Research On Movement Theory Of Lathe Of Turning Polygons And Design Of Its Prototype Model

Some parts are often designed to have noncircular sections to satisfy their functions during mechanical designing, such as polygon prisms, camshafts, crank, pistons,and so on. Compare with the routine parts with circular sections, the parts with noncircular sections have unique advantages on some occasion.With the development of manufacturing, the scale of he parts with noncircular sections is increasing. Their precision is also increasing for satisfying all kings of requiment. Correspondingly, the techniques for manufacturing the parts with high efficiency and high precision are focused now.It is difficult to machine a roung part to a polygon prism because the machining area is small and the machining precision is high. The method turning can keep the machining effiency and the precision of the part, so it can be applied. The method of vector modeling is used to study the movement theory of turning polygon prisms by the knowledge of comparative helix movement.Three projects is brought forward to turn polygon prisms, which are machining with tools moving radially, machining with the different tools angular velocities and turning approximative polygon prisms. Three projects are simulated for the best way can be taken, and their shortcomings and strongpoints are shown to prove that the third method is possible in experience. The trajectories of tool points are plotted, then the error of turning is calculated, and based on which multi-tool turning is put forward and its error is analysed also.The structure of the lathe to machine polygon prisms is framed according to the movement of turning approximative polygon prisms. An equipment is composed of a rotary tool fixture and a motor is designed to refit an old machine. In the equipment, the tool spindle is one of most important parts, so which is emphasized to be analysed. Its dynamic model is built, and the rigidity coefficient and damp coefficient of the bearings which support the spindle are deduced. By use of the finite element method, the dynamic characters of the tool spindle are got.The shortcomings of the former spindle are found based on the results of finite element analysis. It is analysed that the influence of the distance of the supportpoints, the mass of the tool fixture and the length of the spindle on the static and dynamic characters, and the structure of the tool spindle is optimized.The machining range and the whole project of the lathe are deduced based on the theories of designing CNC lathes and the movement theory of turning polygon prisms.The main parameters are get. Then the lathe of turning polygon prisms is made, and a servo motor is choiced to fit the equipment. The movements of every spindle of the lathe are dominated by a multi-spindle controller...