmission movement and torsion, so the precision of the shaft parts is very important to people. But when turning the slender shaft with lower rigidity and greater force, the easily arisen bending deformation, vibration and other factors that affect the actual volume of metal removed by cutting of tool increased the slender shaft cutting errors. It is difficult for the traditional cutting way to provide high precision for modern slender shaft machining, so people proposed the symmetrical dual-tools turning way, which weakened the radial force of slender shaft cutting force to a certain degree and reduced the degree of bending to improve machining accuracy.The paper, on the basis of analyzing the current situation of domestic and international dual-tool turning slender shaft and its characteristic of slender shaft, discussed the slender shaft machining methods, research on the characteristics of vibration in the process of machining, the application of the finite element method in turning the slender shaft, control and compensation of error and clamping mode of slender shaft and choosing parameters and other aspects. The paper, through reading and analyzing the literature, analyzed the sources of dual-tools slender shaft turning error and ultimately determined that the main reason why the dual-tools slender shaft bend and get the error is the tool cutting forces. Through the force analysis of the dual-tool slender shaft turning, the paper found that radial force is the main factor affect the slender shaft bending and deformation. And then analyzed the dual-tool slender shaft radial force to get the equation for bending and deformation of dual-tools slender shaft under the radial force. Moreover, the paper established dual-tools machining slender shaft error controlling model, set up PID closed-loop manufacturing system, design and install CCD online detecting system. Through collecting, analyzing and comparing the data of dual-tools machining after compensated PID pole error and dual-tools machining error without compensation, dual-tools turning machining error was significantly reduced after PID error compensation.At the end of this paper, through theoretical mechanics analysis and ANSYS Workbench simulation analysis,to find the most suitable cutting depth,feed and cutting speed of dual-tools turning machining,combined with the paper in the last part of the PID control compensation system and CCD online detection system more fully discusses the methods to reduce dimensional precision of slender shaft in double-tools.The results show that taking the compensation method to compensate the error of the size can significantly improve the accuracy of slender shaft turning and achieve the desired goal as well as provide an important basis for improving the accuracy of the follow-up slender shaft dual-tools turning machining.