| The ultrasonic turning machining technology is a processing method based on ordinary turning,which applies ultrasonic signals to the turning tool to make forced vibration,thereby reducing the cutting force and improving the surface quality of the workpiece.With the continuous development of this technology,multi-dimensional ultrasonic composite processing technology such as two-dimensional elliptical ultrasonic turning has been born.The three-dimensional surface ultrasonic processing technology studied in this subject is based on this idea,which is based on one-dimensional ultrasonic vibration turning and two-dimensional elliptical ultrasonic vibration turning.The main research work of the thesis includes the following contents:(1)Based on the principle of three-dimensional curved ultrasonic turning,the vibration trajectory equation of the turning tool is deduced,and its vibration characteristics and material removal mechanism are analyzed.A three-dimensional curved ultrasonic turning system is established,and the components of the system are composed.The part and its functions were introduced and analyzed,and the dynamic components of the flexible hinge block unit were simulated by Abaqus software.(2)Based on the source and components of the cutting force during turning,a three-degree-of-freedom cutting force model is established.The model is not only suitable for cutting force prediction in general turning,but also suitable for ultrasonic assist turning process in various modes;MATLAB software was used to analyze the various factors affecting the cutting force,and predicte and simulating the cutting force of ordinary turning and three-dimensional curved ultrasonic turning under different cutting parameters,and different dimensional ultrasonic turning under the same cutting parameters.The cutting force of different dimensional ultrasonic turning under the same cutting parameters was also studied.(3)Based on the formation mechanism of the surface topography of the workpiece during turning,a discretization model of the surface topography of the workpiece for 3D curved ultrasonic turning was established.The surface topography of the workpiece after 3D curved ultrasonic turning was simulated by MATLAB software.The test carried out various factors affecting the surface roughness of the workpiece,including the variation of the surface roughness value under different cutting parameters and the difference between the surface morphology of the workpiece under different ultrasonic signals,and the surface at the time of ordinary turning.The morphology is also compared.(4)Based on the principle of three-dimensional curved ultrasonic turning and the deformation characteristics of a spiral grooved vibrating rod under a certain load,a spiral groove single-excitation three-dimensional curved ultrasonic turning device was designed,and the components of the device were carried out.The description and clarification of the specific method to realize the vibration trajectory of the three-dimensional curved surface of the turning tool;the kinematic model of the spiral groove transmitting vibration rod under the deformation of the load is established,and the vibration trajectory equation of the turning tool is derived;the spiral is solved by Abaqus software.The static vibration analysis of the trough-type vibrating rod was carried out,and its structural size was optimized. |
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